Literatura académica sobre el tema "B12 vitamins"
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Artículos de revistas sobre el tema "B12 vitamins"
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Al- Joufi, Fakhria, Mona A. El- Bana, Ihab Tewfik y Mona Anwar. "EFFICACY OF COSUPPLEMENTATION THERAPY WITH VITAMINS B9, B12, AND D ON ENDOTHELIAL DYSFUNCTION IN STREPTOZOTOCIN-INDUCED DIABETIC RATS". Asian Journal of Pharmaceutical and Clinical Research 11, n.º 9 (7 de septiembre de 2018): 407. http://dx.doi.org/10.22159/ajpcr.2018.v11i9.25361.
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Objective: This study evaluated the effects of Vitamins D, B9, and B12 given individually or combined in ameliorating some biochemical parameters related to endothelial dysfunction in diabetic rats.Methods: A total of 50 Sprague-Dawley male rats were divided into five groups: Control, diabetic, diabetic received Vitamin D, diabetic received Vitamins B9 and B12, and diabetic received Vitamins B9, B12, and D. At the end of 6 weeks, the rats were sacrificed and a set of assays was carried out to determine: Fasting blood sugar (FBS), lipid profile, nitric oxide (NO), homocysteine (Hcy), malondialdehyde (MDA), and serum levels of Vitamins B9, B12, and D.Results: Diabetic rat received Vitamin D and diabetic rat received Vitamins B9 and B12 had a significant decline in the levels of FBS, lipid profile, and Hcy with reduced MDA (p<0.05) release but significant increase in NO level. On the same hand, diabetic rat received combined supplementation of Vitamins B9, B12, and D had more pronounced effect (p<0.00).Conclusion: Given these findings, the combined vitamins therapy had antiatherosclerotic effects by inhibiting lipid peroxidation and stimulating NO production, resulting in amelioration the endothelial dysfunction in diabetic rat.
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Mozos, Ioana, Dana Stoian y Constantin Tudor Luca. "Crosstalk between Vitamins A, B12, D, K, C, and E Status and Arterial Stiffness". Disease Markers 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/8784971.
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Arterial stiffness is associated with cardiovascular risk, morbidity, and mortality. The present paper reviews the main vitamins related to arterial stiffness and enabling destiffening, their mechanisms of action, providing a brief description of the latest studies in the area, and their implications for primary cardiovascular prevention, clinical practice, and therapy. Despite inconsistent evidence for destiffening induced by vitamin supplementation in several randomized clinical trials, positive results were obtained in specific populations. The main mechanisms are related to antiatherogenic effects, improvement of endothelial function (vitamins A, C, D, and E) and metabolic profile (vitamins A, B12, C, D, and K), inhibition of the renin-angiotensin-aldosterone system (vitamin D), anti-inflammatory (vitamins A, D, E, and K) and antioxidant effects (vitamins A, C, and E), decrease of homocysteine level (vitamin B12), and reversing calcification of arteries (vitamin K). Vitamins A, B12, C, D, E, and K status is important in evaluating cardiovascular risk, and vitamin supplementation may be an effective, individualized, and inexpensive destiffening therapy.
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Mantle, David. "Nutritional supplementation for vitamin B12 and vitamin K2 deficiency following ileostomy or colostomy formation". Gastrointestinal Nursing 18, Sup4 (1 de mayo de 2020): S12—S16. http://dx.doi.org/10.12968/gasn.2020.18.sup4.s12.
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Most dietary vitamins and minerals are absorbed from the duodenal and jejunal sections of the small bowel. The exceptions are vitamin B12 and vitamin K2, which are absorbed from the terminal ileum and colon respectively. Patients who have undergone ileostomy or colostomy procedures are at risk of deficiency of these vitamins, with associated risk of developing anaemia and nervous system dysfunction (vitamin B12), and bone weakening and cardiovascular disease (vitamin K2). Patients should therefore be monitored for deficiency of these vitamins, which may develop over a protracted period of time. Patients lacking the terminal ileum or colon can still absorb supplemental vitamins B12 or K2 given orally, provided a sufficient loading dose is given to facilitate absorption from the remaining gastrointestinal tract.
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Lai, Jun S., M. Na’im Mohamad Ayob, Shirong Cai, Phaik Ling Quah, Peter D. Gluckman, Lynette P. Shek, Fabian Yap et al. "Maternal plasma vitamin B12 concentrations during pregnancy and infant cognitive outcomes at 2 years of age". British Journal of Nutrition 121, n.º 11 (2 de abril de 2019): 1303–12. http://dx.doi.org/10.1017/s0007114519000746.
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AbstractEvidence on long-term influences of maternal vitamin B12 deficiency or concentrations on infant cognition is limited. We examined associations between maternal plasma vitamin B12 and cognitive development in 24-month-old infants. Maternal plasma vitamin B12 concentrations were measured at 26–28 weeks’ gestation; infant cognitive development was assessed with the Bayley Scales of Infant and Toddler Development-III at 24 months, for 443 mother–infant pairs from the Growing Up in Singapore Towards Healthy Outcomes cohort. Linear regressions adjusted for key confounders examined associations of maternal vitamin B12 with cognitive, receptive and expressive language, fine and gross motor subscales. Co-occurrence of maternal vitamin B12 with folate or vitamin B6 insufficiencies on child’s cognition was explored. Average maternal plasma vitamin B12 concentrations was 220·5 ± 80·5 pmol/l; 15 % and 41 % of mothers were vitamin B12 deficient (<148 pmol/l) and insufficient (148–220·9 pmol/l), respectively. Infants of mothers with vitamin B12 deficiency had 0·42 (95 % CI −0·70, −0·14) sd lower cognitive scores, compared with infants of mothers with sufficient vitamin B12. Co-occurrence of maternal vitamins B12 and B6 insufficiencies was associated with 0·37 (95 % CI −0·69, −0·06) sd lower cognitive scores in infants compared with infants of mothers sufficient in both vitamins. No significant associations were observed with other subscales. Study findings suggest the possible need to ensure adequate vitamin B12 during pregnancy. The impact of co-occurrence of maternal B-vitamins insufficiencies on early cognitive development warrants further investigation.
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Rezazadeh, Fahimeh y Sara Haghighat. "Serum Vitamin Profile in Oral Lichen Planus Patients in Southwest of Iran". BioMed Research International 2021 (24 de febrero de 2021): 1–7. http://dx.doi.org/10.1155/2021/8627435.
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Introduction. Oral lichen planus (OLP) is a chronic mucocutaneous disease. It is mainly an immune system-related disorder. Vitamins can modulate immune system functions, and thus, vitamin deficiency might have roles in exacerbating OLP. We aim to determine the serum levels of vitamins A, B12, C, D3, and E in OLP patients. Methods and Materials. 34 OLP patients referred to Shiraz Dental School entered the study. Blood samples were collected and levels of A, B12, C, D3, and E vitamins were measured in serum. 43 healthy people were also included as the control group. Serum levels of vitamins were measured by HPLC (A, B12, D3, and E) and Kiazist analyzing kit (vitamin C). Results. Most of the patients were female (62.3%), and the mean age of patients was 48.03 ± 11.57 . Serum levels of vitamins A, C, and E were lower in OLP patients in comparison with the healthy group; however, the difference was not significant. Vitamins B12 and D3 were higher in the OLP group but the difference was not significant. Conclusion. Serum levels of vitamins A, B12, C, D3, and E do not have a significant difference in OLP patients and healthy groups. These vitamins may not have a considerable role in OLP pathogenesis in the southwest of Iran.
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El-Kholy, Mohamed Soliman, Zenat Abd El-Gawad Ibrahim, Mohamed Mamdoh El-Mekkawy y Mahmoud Alagawany. "Influence of in Ovo Administration of Some Water-Soluble Vitamins on Hatchability Traits, Growth, Carcass Traits and Blood Chemistry of Japanese Quails". Annals of Animal Science 19, n.º 1 (1 de enero de 2019): 97–111. http://dx.doi.org/10.2478/aoas-2018-0041.
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AbstractA total of 450 fertile Japanese quail eggs were used to determine the impacts of in ovo administration of water-soluble vitamins (C, B6 and B12) on the growth performance, carcass traits, hematological and biochemical blood parameters as well as the immune response of Japanese quails. On the 7th day of incubation, the eggs were allocated to five groups: un-injected, 0.1 ml/egg saline, 1 mg/egg vitamin C, 150 µg/egg vitamin B6 and 20 µg/egg vitamin B12. The percentage of early embryonic mortality was increased (P≤0.001) in all treated groups versus the control group. Chicks that hatched from eggs injected with 1 mg/egg vitamin C exhibited a significantly greater (P≤0.05) live body weight (LBW) than those from the control and saline groups. During 0–2 weeks of age, the chicks hatched from eggs injected with vitamins displayed better feed conversion than the positive or negative controls. In ovo injection of vitamins had no significant effect on all carcass traits. In ovo injection with vitamins C, B6 and B12 increased plasma total protein and its fractions compared with the control. Plasma levels of total lipids and cholesterol were decreased in chicks hatched from eggs injected with 1 mg/egg vitamin C, 150 µg/egg vitamin B6 or 20 µg/egg vitamin B12 compared with those hatched from control eggs. Plasma T3 and T4 were increased in chicks hatched from eggs injected with vitamin C, vitamin B6 and vitamin B12. The relative weights of the bursa of Fabricius and thymus were significantly (P=0.002 or 0.003) increased in the birds hatched from eggs injected with vitamins compared with those in the control or saline group. Thus, in ovo injection of vitamins C, B6 and B12 improved the blood profile and immune response of Japanese quail.
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Girard, C. L. y J. J. Matte. "Impact of B-vitamin supply on major metabolic pathways of lactating dairy cows". Canadian Journal of Animal Science 86, n.º 2 (1 de junio de 2006): 213–20. http://dx.doi.org/10.4141/a05-058.
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Knowledge of the major nutrient requirements of dairy cows has increased substantially during the past decades. Little is known, however, about the importance of the roles played by B vitamins. Since most of those vitamins act as essential cofactors in energy, protein and lipid metabolism, it is likely that as milk yield increases, the demand for these cofactors also increases. The supply of B vitamins from dietary sources and synthesis by the ruminal microflora is generally sufficient to avoid deficiency symptoms, but could be insufficient for optimizing metabolic efficiency, production, composition and the nutritional quality of milk in high-producing dairy cows. Results from recent experiments show how the supply of three B vitamins — folic acid, biotin and vitamin B12 — affects major metabolic pathways. Supplementary biotin has frequently been reported to increase milk yield but has a limited effect on milk composition. Folic acid supplements have been found to increase milk and milk protein yields in multiparous cows without affecting dry matter intake when vitamin B12 supply was adequate. An insufficient vitamin B12 supply blocked those effects but they can be restored through vitamin B12 supplementation. Supplemental vitamin B12 and biotin increased milk and milk protein yields without changing dry matter intake. Vitamin B12 utilization by tissues increased in cows fed supplementary folic acid simultaneously; plasma glucose also increased in these cows but plasma biotin decreased. From these findings, it appears that, in high-producing dairy cows, especially in early lactation, the strong competition for nutrients that occurs between gluconeogenesis, methylneogenesis and protein synthesis increases the amount of folic acid, vitamin B12 and biotin required to maintain metabolic efficiency, especially when the nutrient supply is limited. These observations emphasize the need to review the paradigm according to which B-vitamin supply by ruminal microflora cannot be limiting in dairy cow. Key words: Dairy cow, B vitamins, folic acid, vitamin B12, biotin, lactation, metabolism
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Baltrusch, Simone. "The Role of Neurotropic B Vitamins in Nerve Regeneration". BioMed Research International 2021 (13 de julio de 2021): 1–9. http://dx.doi.org/10.1155/2021/9968228.
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Damage and regeneration naturally occur in the peripheral nervous system. The neurotropic B vitamins thiamine (B1), pyridoxine (B6), and cobalamin (B12) are key players, which maintain the neuronal viability in different ways. Firstly, they constantly protect nerves against damaging environmental influences. While vitamin B1 acts as a site-directed antioxidant, vitamin B6 balances nerve metabolism, and vitamin B12 maintains myelin sheaths. However, nerve injury occurs at times, because of an imbalance between protective factors and accumulating stress and noxae. This will result in the so-called Wallerian degeneration process. The presence of vitamins B1, B6, and B12 paves the way out to the following important regeneration by supporting the development of new cell structures. Furthermore, vitamin B1 facilitates the usage of carbohydrates for energy production, whereas vitamin B12 promotes nerve cell survival and remyelination. Absence of these vitamins will favor permanent nerve degeneration and pain, eventually leading to peripheral neuropathy.
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Fahad Aldaihani, Saad. "VITAMIN DEFICIENCY AND FOOD SUPPLEMENTS". International Journal of Advanced Research 9, n.º 12 (31 de diciembre de 2021): 540–52. http://dx.doi.org/10.21474/ijar01/13941.
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Vitamins are a heterogeneous group of organic compounds that help ensure the human bodys wellbeing and function. This paper introduces the importance of all vitamins, both water-soluble and fat-soluble, as well as problems deriving from their deficiency. Additionally, vitamin supplements as part of treating vitamin deficiency, and possible harmful effects on the human body areshowcased. The main focus of the paper is on the vitamin B complex, and vitamin B12 specifically. The benefits of vitamin B12, as well as its action in the human body and the noxious effects of any lack of vitamin B12 in the human body, are also discussed. Some of the health conditionsan individual may need to face when they have vitamin B12 deficiency include neural tube defects, Alzheimers disease, depression, and megaloblastic anaemia, which are also introduced and further discussed, in terms of symptomatology, causes and suggested treatment. The toxicity of vitamin B12 is also introduced, and possible causes for vitamin B12 deficiency are showcased.
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Ismael Ibrahim, Gulzar, Hemn Jameel Majeed, Pshtiwan Abdullah Yousif y Saman Muhsin Abdulkareem. "Association between Serum Levels of Vitamin D, Vitamin B12 and Folate with Oxidative Biomarkers in Diabetic Type 2 Patients in People in Erbil City: A Case-Control Study". Diyala Journal of Medicine 19, n.º 2 (15 de diciembre de 2020): 200–207. http://dx.doi.org/10.26505/djm.19025660915.
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Background: Diabetes mellitus is the largest endocrine disorder in the world that refers to chronic hyperglycemia caused by impairment in both insulin secretion and action. Folate, vitamin B12, and vitamin D deficiency are related to the prevalence of type 2 diabetes mellitus. Objective: This study has been carried out to investigate the role of folate, vitamins B12, and D status during the progression of diabetic type 2 patients compared to non-diabetic control subjects. Patients and Methods: We measured the plasma levels of folate, vitamins B12, and D, along with blood glucose, HbA1c, and oxidative biomarkers in 50 diabetic type 2 patients and 50 healthy subjects used as a control group. Results: The findings revealed that the serum level of malondialdehyde (MDA) significantly increased in diabetic patients compared to healthy subjects, and the serum level of nitric oxide (NO) in T2D patients lower than in control. The concentration of vitamin D, B12, and folate in T2D patients significantly lower than non-T2D control. The results also showed a significant relationship between serum vitamin D, MDA, and NO with HbA1c, while there was an insignificant correlation between vitamin B12 and folate with HbA1c. Conclusion: The oxidative biomarkers and vitamins D, B12, and folate level can play an important role in the development and progression of T2D. Keywords: Oxidative Stress, Vitamin D, Vitamin B12, Folic acid, type 2 diabetes
Tesis sobre el tema "B12 vitamins"
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Presoto, Ana Elisa Ferreira. "Vitaminas do complexo B e ferro em farinhas de cereais". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-21112017-145753/.
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As vitaminas do complexo B e o ferro estão presentes em farinhas de cereais, alimentos amplamente consumidos pela população brasileira. O teor natural desses compostos em farinhas de cereais pode ser significativo no cálculo de uma dieta bem balanceada e o consumo de produtos industrializados enriquecidos com vitaminas do complexo B e ferro ajuda a contribuir na ingestão diária recomendada desses micronutrientes. Tabelas Mundiais de Composição de Alimentos apresentam dados incompletos das vitaminas do complexo B e do ferro em farinhas de cereais. No Brasil, a adição de ácido fólico e ferro em farinhas de milho e trigo produzidas para fins industriais é obrigatória desde 2002. Deste modo, para a adequação dos teores de rotulagem de produtos enriquecidos com vitaminas e ferro se fazem necessários o desenvolvimento e a validação de metodologias analíticas confiáveis e sensíveis para análise de vitaminas do complexo B e ferro em alimentos que apresentam tais micronutrientes em quantidades baixas, porém significativas, que correspondem aos teores naturalmente presentes. O objetivo do presente trabalho é a avaliação dos teores de sete vitaminas do complexo B (B1, B2, B6, ácido pantotênico, ácido fólico, niacina e biotina) e ferro em cinco farinhas de cereais (aveia, arroz, cevada, milho e trigo) utilizadas como matéria prima de produtos enriquecidos na indústria alimentícia, utilizando métodos validados.Complex B vitamins and iron are present in some cereal foods, a kind of food largely consumed by Brazilian people. The total of these micronutrients can be significant at the dairy ingestion portion and in the consume of industrialized products enriched with complex B vitamins and iron contribute in the recommended dietary intake of these micronutrients. Table of food composition do not report complete data of complex B vitamins and iron in cereal flours. In Brazil, since 2002 the addition of folic acid and iron in com and wheat flours is compulsory. Therefore, to adapt the label of some products enriched with vitamins and iron, there is necessary the development and validation of analytical methods. These methods must be reliable and with enough sensitivity to analyse complex B vitamins and iron, in low concentration, wich are natural content in food. The purpose of this work is the evaluation, with validated methods, of the content of seven complex B vitamíns (B1, B2, B6, niacin, folic acid, pantothenic acid and biotin) and iron in five kinds of cereal flours (oat, rice, barley, com and wheat). These raw materiais are used in food industry in order to enrich the industrialized products.
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Steluti, Josiane. "Folato, vitamina B6 e B12: Ingestão dietética, níveis sanguíneos e relação com a concentração sérica de homocisteína em adolescentes de Indaiatuba, SP". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/6/6138/tde-17112010-120013/.
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Introdução: O folato e outras vitaminas do complexo B estão metabolicamente relacionadas à elevação sanguínea do aminoácido homocisteína (hcy). Este, por sua vez, se mostrou associada ao aumento de risco de eventos adversos, sobretudo as doenças cardiovasculares. Objetivo: Investigar a ingestão dietética e níveis sanguíneos das vitaminas folato, B6, e B12, e sua relação com a concentração sérica de hcy, entre adolescentes Métodos: Estudo observacional, transversal, em adolescentes de ambos os sexos, faixa etária de 16 a 19 anos, foi conduzido na escola de ensino técnico da cidade de Indaiatuba-SP-Brasil. Coletou-se registro alimentar de três dias não consecutivos. Os valores dos nutrientes referentes aos registros foram obtidos no software NDSR. Para a estimativa da dieta habitual pela remoção da variabilidade intrapessoal e a prevalência de inadequação da ingestão pelo método da EAR como ponto de corte, utilizou-se o PC-Side, versão 1.0. As análises bioquímicas de folato, B6, B12 e hcy foram conduzidas de acordo com os métodos aceitos na literatura científica. Todas as análises estatísticas foram realizadas no STATA® versão 10.0 considerando o nível de significância 5%. Resultados: O estudo foi conduzido com 99 adolescentes, sendo 58,6% do sexo feminino e média de idade de 17,6 (dp 0,9) anos. As médias da concentração sérica de folato, B6 e B12 foram de 9,2 (dp 3,4) ng/ml, 18,7 (dp 5,1) nmol/L e 397,5 (dp 188,4) pg/ml, respectivamente. 15,2% dos adolescentes apresentavam inadequação da ingestão de folato, 10,2%, de B6 e <1%, de B12. Os alimentos que mais contribuíram para a ingestão dos nutrientes foram: pão francês (23,1%), macarrão (9,7%) e feijões (8,2%) para folato; arroz branco (9,9%), carne de frango (5,7%) e carne bovina (4,2%) para B6, e carne bovina magra (16,4%), leite integral (15%) e carne bovina gorda (12,3%) para B12. Em relação à hcy, as médias foram de 15,4 (dp 10,2) µmol/L nos meninos e 8,2 (dp 2,2) µmol/L nas meninas. Dos meninos, 25% apresentavam valores séricos de hcy superiores a 15 µmol/L e diminuição da média sérica de folato e B12 quanto maior o tercil do nível sérico hcy (p<0,005). Conclusão: As prevalências de inadequação da ingestão folato, B6 e B12 mostraram-se baixas, possivelmente em decorrência da melhoria do acesso e disponibilidade de alimentos, inclusive dos alimentos processados que contêm entre os ingredientes as farinhas fortificadas com ácido fólico. No entanto, os feijões, ainda se destacaram como um dos alimentos que contribuíram para a ingestão desse nutriente. Além disso, os adolescentes do sexo masculino têm altos níveis séricos de hcy e apresentaram uma tendência de queda das médias da concentração sérica de folato e B12 quanto maior o tercil de hcy.Introduction: Folate and the metabolically related B vitamins are intimately connected with metabolic pathways of homocysteine (hcy). Epidemiologic studies have shown that increased total homocysteine concentration is an independent predictor for a number of human diseases, especially, cardiovascular diseases. Objective: to investigate the dietary intake and status of folate, related B-vitamin, and the relationship to total homocysteine concentration among adolescents. Methods: A cross-sectional study was conducted among adolescents, both genders, aged 16 to 19 years, in a public school of Indaiatuba, São Paulo. Dietary intake was measured using three-day dietary record. The energy and nutrients were computed using Nutrition Data System for Research software. The usual intake and prevalence of inadequate by EAR cut-point method were estimated using PC-SIDE, version 1.0. Biochemical analyses were determined according the methods recommended by the scientific literature. All statistical analyses were performed using STATA, version 10.0. A two-tailed p value <0.05 was considered significant. Results: The study was conducted among 99 adolescents, 58 (58.6%) were girls, mean age of 17.6 (SD 0.9) years old. The means of folate, B6 and B12 vitamins status were of 9.2 (SD 3.4) ng/ml, 18.7 (SD 5.1) nmol/L and 397.5 (SD 188.4) pg/ml, respectively. The proportion of adolescents with folate, B6 and B12 intakes above the recommendation was 15.2%, 10.2%, e <1%, respectively. The foods that more contributed for folate intake were French bread (23.1%), pasta (9.7%) and beans (8.2%). For B6 intake rice (9.9%), chicken (5.7%) and meat (4.2%). For B12 intake, meat without fat (16.4%) whole milk (15%) and meat with fat (12.3%). The mean of hcy was 15.4 (SD 10.2) µmol/L in boys and 8.2 (SD 2.2) µmol/L in girls. In boys, 25% of them showed values of serum hcy concentration upper to 15 µmol/L and, means of folate and vitamin B12 decreased according of serum hcy tercil (p<0.005). Conclusions: The prevalence of inadequate intake of folate, vitamin B6 and B12 were low, possibly due to improved access and availability of food, including processed foods that contain the fortified flour with folic acid as ingredient. However, the beans, a component of the Brazilians usual dietary pattern, are founded as important contributors of folate intake. The total homocysteine levels were higher in boys when compared with girls. In boys, folate and vitamin B12 status were decreased significantly with trend among different tercile serum homocysteine concentration.
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Beauvais, Maxime. "Long term seasonality of microbial vitamin B1 and B12 metabolisms and their potential interplay in the Northwestern Mediterranean Sea". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS641.
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L'environnement façonne les communautés microbiennes qui dirigent les cycles biogéochimiques des océans, mais les facteurs biotiques sont également d’important déterminants dans la structure des communautés. Ces systèmes dynamiques sont composés d'espèces cooccurrentes structurées dans un réseau complexe d'interactions entre organismes et avec leur environnement. Les vitamines B1 et B12 sont des cofacteurs essentiels mais la plupart des microbes marins incluant de nombreuses espèces de phytoplancton, ne peuvent pas les produire eux-mêmes (auxotrophes aux vitamines). De plus, les vitamines B1 et B12 sont rares dans l’océan. Ensemble, ces observations soulèvent la question suivante : comment les auxotrophes assurent-ils leurs besoins en vitamines dans l’océan ? Cette question reste en grande partie sans réponse car la saisonnalité des auxotrophes et leur interaction avec les producteurs de vitamines restent peu étudiées. Pour combler ces lacunes, nous avons réalisé une série temporelle métagénomique mensuelle sur 7 ans dans un site côtier de Méditerranée Nord-Ouest (station SOLA) afin d'évaluer la saisonnalité à long terme des communautés procaryotes, en se focalisant sur les métabolismes des vitamines B1 et B12 et leur interaction potentielle au cours des saisons. Tout d'abord, nous avons mis en évidence une succession saisonnière de différents organismes pouvant utiliser des voies distinctes pour produire de la B12 tout au long de l'année. En été, les bactéries du genre HIMB11, UBA8309 et Puniceispirillum peuvent utiliser la voie de production aérobie, tandis qu'en hiver, les archées du genre Nitrosopumilus et Nitrosopelagicus peuvent utiliser la voie de production anaérobie. Ensuite, nous avons montré que lors de perturbations environnementales, les organismes habituellement porteurs de gènes de synthèse de la B12 sont remplacés par d'autres porteurs du même gène (redondance fonctionnelle), maintenant ainsi le potentiel de production de B12. Cette assurance écologique pourrait contribuer à la résilience fonctionnelle à long terme des communautés microbiennes marines exposées à des conditions environnementales interannuelles contrastées. Deuxièmement, nous avons montré que les communautés procaryotes à SOLA étaient dominées par des auxotrophes HMP (Pelagibacter), dont l'abondance était plus élevée en été avec d’autre auxotrophes plus rares (doubles HET/HMP, comme HIMB59), et par des auxotrophes B1 (HIMB11), qui étaient présents tout au long de l'année. À SOLA, nous avons rapporté une plus grande contribution des producteurs de B1 que précédemment observé dans d'autres régions, incluant des bactéries (Pseudothioglobus, MB11C04), des cyanobactéries (Synechococcus) et des archées (Nitrosopumilus). Les expériences de bio-essais ont montré de multiples périodes de limitation en vitamines et précurseurs dans l'eau de mer pendant les mois d'hiver. En outre, l'ajout de vitamines et de précurseurs a eu un impact significatif sur la structure de la communauté procaryote dans nos microcosmes, en particulier en Février. Différents ASV ont été sélectivement favorisés par différentes conditions pendant la transition hiver/printemps. Cependant, la réponse des communautés reste difficile à démêler sachant que les auxotrophes et les prototrophes sont impactés par l’ajout de vitamines/précurseurs. Enfin, grâce à l’assemblage de MAGs et en identifiant leurs potentiels de production pour la B1 et la B12, nous avons montré des schémas de cooccurrence forts et récurrents entre les auxotrophes et les producteurs de vitamines, reflétant différentes complémentarités fonctionnelles potentielles en fonction des saisons. La double complémentarité pour la B1 et la B12 était prédominante dans le réseau de cooccurrence d’été (un auxotrophe B1/B12 avec un prototrophe B1/B12), tandis que la simple complémentarité pour la B1 ou la B12 était prédominante dans les cooccurrences d'hiver (un auxotrophe B1/producteur de B12 avec un producteur de B1/auxotrophe B12)The environment shapes marine microbial assemblages that drive ocean biogeochemical cycles, but biotic interactions are also strong community structuring factors. Marine microbial communities are dynamic systems of co-occurring species structured as a complex network of interactions, including microbe to environment and microbe to microbe connections. B-vitamins are essential cofactors of critical cellular processes, and most marine microbes, including many phytoplankton species require an exogenous source of vitamins or precursors to grow (i.e., vitamin or precursor auxotrophs). Despite their ecological importance, B1 and B12 are scarce in most oceanic and coastal regions. Together, the widespread vitamin scarcity observed in oceans and the high incidence of vitamin auxotrophy raises the question of how vitamin auxotrophs ensure their vitamin requirements in a large and diluted environment? This question remains largely unanswered as the seasonality of vitamin auxotrophs and their interplay with vitamin producers remain poorly studied. To tackle these knowledge gaps, we conducted a 7 years monthly metagenomic time series in the coastal NW Mediterranean Sea (SOLA station) to assess the long-term seasonality of planktonic prokaryotic communities, with a focus on B1 and B12 metabolisms and their potential interplay over time.First, we highlighted a seasonal succession of different organisms which could use distinct biosynthesis pathways to produce B12 de-novo along the year. In summer, bacteria belonging to the genera HIMB11, UBA8309 and Puniceispirillum could use the aerobic B12 production pathway, while in winter, Thaumarchaeota belonging to Nitrosopumilus and Nitrosopelagicus genera could use the anaerobic B12 production pathway. Then, we show that during irregular environmental perturbations observed in winter at SOLA station, organisms usually carrying B12 synthesis genes are replaced by others with the same gene (i.e., functional redundancy), thus maintaining the potential for B12 production. Such ecological insurance could contribute to the long-term functional resilience of marine microbial communities exposed to contrasting inter-annual environmental conditions. Secondly, we showed that SOLA prokaryotic communities were dominated by HMP auxotrophs (Pelagibacter, AAA536-G10, Litoricola), which had higher abundances in summer together with the rarer dual HET/HMP auxotrophs (HIMB59, HIMB100, Octadecabacter), and by B1 auxotrophs (HIMB11, Puniceispirillum), which were present throughout the year. At SOLA, we reported a larger contribution of B1 producers than previously reported in other regions, including bacteria (Pseudothioglobus, MB11C04), cyanobacteria (Synechococcus, Prochlorococcus) and archaea (Nitrosopumilus, Nitrosopelagicus). Bioassays experiments using showed multiple vitamin and precursor limitations periods in SOLA seawater during winter months. Moreover, the addition of vitamins and precursors had a significant impact on prokaryotic community structure in our microcosm’s experiments, especially in February. Different ASVs were selectively promoted by different conditions during the winter/spring transition (B12, H+C and B1+B12). However, the differential response of communities remains difficult to disentangle, given that both vitamin auxotrophs and prototrophs were promoted during our incubations. Finally, by assembling high-quality metagenome assembled genomes (MAGs) and identifying their B1 and B12 lifestyles, we highlight strong and recurrent co-occurrence patterns between vitamin auxotrophs and producers reflecting different potential functional complementarities between them depending on the season. Double complementarity for B1 and for B12 was prevalent in summer co-occurrences networks (e.g., B1/B12 auxotroph co-occur with B1/B12 prototroph), while simple complementarity for B1 or B12 was prevalent in winter co-occurrences (e.g., B1 auxotroph / B12 producer co-occur with B1 producer/B12 auxotroph)
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McMahon, Jennifer A. y n/a. "The effect of homocysteine lowering vitamins on cognitive performance in older people : a randomised controlled trial". University of Otago. Department of Human Nutrition, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070426.154857.
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Background: Inverse associations have been reported between homocysteine concentrations and poor cognitive performance in several cross-sectional studies of healthy elderly subjects. Folate supplementation with or without vitamins B-12 and B-6 is an effective means of lowering homocysteine concentrations. Mood disturbances, from mild mood changes to clinical depression, are common in older populations. Several studies have shown that depressed people have lower levels of folate and vitamin B-12 and higher levels of homocysteine than non-depressed people. Improvement of mood has been reported in depressed people following supplementation with folic acid. Clinical trials are required to determine if lowering homocysteine concentration with vitamins improves cognitive function and/or mood in healthy elderly participants.
Objective: The primary aim of this research project was to carry-out a 2 year randomised, double-blind, placebo-controlled trial to determine if a supplement containing folate (1mg L-Mefolinic acid), vitamin B-12 (500(mu)g) and vitamin B-6 (10mg) improves scores or prevents decline on tests of cognition in a group of healthy older people ([greater than or equal to]̲ 65 years) with a plasma homocysteine concentration [greater than or equal to]̲13 (mu)mol/L. A second aim of this study was to determine if homocysteine lowering vitamins improved scores on tests of mood in this group.
Methods: Four hundred and sixty-five individuals, aged 65 and over, were recruited from Dunedin and surrounds, and asked to attend a screening clinic and provide a fasting blood sample. Two-hundred and seventy-six volunteers with a plasma homocysteine concentration [greater than or equal to]13(mu)mol/L were randomised to take either a combination of 1mg L-Mefolinic acid, 500(mu)g vitamin B-12 and 10mg vitamin B-6 or placebo for 2 years. A battery of cognitive tests and indices of mood was administered at baseline, one year, and two years. A fasting blood sample was collected at baseline and every six months thereafter.
Results: From baseline to 6 months of the intervention, homocysteine concentrations decreased by 37.5%, from 16.7 to 10.5 (mu)mol/L in the vitamin supplemented group and then plateaued. In the vitamin supplemented group there was a 181% increase in red blood cell folate concentration from a mean of 977 to 2752 nmol/L, and a 90.1% increase in plasma vitamin B-12 (from a mean 283 to 538 (mu)mol/L) over the study period of two years.
In the vitamin supplemented group there was a trend to poorer performance on almost all tests of cognition compared to placebo group. The vitamin group was 8% slower on Part B of the Reitan Trail Making Test, a test of speeded attention, mental tracking, visual search and mental flexibility (p=0.009). The vitamin group scored significantly lower on tests of short-term recall, Weschler Paragraphs (p=0.03) after 2 years, and the Rey Auditory Verbal Learning Test ((p=0.04) after one year, than the placebo group. There was no difference in mood score by treatment in this largely non-depressed group.
Conclusion: These results suggest a detrimental effect of high dose homocysteine lowering vitamin supplements on cognitive function in healthy older people. These results need to be confirmed in other randomised controlled trials.
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Barnabé, Aline 1982. "Avaliação da concentração de 2,3-difosfoglicerato, homocisteina plasmatica, acido folico, vitamina B12 e polimorfismos no gene da MTHFR em pacientes com doença pulmonar obstrutiva cronica". [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311374.
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Orientadores: Nelci Fenalti Hoehr, Joyce Annichino-BizzacchiDissertação (mestrado) - Universidade Estadual de Campinas. Faculdade de Ciencias Medicas
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Resumo: A Doença Pulmonar Obstrutiva Crônica (DPOC) é caracterizada por obstrução do fluxo aéreo que envolve um processo inflamatório crônico das vias aéreas e destruição do parênquima pulmonar induzidos pela bronquite crônica ou enfisema. Devido às anormalidades na troca gasosa que ocorre na DPOC, mudanças no pH podem alterar as concentrações de 2,3-difosfoglicerato (2,3-DPG), um fosfato orgânico presente nos eritrócitos e que exerce função importante no transporte de oxigênio. A baixa concentração de 2,3-DPG aumenta a afinidade do oxigênio à hemoglobina, dificultando sua liberação, comprometendo a oxigenação dos tecidos. Além disso, oxigenioterapia indicada para pacientes com DPOC pode levar a produção de espécies reativas de oxigênio (EROS) responsáveis pela injúria celular. Por outro lado, EROS também pode ser produzido por um aumento nos níveis de homocisteína no plasma e com isso causar lesão celular. Estudos sugerem que pacientes com DPOC podem apresentar aumento da homocisteína plasmática, um fator de risco para doenças cardiovasculares. Baseando-se nisso, o objetivo deste estudo foi avaliar os níveis de 2,3-DPG e homocisteína em pacientes com DPOC. Nossos resultados mostraram que não houve diferença na concentração de 2,3-DPG entre pacientes e controles, pois a concentração desse fosfato foi semelhante em ambos os grupos. Nos pacientes com DPOC que fazem uso ou não de oxigenioterapia também não houve diferença nas concentrações de 2,3-DPG. Portanto, o transporte e distribuição de oxigênio não estavam prejudicados nesses pacientes. No entanto, os pacientes com DPOC apresentaram hiperhomocisteinemia leve e baixos níveis de ácido fólico. Esta observação sugere a necessidade de suplementação com ácido fólico para pacientes com DPOC. Os polimorfismos C677T e A1298C no gene da MTHFR não influenciaram as concentrações de homocisteína nos pacientes com DPOC. A contribuição de nossos dados é de grande importância para o monitoramento de pacientes com DPOC.
Abstract: Chronic Obstructive Pulmonary Disease (COPD) is characterized by chronic airflow obstruction that involves a chronic inflammation of the airways and destruction of lung parenchyma induced by chronic bronchitis or emphysema. Abnormalities in gas exchange that occurs in COPD leads to changes in pH altering 2,3-DPG levels, an organic phosphate present in red blood cells and play an important role in oxygen transport. Reduced levels of 2,3-DPG increase the oxygen affinity of hemoglobin and reduces oxygen delivery, compromising tissue oxygenation. On the other hand, oxygen therapy which is used in COPD patients induces the production of reactive oxygen species (ROS) responsible for cellular injury. ROS can be also produced by an excess of homocysteine in plasma. Studies suggest that COPD patients may have increased homocysteine, a risk factor for cardiovascular diseases. The aim of the present study was to evaluate 2,3-DPG and homocysteine levels in COPD patients. Our results showed no difference in the 2,3-DPG levels between patients and controls. In patients with COPD who use oxygen therapy or not there was no difference in the 2,3-DPG. Therefore, oxygen transport and unloading were not affected. Patients with COPD had mild hyperhomocysteinemia and low levels of folic acid. This observation suggests that dietary supplement of folate to COPD patients is necessary. C677T and A1298C polymorphisms in the MTHFR gene showed no influence on concentrations of homocysteine in COPD patients. Our data make an important contribution for the monitoring of COPD patients.
Mestrado
Ciencias Biomedicas
Mestre em Ciências Médicas
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Potter, Kathleen. "The effects of long-term homocysteine-lowering treatment with folic acid, vitamin B6 and Vitamin B12 on vascular structure and function in stroke". University of Western Australia. School of Medicine and Pharmacology, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0020.
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[Truncated abstract] An elevated total plasma homocysteine concentration (tHcy) is associated with an increased risk of myocardial infarction and ischemic stroke. Folic acid, vitamin B6 and B12 supplements significantly reduce tHcy even in people who are not overtly vitamin deficient. If homocysteine is a causal risk factor for atherothrombotic events, treatment with B-vitamins might prove a simple and cost-effective means to reduce cardiovascular risk. However, it remains unclear whether elevated tHcy causes atherosclerosis or is simply a risk marker. To prove that homocysteine is a modifiable risk factor for cardiovascular disease it is necessary to show that lowering tHcy reduces vascular risk. The aim of this study was to determine whether long-term homocysteine-lowering with B-vitamins would improve vascular structure and function in people with a history of stroke. This study was a cross-sectional sub-study of the Vitamins TO Prevent Stroke trial (VITATOPS), a multi-centre, randomised, double-blind, placebo-controlled clinical trial designed to test the efficacy and safety of B-vitamins (folic acid 2mg, vitamin B6 25mg and vitamin B12 0.5mg) in the prevention of vascular events in patients with a recent history of stroke or transient ischemic attack. 173 VITATOPS participants were recruited for the current study. Age, sex, stroke type, medications, cardiovascular risk factors and smoking history were recorded and blood pressure, height, weight, waist and hip girth were measured in all subjects at least two years after randomisation. ... After a mean treatment period of 3.9 ± 0.9 years, the subjects randomised to vitamin treatment had significantly lower tHcy than the subjects randomised to placebo (7.9mol/L, 95%CI 7.5, 8.4 versus 11.8mol/L, 95%CI 10.9, 12.8; p<0.001). There were no significant differences between groups in CIMT (0.84 ± 0.17mm vitamins versus 0.83 ± 0.18mm placebo; p=0.74) or FMD (median of 4.0%, IQR 0.9, 7.2, vitamins versus 3.0%, IQR 0.6, 6.6 placebo; p=0.48). Pooled estimates from the meta-analyses showed that B-vitamin treatment reduces CIMT by 0.10mm (95%CI 0.20, -0.01mm) and increases FMD by 1.4%, (95%CI 0.7, 2.2), although these estimates may have been influenced by positive publication bias. The improvement in FMD was significant in studies of less than eight weeks duration but not in studies with longer treatment periods. The association between tHcy and CIMT and FMD was eliminated by adjustment for renal function and long-term B-vitamin treatment did not alter the strong linear relationship between tHcy and cystatin C. Lowering tHcy did not alter arterial wall inflammation assessed by 18FDG-PET, although small subject numbers meant we were unable to exclude a minor treatment effect. Long-term homocysteine-lowering with B-vitamin treatment did not improve CIMT or FMD or reduce arterial wall inflammation in people with a history of stroke. The relationship between tHcy and these markers of vascular risk was eliminated by adjustment for renal function. Our data are consistent with the hypothesis that elevated tHcy is a risk marker for cardiovascular disease rather than a modifiable causal risk factor.
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Showemimo, Opeyemi F. "Vitamin B12 Deficiency Does Not Stimulate Amyloid-beta Toxicity in a Ceanorhabditis elegans Model of Alzheimer’s Disease". Digital Commons @ East Tennessee State University, 2021. https://dc.etsu.edu/etd/3869.
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Alzheimer’s disease (AD) is symptomized by amyloid-beta plaques in the brain and accounts for more than 65 percent of dementia cases. Vitamin B12 (cobalamin) deficiency can result in similar cognitive impairment and roughly 15% of the elderly are vitamin B12 deficient. Vitamin B12 deficiency results in the accumulation of toxic methylmalonic acid and homocysteine. Hyperhomocysteinemia is a strong risk factor for AD. To test if vitamin B12 deficiency stimulates amyloid-beta toxicity, Caenorhabditis elegans expressing amyloid-beta in muscle were fed either vitamin B12-deficient OP50-1 or vitamin B12-rich HT115(DE3) E. coli bacteria. Increased amyloid-beta toxicity was found in worms fed the 0P50-1 diet. Supplementation of the OP50-1 diet with vitamin B12 did not rescue the increased C. elegans toxicity. Knockdown of either of the only two C. elegans vitamin B12-dependent enzymes metr-1 or mmmc-1 protected against toxicity. Therefore, vitamin B12 deficiency does not stimulate Alzheimer’s amyloid-beta-mediated toxicity in C. elegans.
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Brunaud, Laurent. "Déterminants nutritionnels et génétiques de l'homocystéine et méthylation de l'ADN : modèles expérimentaux et implications en pathologie". Nancy 1, 2003. https://hal.univ-lorraine.fr/tel-01746923.
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Shinohara, Elvira Maria Guerra. "Prevalência de anemia em gestantes de primeira consulta em centros de saúde do estado no Subdistrito de Paz do Butantã, Município de São Paulo". Universidade de São Paulo, 1989. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-27032008-142216/.
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Foram estudadas 363 gestantes de primeira consulta, que não faziam uso de medicamentos que continham ferro, ácido fólico, vitamina B12 ou associação destes, na ocasião da coleta do material, em Centros de Saúde do Estado, no Subdistrito de Paz do Butantã, município de São Paulo. A prevalência de anemia (concentração de hemoglobina inferior a 11,6 g/dl) foi de 12,4%. As médias das concentrações de hemoglobina e as prevalências de anemia, segundo o trimestre de gestação, foram respectivamente: 13,47 g/dl e 3,57% no primeiro, 12,47 g/dl e 20,86% no segundo e 12,25 g/dl e 32,14% no terceiro trimestre. Não encontramos diferença. estatisticamente significativa entre as médias das concentrações de hemoglobina e entre as prevalências de anemia nas gestantes primigestas e multigestas. O mesmo aconteceu com as médias e as prevalências das gestantes multigestas com intervalo do último parto até dois anos e maior que dois anos. Na amostra estudada, encontramos maior prevalência de anemia naquelas gestantes que pertenciam às famílias que tinham renda per capita até 0,5 SMPC (salário mínimo per capita). As prevalências de verminose e de ancilostomídeos nas 300 gestantes foram respectivamente: 64,7% e 14,0%. Nas gestantes anêmicas foram respectivamente: 73,7% e 7,9%. Nas gestantes anêmicas, a prevalência de deficiência de ferro foi de 42,2% (concentração de ferro sérico <50 µg/dl) ou 46,7% (saturação da transferrina <15% ou 40,0% (concentração de ferro sérico <50 µg/dl e saturação de transferrina <15%). A prevalência de deficiência de ácido fólico foi 44,4%. A prevalência de deficiência de ferro e ácido fólico foi de 17,8%. Não encontramos deficiência de vitamina B
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Barnabé, Aline 1982. "Prevalência das deficiências de ácido fólico, vitamina B12 e ferro em diversos grupos da população brasileira, após o programa de fortificação adotado pela ANVISA". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/312945.
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Orientadores: Nelci Fenalti Höehr, Joyce Maria Annichino-BizzacchiTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Folato, vitamina B12 e ferro são nutrientes essenciais, cujas deficiências afetam indivíduos em todas as faixas etárias, sendo consideradas um problema de Saúde Pública no mundo. Níveis reduzidos de folato e vitamina B12 podem estar associados com níveis elevados de homocisteína (Hcy), e que eventualmente resultam em complicações. Entretanto, no Brasil, poucos estudos avaliaram a prevalência dessas deficiências, principalmente de folato e vitamina B12, após a fortificação de farinhas com ácido fólico e ferro. Os objetivos do presente estudo foram: avaliar a prevalência das deficiências de folato, vitamina B12 e ferro em idosos, crianças, gestantes e lactantes após a fortificação de farinhas com ácido fólico e ferro adotado pela ANVISA em 2004; e investigar a contribuição de polimorfismos genéticos sobre os níveis de folato, vitamina B12 e Hcy nestes indivíduos. Os indivíduos foram recrutados em Centros de Saúde da cidade de Campinas entre 2006 a 2007. No total, 719 indivíduos incluindo, 262 idosos, 106 crianças, 291 gestantes e 60 lactantes foram incluídos. As concentrações destes nutrientes foram mensuradas por eletroquimioluminescência; a dosagem de Hcy foi realizada por cromatografia líquida de alta eficiência (CLAE); e os polimorfismos foram investigados por PCR-RFLP. Os resultados mostraram que a prevalência das deficiências de folato, vitamina B12 e ferro no grupo total de indivíduos foram de 0,3%, 5,3% e 12,6%, respectivamente. Praticamente não se observou a deficiência de folato, presente apenas em um idoso e uma gestante, enquanto que a deficiência de vitamina B12 foi prevalente em gestantes (8,9%) e idosos (4,2%). Além disso, a deficiência de ferro e anemia ferropriva foram prevalentes em crianças (9,9% e 4,9%, respectivamente), e gestantes (25,1% e 5,5%, respectivamente). A hiperhomocisteinemia esteve presente principalmente em idosos (34,3%). Com relação aos polimorfismos, apenas as gestantes carreadoras dos alelos CT+TT do polimorfismo no gene MTHFR (C677T) mostraram níveis reduzidos de folato (p=0,030). Através da análise múltipla, observamos que os níveis de Hcy foram determinados principalmente pelo folato (p<0,001), vitamina B12 (p<0,001), gênero (p<0,001) e idade (p<0,001) em idosos; vitamina B12 (p= 0,011) em crianças e folato (p=0,002) em gestantes. Nossos resultados demonstraram que na população avaliada, após 2 anos do início da fortificação de farinhas com ácido fólico e ferro, a deficiência de folato é praticamente inexistente, ao contrário da deficiência de ferro e de vitamina B12. A elevada prevalência da deficiência de vitamina B12 em idosos e gestantes deve ser valorizada na prática, devido ao risco de complicações. O mesmo deve ser observado em relação à deficiência de ferro, prevalente em crianças e gestantes. Portanto, medidas como suplementação e a dosagem desses nutrientes, para grupos populacionais de risco, devem ser implementados em políticas de Saúde Pública. Além disso, a hiperhomocisteinemia observada em idosos pode ser um fator de risco ou um marcador de doença arterial, que é comum nesses indivíduos
Abstract: Folate, vitamin B-12 and iron are essential nutrients, whose deficiencies are considerable public health problems worldwide, affecting all age groups. Low levels of folato and vitamin B12 have been associated with high concentrations of homocysteine (Hcy) and can lead to complications. In Brazil, a few studies evaluated the prevalence of these nutrients, especially, folate and vitamin B12, post acid folic and iron fortification era. The aim of this study was to assess folate, vitamin B12 and iron deficiencies in distinct Brazilian populations including elderly, children, pregnant and lactating women, after the initiation of folic acid and iron fortification by Brazilian authorities. We also investigated the contribution of polymorphisms on folate, vitamin B12 and Hcy levels in these individuals. Folate, vitamin B12 and ferritin levels were measured by chemiluminescence immunoassays, and Hcy levels were determined by high-performance liquid chromatography. Genotype analyses of RFC1 A80G, GCPII C1561T and MTHFR C677T polymorphisms were performed by PCR-RFLP. The individuals were recruited from primary care centers in Campinas ¿ Brazil, between 2006 - 2007. In total 719 individuals, including elderly (262), children (106), pregnant women (291) and lactating women (60) were included. The overall prevalence of low folate, vitamin B-12 and iron status was 0.3%, 5.3% and 12.6%, respectively. Folate deficiency was practically inexistent and was observed only in elderly (n=1) and pregnant women (n=1), whereas vitamin B12 deficiency was frequent in pregnant women (8.9%) and elderly (4.2%). Moreover, iron deficiency and iron deficiency anemia were prevalent in children (9.9% and 4.9%, respectively) and pregnant women (25.1% and 5.5%, respectively). Plasma Hcy concentrations were significantly higher in the elderly (34.3%). Pregnant women carrying the MTHFR 677T allele (CT+TT) showed lower serum folate levels (p=0.030), but none of the polymorphisms investigated in this study affected folate, vitamin B12 and Hcy levels in elderly, children and lactating women. After a multivariate analysis, Hcy levels were predicted by variables such as folate (p<0.001), vitamin B12 (p<0.001), gender (p<0.001) and age (p<0.001) in elderly; vitamin B12 (p= 0.011) in children; and folate (p = 0.002) in pregnant women. Our results demonstrated that folate deficiency is practically inexistent in this population, two years after the initiation of folic acid fortification, in contrast to vitamin B12 and iron deficiency. The high prevalence of vitamin B12 deficiency in elderly and pregnant women is relevant due to health complications. Supplementation and measure of nutrients in some groups of the population should be indicated by Public Health¿s policies. Furthermore, hiperhomocysteinemia in elderly can be a risk factor or a marker of arterial disease, which is common in these individuals
Doutorado
Ciencias Biomedicas
Doutora em Ciências Médicas
Libros sobre el tema "B12 vitamins"
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U, Gerbershagen H., Zimmermann M. 1933- y World Congress on Pain. (5th : 1987 : Hamburg, Germany), eds. B-vitamins in pain: Hamburg, 2nd August 1987. Frankfurt am Main: PMI Verlag, 1988.
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Food and Agriculture Organization of the United Nations. y World Health Organization, eds. Requirements of vitamin A, iron, folate, and vitamin B12: Report of a joint FAO/WHO expert consultation. Rome: Food and Agriculture Organization of the United Nations, 1988.
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Victor, Herbert, ed. Vitamin B12 deficiency. London: Royal Society of Medicine Press, 1999.
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Ruma, Banerjee, ed. Chemistry and biochemistry of B12. New York: Wiley, 1999.
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European Symposium on Vitamin B12 and B12-Proteins (4th 1996 Innsbruck, Austria). Vitamin B12 and B12-proteins: Lectures presented at the 4th European Symposium on Vitamin B12 and B12-Proteins. Weinheim: Wiley-VCH, 1998.
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1939-, Stroiński Andrzej, ed. Comprehensive B12: Chemistry, biochemistry, nutrition, ecology, medicine. Berlin: De Gruyter, 1987.
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Aloba, Oladapo Babatunde. Nutritional status of B6 vitamers, vitamin B12 and folate in alcoholic patients. [Guildford]: University of Surrey, 1999.
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International Symposium on Biomedicine and Physiology of Vitamin B12. (1st 1988 London, England). Biomedicine and physiology of vitamin B12: Proceedings of the First International Symposium, Charing Cross & Westminster Medical School, University of London, 26-29 September 1988. Editado por Bhatt H. R y Linnell J. C. London: The Children's Medical Charity, 1990.
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Waters, Henry McKiness. Vitamin B12: Absorption and binding proteins. Manchester: University of Manchester, 1996.
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1965-, Stuart Jeffrey J., ed. Could it be B12?: An epidemic of misdiagnoses. 2a ed. Fresno, Calif: Quill Driver Books, 2011.
Buscar texto completoCapítulos de libros sobre el tema "B12 vitamins"
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Marks, John. "Vitamin B12". En The Vitamins, 165–69. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-011-7321-6_26.
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Ball, G. F. M. "Vitamin B12". En Bioavailability and Analysis of Vitamins in Foods, 497–515. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4899-3414-7_14.
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Watanabe, Fumio y Yukinori Yabuta. "Microbiological Detection of Vitamin B12 and Other Vitamins". En Fortified Foods with Vitamins, 165–71. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527634156.ch13.
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Chen, Bo y Da-Jin Yang. "Analysis of Vitamin B12 by HPLC". En Fortified Foods with Vitamins, 155–64. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527634156.ch12.
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Spalla, C., A. Grein, L. Garofano y G. Ferni. "Microbial Production of Vitamin B12". En Biotechnology of Vitamins, Pigments and Growth Factors, 257–84. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-1111-6_15.
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Marie Sych, Janice, Christophe Lacroix y Marc J. A. Stevens. "Vitamin B12 - Physiology, Production and Application". En Industrial Biotechnology of Vitamins, Biopigments, and Antioxidants, 129–59. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2016. http://dx.doi.org/10.1002/9783527681754.ch6.
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Tappia, Paramjit S. y Naranjan S. Dhalla. "Role of Vitamin B12 in Cardiovascular Disease". En Hydrophilic Vitamins in Health and Disease, 253–68. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-55474-2_11.
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Jani, Gargi y Bhoomika Patel. "Association of Vitamin B12 with Bone Mineral Density". En Hydrophilic Vitamins in Health and Disease, 269–78. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-55474-2_12.
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Mikkelsen, Kathleen y Vasso Apostolopoulos. "Mechanistic Effects of Vitamin B6 and B12 on Inflammation and Cancer". En Hydrophilic Vitamins in Health and Disease, 279–308. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-55474-2_13.
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Bhargava, Seema y Mamta Kankra. "The Interweaving of B9- and B12-Dependent Reactions and Their Clinical Implications". En Hydrophilic Vitamins in Health and Disease, 309–23. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-55474-2_14.
Texto completoActas de conferencias sobre el tema "B12 vitamins"
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Alda, Liana Maria, Despina-Maria Bordean, Simion Alda, Diana Moigradean y Marcel Danci. "EVALUATION THE MINERAL CONTENT OF NORI SEAWEED, AVAILABLE ON THE ROMANIAN MARKET". En 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023/3.1/s15.45.
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Algae are some of the oldest forms of life on earth, being consumed for centuries. There are numerous studies that highlight the health benefits of consuming seaweed, due to the high content of proteins, dietary fibers, vitamins, antioxidants, and the low-fat content. Nori seaweeds, which is used in the preparation of sushi rolls, stands out for its low caloric intake and high content of minerals, vitamins (vitamin B12 and vitamin C), as well as iodine. Only certain types of species of seaweed are used to make Nori: Porphyra tenera, Porphyra yezoensis, Porphyra umbilicalis and Pyropia tenera (a newer name for Porphyra tenera, due to a taxonomic reclassification). In this work, we analyzed the mineral profile of some varieties of Nori algae available on the Romanian market, obtained in China and Japan. To determine the mineral content, we used X-Ray Fluorescence Analyzer (XRF). The results are expressed in mg/kg dry weight. The Nori dried seaweed recorded the highest values of potassium and calcium and the Nori roasted seaweed the highest iron and zinc contents. Our experimental results recommend the consumption of Nori algae, in order to cover the daily requirement of minerals.
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"The study of relationship between vitamins B12, B6 and folic acid with homocysteine blood levels in cardiovascular patients". En International Conference on Medicine, Public Health and Biological Sciences. CASRP Publishing Company, Ltd. Uk, 2016. http://dx.doi.org/10.18869/mphbs.2016.153.
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LÓPEZ, MARÍA ASCENSIÓN. "Déficit de vitamina B12". En XXIX Congreso Nacional de Medicina General y de Familia y V Jornadas SEMG Andalucía. Grupo Pacífico, 2023. http://dx.doi.org/10.48158/semg23-253.
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ARAUJO, RAQUEL PESSOA DE, ANDRECIANA GOMES DE SOUSA, ANNA LYGIA PEREIRA BENEVIDES y ANA LUIZA DE REZENDE FERREIRA MENDES. "MICRONUTRIENTES RELACIONADOS A ESTÉTICA EM PACIENTES QUE REALIZARAM CIRURGIA BARIÁTRICA". En Brazilian Congress. brazco, 2020. http://dx.doi.org/10.51162/brc.health2020-00028.
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Pode-se observar uma carencia de vitaminas e minerais frequente em pacientes que realizaram bariatrica, ocasionada pela restricao do duodeno e jejuno como tambem ao contato limitado do alimento. Objetivo: Analisar a deficiencia de micronutrientes relacionados a estetica em mulheres que realizaram cirurgia bariatrica e metabolica em uma clinica que tem como foco o tratamento cirurgico da obesidade. Metodos: A pesquisa realizada em 2019 teve carater quantitativo e descritivo, a amostra foi composta por 21 mulheres que ja realizaram cirurgia bariatrica com prontuarios que continham niveis sericos de zinco, ferro, ferritina, vitamina D e B12 e apresentaram sinais clinicos de queda de cabelo, tontura e fraqueza. Resultados: Foram analisados 21 prontuarios de mulheres que realizaram a cirurgia. No pre operatorio, 95,23% ja apresentavam deficiencia de micronutrientes, sendo a vitamina D em maior prevalencia. No pos operatorio, o mesmo numero de mulheres continuaram apresentando deficiencias sendo 52,38% vitamina D, o zinco com 19,04%, vitamina B12 e ferritina 9,52%. Conclusao: O acompanhamento nutricional antes mesmo da cirurgia, bem como a longo prazo juntamente com a suplementacao de vitaminas e necessaria e essencial para prevenir essas deficiencias. A maioria das mulheres analisadas referem queda de cabelo, tontura e fraqueza. A deficiencia de micronutrientes nesses pacientes pode desencadear um desequilibrio no organismo por serem essenciais em varios processos metabolicos, bem como afetar a auto estima por isso um acompanhamento nutricional e recomendado antes, durante e depois da cirurgia.,
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Melo, Yasmim Stephane Lima y Henrique Fonseca Sousa do Nascimento. "RELAÇÃO ENTRE NUTRIÇÃO E SISTEMA IMUNOLÓGICO: REVISÃO DE LITERATURA". En I Congresso Brasileiro de Saúde Pública On-line: Uma abordagem Multiprofissional. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/3054.
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Introdução: Alguns nutrientes podem interferir nas respostas imunes devido a seus efeitos regulatórios sobre os glóbulos brancos como diferenciação, proliferação e produção de citocinas, devido a isso a carência desses nutrientes compromete o desempenho do sistema imunológico no combate a infecções. Objetivo: Descrever de que maneira os nutrientes atuam no desempenho do sistema imunológico. Materiais e Métodos: Trata-se de uma revisão de literatura. A pesquisa da literatura foi realizada nas bases de dados SCIELO e PUBMED selecionando artigos na língua portuguesa publicados entre os anos de 2010 a 2021. Resultados: De acordo com os artigos avaliados, os minerais e as vitaminas tem papel fundamental nas respostas imunes visto que o ferro estimula a produção de linfócitos T auxiliares e sua carência reduz a capacidade fagocitária dos neutrófilos e o número de linfócitos T; o Magnésio atua nas funções dos linfócitos T e B e a deficiência desse mineral interfere na fagocitose e na produção de citocinas pelas células; o zinco estimula a proliferação de linfócitos T e sua baixa concentração no organismo provoca o aumento do número de células CD8 e redução do número de células CD4, monócitos e neutrófilos e a redução da atividade das células Natural Killers; a vitamina A atua na estabilidade das células e tecidos que fazem parte do sistema imune e sua carência deixa o organismo suscetível a infecções; a vitamina D auxilia na diferenciação e regulação das células efetoras; a vitamina E pode aumentar a produção de imunoglobulinas; a vitamina C atua no crescimento e diferenciação das células, na produção de anticorpos, migração celular e aumento da resistência do organismo contra infecções virais. As vitaminas do complexo B atuam, sobretudo, no aumento do número de linfócitos T circulantes, porém, as vitaminas B2 (Riboflavina) e B5 (Ácido Pantotênico) também atuam na melhora da reposta humoral e a vitamina B12 (Cianocobalamina) na melhora da atividade fagocitária. Conclusão: Conclui-se que as respostas imunes são reguladas pelo quadro nutricional do organismo, por essa razão a alimentação balanceada é importante para manter um pleno funcionamento do sistema imunológico e proteger o corpo contra possíveis infecções.
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Ramalho, Daniel Avila y Letícia Mello Matos. "CONSEQUÊNCIAS DA INGESTÃO DEFICITÁRIA DA VITAMINA B12 NO TECIDO HEMATOPOIÉTICO". En I Congresso On-line Nacional de Histologia e Embriologia Humana. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/2710.
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Introdução: Também conhecida como Cobalamina, a vitamina B12 desempenha atividades indispensáveis no corpo, como manutenção da cognição e prevenção à degeneração celular de células nervosas. Sobre a conformidade entre o tecido hematopoiético e a Cobalamina, o papel da vitamina B12 refere-se à produção eritrocitária e manutenção dos níveis férricos do organismo, agindo, portanto, na prevenção contra patologias como anemias. Objetivo: Essa revisão de literatura tem por objetivo elucidar danos decorrentes da ingestão deficitária da Cobalamina no tecido hematopoiético. Material e métodos: Trata-se de uma revisão bibliográfica acerca dos efeitos da ingestão deficitária da vitamina B12 no tecido hematopoiético. Pesquisou-se nas bases de dados PubMed e Scielo os termos: “vitamina B12”, “tecido hematopoiético” e “ingestão da vitamina B12”, além dos respectivos em inglês. Resultados: A deficiência de vitamina B12 leva a diversos transtornos hematológicos, neurológicos e cardiovasculares. Isso se deve à sua interferência no metabolismo de homocisteína, aminoácido presente no plasma sanguíneo, e nas reações de metilação do organismo, importantes para a regulação da expressão gênica e, consequentemente, diferenciação celular e formação tecidual. Tais interferências são importantes para o funcionamento adequado do tecido hematopoiético, essencial para a produção dos eritrócitos, cuja deficiência leva a transtornos hematológicos. As principais hemopatologias relacionadas à ingestão defasada de Cobalamina, por sua vez, são as anemias megaloblásticas, cuja sintomatologia engloba fraqueza, palidez, cefaleia e irritabilidade. O tratamento dessas anemias consiste em injeções de vitamina B12 e ácido fólico, necessárias para o funcionamento do tecido hematopoiético, e na suplementação de vitamina C, importante para a absorção de ferro. Portanto, é necessária alimentação rica em Cobalamina, cujos alimentos com maiores concentrações são de origem animal. Vale ressaltar que é essencial àqueles que fazem dietas vegetarianas ou veganas a suplementação dessa vitamina ou a ingestão de levedura nutricional, única fonte de vitamina B12 que não é de origem animal. Conclusão: Assim, a ingestão de vitamina B12 é importante para o organismo visto que sua deficiência leva a diversos transtornos graves que dificultam a manutenção da vida. Logo, abordagem clínica e diagnóstica, além de detalhes terapêuticos e suplementação cobalamínica, são indispensáveis para a garantia da qualidade de vida da população.
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MONTAÑO, LAURA, FRANCISCO PIEDRA y GEMA ESPERANZA RUIZ. "Déficit de vitamina B12 con trastorno neurológico". En XXIX Congreso Nacional de Medicina General y de Familia y V Jornadas SEMG Andalucía. Grupo Pacífico, 2023. http://dx.doi.org/10.48158/semg23-55.
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Feofilaktova, O. V. "STUDY OF THE STORAGE OF BAS ENCAPSULATED IN EMULSION FOOD SYSTEMS". En I International Congress “The Latest Achievements of Medicine, Healthcare, and Health-Saving Technologies”. Kemerovo State University, 2023. http://dx.doi.org/10.21603/-i-ic-137.
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The article presents the results of a comparative analysis of the persistence of biologically
active substances on the example of vitamins B1 and E, encapsulated in the matrix core of double
emulsion food systems, in the aqueous phase of the direct and fatty phase of the reverse emulsion
food systems. According to the results of the research, the efficiency of vitamin encapsulation in
double emulsion systems was established to increase their shelf life: at the end of storage, the residual content of vitamin B1 in the double emulsion system water-oil-water was 34% higher than
its content in the inverse emulsion, and the content of vitamin E in the emulsion system oil-wateroil at the end of the storage period was 24% more than in direct emulsion.
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Dohrn, W., A. Schweers, H. Rietema, M. Lorentschk y A. Klimkiewicz. "Vitamin B12-Mangel induzierte Panzytopenie als Weaninghindernis". En 63. Kongress der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin e. V. Georg Thieme Verlag, 2023. http://dx.doi.org/10.1055/s-0043-1760994.
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Vasyukova, A. T., D. A. Tikhonov, R. A. Edwards, M. V. Vasyukov y Talbi Mounir. "Macro- and microelements in new products for the population of ecological territories at risk". En III All-Russian Scientific Conference with International Participation "Science, technology, society: Environmental engineering for sustainable development of territories". Krasnoyarsk Science and Technology City Hall, 2022. http://dx.doi.org/10.47813/nto.3.2022.6.617-621.
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Reduction of deficiency of macro- and microelements in foodstuffs (in particular, iodine and fluorine) of ecologically impoverished regions is possible in the development of new products. In this regard, dietary supplements have been introduced into the recipes of meat, fish, vegetable, cereal and curd dishes. The combination of the main raw materials and additives, the functional properties of the products have been studied, and the optimal organoleptic, structural-mechanical, and rheological properties have been established. Additive "Mobi-lux Universal", containing heme iron, organic calcium and iodine, enrich a wide group of products with minerals by creating protein-vegetable combined compositions. Recipes have been developed and technologies have been substantiated for “Morskie” fish cakes, “Pikantny” meat steak, “Raduzhny” fruit and curd dessert, fruit mousses, and “Appetitnaya” rice casserole with apples. The results of a study of the nutritional value of specialized food products based on meat, fish, vegetable, fruit, cereal products and cottage cheese, enriched with the Mobi-lux Universal complex functional additive, vegetable and fruit powders, are presented. More than 20 dishes have been developed and included in corrective diets for schoolchildren. It has been established that the maximum enrichment of meat and fish products is carried out with vitamins: Betacarotene, B6, B12, as well as macro- and microelements: iron, iodine, calcium, sodium, magnesium and fluorine. Protein-containing fish and meat dishes, due to the included additive, make up for 15% of the daily deficiency in these nutrients (iodine, calcium and iron). Dessert, mousse and casserole - to dishes-sources of bio-organic iodine, calcium and iron. This will fully balance the diet of students in the category of 7-11 years old. The developed dishes were tested in the production conditions of catering establishments of educational organizations.
Informes sobre el tema "B12 vitamins"
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Singh, Ruchi, Akhiya Nail y Nirendra Kumar Rai. Effectiveness of Vitamin B12 Supplementation on cognitive, motor & mood instability of Parkinson’s disease patients on levodopa treatment :A Systematic review. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, febrero de 2023. http://dx.doi.org/10.37766/inplasy2023.2.0066.
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Review question / Objective: The treatment of choice for patients of Parkinson's disease is levodopa. However, levodopa has been suggested to decrease Vit B12 level in these patients. Thus, the research question for this systematic review is whether vit B 12 supplementation in Parkinson's disease(PD) patients on treatment with levodopa improves vit B12 level effecting the Cognition, Motor functions and Mood instability among them in comparison to PD patients on levodopa treatment who are not supplemented with Vit B12. Condition being studied: Parkinson disease is the progressive degeneration of dopaminergic neurons present within the substantia nigra that can lead to altered movements along with the prevalence of cognitive and mood instability as a result of dopamine(neurotransmitter) deficiency. The most effective treatment for the Parkinson's disease is the administration of levodopa, a dopamine precursor . Long term treatment with levodopa causes an increase in homocysteine levels and tissue deficiency of vitamin B12 and folate may occur. Vitamin B12 supplementation is administered as after management regime, in Parkinson patient on levodopa treatment . This study aims to conduct a systematic review, of studies , randomized control trials investigating the ability of vitamin B12 supplementation to enhances the recovery/reduce the decline, if any, of the symptoms of cognitive, motor, mood impairments associated with Parkinson's disease patient on levodopa treatment.
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Lekhanya, Portia Keabetswe y Kabelo Mokgalaboni. Exploring the effectiveness of vitamin B12 complex and alpha-lipoic acid as a treatment for diabetic neuropathy. Protocol for systematic review. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, mayo de 2022. http://dx.doi.org/10.37766/inplasy2022.5.0167.
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Review question / Objective: Does Alpha-Lipoic acid increase the uptake of glucose for better glycaemic control? Does vitamin B12 and Alpha-Lipoic acid improve inflammation? The aim of the study is to explore the effectiveness of Vitamin B12 and Alpha-Lipoic Acid as a possible treatment for diabetic neuropathy with major emphasis on markers of inflammation and glucose metabolism. Condition being studied: Diabetic Neuropathy (DN) is a heterogeneous type of nerve damage associated with diabetes mellitus, the condition most often damages nerves in the legs and feet. It presents both clinically and sub-clinically affecting the peripheral nervous system as a result of an increase in glucose concentration which interferes with nerve signalling. After the discovery of insulin as a treatment for Diabetes Mellitus (DM), the prevalence of DN has since increased significantly due to DM patients having a longer life expectancy. It has been estimated that atleast 50% of DM patients will develop DN in their life, with approximately 20% of these patients experiencing neuropathic pain. Nerves are susceptible to changes in glucose concentrations and insulin makes it impossible for neurons to continue regulating glucose uptake.
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Liu, Yiti, Maoyuan Gou y Xiaoyan Guo. Features of plasma homocysteine, vitamin B12, and folate in Parkinson’s disease: An updated meta-analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, abril de 2023. http://dx.doi.org/10.37766/inplasy2023.4.0099.
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Liu, Kefeng, Zhirong Yang, Wang Miao, Bang Zheng, Shanshan Wu, Shuzhang Du, Xiaojian Zhang, Yang Zhao, Shusen Sun y Jie Zhao. Vitamin B12 levels and risk of all-cause, cardiovascular disease and cancer mortality: a systematic review and dose-response meta-analysis of cohort studies. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, mayo de 2022. http://dx.doi.org/10.37766/inplasy2022.5.0129.
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Rouseff, Russell L. y Michael Naim. Characterization of Unidentified Potent Flavor Changes during Processing and Storage of Orange and Grapefruit Juices. United States Department of Agriculture, septiembre de 2002. http://dx.doi.org/10.32747/2002.7585191.bard.
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Citrus juice flavor quality traditionally diminishes after thermal processing and continuously during storage. Our prior studies found that four of the five most potent off-aromas formed during orange juice storage had not been identified. The primary emphasis of this project was to characterize and identify those potent flavor degrading aroma volatiles so that methods to control them could be developed and final flavor quality improved. Our original objectives included: 1 Isolate and characterize the most important unidentified aroma impact compounds formed or lost during pasteurization and storage. 2. Determination of thiamine and carotenoid thermal decomposition and Strecker degradation pathways in model solutions as possible precursors for the unidentified off-flavors. 3. Evaluate the effectiveness of an "electronic nose" to differentiate the headspace aromas of from untreated and heat pasteurized orange and grapefruit juices. 4. Use model systems of citrus juices to investigate the three possible precursor pathways (from 2) for flavor impact compounds formed or lost during pasteurization or storage. RESULTS - The components responsible for citrus storage off flavors and their putative precursors have now been identified. Certain carotenoids (b-carotene) can thermally degrade to produce b-ionone and b-damascenone which are floral and tobacco smelling respectively. Our GC-O and sensory experiments indicated that b-damascenone is a potential storage off-flavor in orange juice. Thiamine (Vitamin B1) degradation produces 2-methyl-3-furan thiol, MFT, and its dimer bis(2- methyl-3-furyl) disulfide which both produce meaty, savory aromas. GC-O and sensory studies indicated that MFT is another storage off-flavor. Methional (potato aroma) is another off flavor produced primarily from the reaction of the native amino acid, methionine, and oxidized ascorbic acid (vitamin C). This is a newly discovered pathway for the production of methional and is more dominant in juices than the classic Maillard reaction. These newly identified off flavors diminish the flavor quality of citrus juices as they distort the flavor balance and introduce non-typical aromas to the juice flavor profile. In addition, we have demonstrated that some of the poor flavor quality citrus juice found in the market place is not only from the production of these and other off flavors but also due to the absence of desirable flavor components including several potent aldehydes and a few esters. The absence of these compounds appears to be due to incomplete flavor volatile restoration after the making of juice concentrates. We are the first to demonstrate that not all flavor volatiles are removed along with water in the production of juice concentrate. In the case of grapefruit juice we have documented which flavor volatiles are completely removed, which are partially removed and which actually increase because of the thermal process. Since more that half of all citrus juices is made into concentrate, this information will allow producers to more accurately restore the original flavor components and produce a juice with a more natural flavor. IMPLICATIONS - We have shown that the aroma of citrus juices is controlled by only 1-2% of the total volatiles. The vast majority of other volatiles have little to no direct aroma activity. The critical volatiles have now been identified. The ability to produce high quality citrus juices requires that manufacturers know which chemical components control aroma and flavor. In addition to identifying the critical flavor components (both positive and negative), we have also identified several precursors. The behavior of these key aroma compounds and their precursors during common manufacturing and storage conditions has been documented so manufacturers in Israel and the US can alter production practices to minimize the negative ones and maximize the positive ones.
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Depressed young people have lower vitamin B12 and vitamin D levels than their peers. ACAMH, agosto de 2020. http://dx.doi.org/10.13056/acamh.12905.
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