Cross sectional study of vitamin B12 supplementation in Slovak and Czech vegans.

Background: The number of vegans in the world is growing and in Slovakia and the Czech Republic they make up 1% of the population. Vegan diet excludes all foods of animal origin and vegans who do not use vitamin B12 supplements are at risk of the vitamin B12 deficiency. Objective: The aim of this study was to determine what proportion of Czech and Slovak vegans use vitamin B12 supplements regularly, irregularly or not at all and what is their supplemental cobalamin intake. Materials and methods: The research involved 1337 self-identified vegans from Slovakia and the Czech Republic who were interviewed using the CAWI (Computer-Assisted Web Interview) method. Participants were recruited by posts in veganism-themed social media groups. Results: Out of 1337 vegans 55.5% supplemented cobalamin regularly, 32.54% irregularly and 11.97% were not supplementing. Rate of not supplementing individuals was 5.04% higher in Slovaks than in Czechs. Short-term vegans had a significantly higher rate of not supplementing individuals (17.99%) compared to medium-term (8.37%) and long-term vegans (7.50%). Mean weekly cobalamin intake from supplements was 2938.34±2566.60 µg in regularly supplementing vegans compared to 1630.31±1949.27 µg in irregularly supplementing vegans, particularly due to the lower weekly supplementation frequency among irregularly (2.93) compared to regularly supplementing vegans (5.27). Conclusions: The rate of supplementation in Slovak and particularly Czech vegans was higher than in other countries. The number of not supplementing individuals was significantly higher among short-term vegans, indicating that there is still a need for education on the importance of adequate and regular cobalamin supplementation, especially in new vegans. Our results support the hypothesis that the reason for higher rate of cobalamin deficiency in irregularly compared to regularly supplementing vegans is the lower cobalamin intake caused by lower supplementation frequency.

Association of dietary intakes of vitamin B12, vitamin B6, folate, and methionine with the risk of esophageal cancer: the Japan Public Health Center-based (JPHC) prospective study.

BACKGROUND: B vitamins and methionine are essential substrates in the one-carbon metabolism pathway involved in DNA synthesis and methylation. They may have essential roles in cancer development. We aimed to evaluate the associations of dietary intakes of vitamin B12, vitamin B6, folate, and methionine with the risk of esophageal cancer (EC) using data from the Japan Public Health Center-based Prospective Study. METHODS: We included 87,053 Japanese individuals who completed a food frequency questionnaire and were followed up from 1995-1998 to 2013 and 2015. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by Cox proportional-hazard regression across quintiles of dietary intakes of B vitamins and methionine. RESULTS: After 1,456,678 person-years of follow-up, 427 EC cases were documented. The multivariable HR (95% CI) of incident EC in the highest versus lowest quintile of dietary intake of vitamin B12 was 1.75 (1.13-2.71; p-trend=0.01). Stratification analysis based on alcohol consumption showed that higher dietary intakes of vitamin B12 and methionine were associated with an increased risk of EC among never-drinkers; HRs (95% CIs) were 2.82 (1.18-6.74; p-trend=0.009; p-interaction=0.18) and 3.45 (1.32-9.06; p-trend=0.003; p-interaction 0.02) for vitamin B12 and methionine, respectively. Meanwhile, there was no association between vitamin B12 and methionine intake with the risk of EC among drinkers. There were no associations between dietary intake of folate or vitamin B6 and the risk of EC. CONCLUSION: Dietary intake of vitamin B12 was positively associated with the risk of EC in the Japanese population.

Prevalence of vitamin B12 deficiency in healthy Indian school-going adolescents from rural and urban localities and its relationship with various anthropometric indices: a cross-sectional study.

BACKGROUND: Micronutrient deficiency is a global health burden, especially among developing countries. The present cross-sectional study aimed to determine the prevalence of vitamin B12 deficiency in healthy Indian school-going adolescents, based on area of residence, sex and body mass index (BMI). Furthermore, the relationship of serum B12 concentration with dietary vitamin B12 intake and anthropometric indices was assessed among adolescents from rural and urban India. METHODS: A total of 2403 school-going adolescents (11-17 years) from National Capital Region and rural areas of Haryana, India were selected. Serum B12 concentrations were estimated using an electrochemiluminescence immunoassay. Dietary assessments were conducted on 65% of total participants (n = 1556) by two 24-h diet recalls. RESULTS: The prevalence of vitamin B12 deficiency in the total study population was 32.4% (rural: 43.9% versus urban: 30.1%, P < 0.001; male: 34.4% versus female: 31.0%, P < 0.05; normal weight: 28.1%, versus overweight: 39.8%, versus obese: 51.2%, P < 0.001). More than half (51.2%) of obese adolescents were vitamin B12 deficient. On multiple linear regression analysis, serum B12 in rural adolescents was associated with age (ß = -0.12, P < 0.05). Among urban adolescents, serum B12 was associated with BMI (ß = -0.08, P < 0.05) and adjusted dietary vitamin B12 intake (ß = 0.14, P < 0.001). Serum vitamin B12 levels were found to be lower in rural females (ß = -0.12, P = 0.030) and urban males (ß: 0.11, P < 0.001) compared to their respective contemporaries. CONCLUSIONS: Vitamin B12 deficiency was higher among rural school-going adolescents. Boys had a higher B12 deficiency than girls. Inverse associations of serum B12 with adiposity indices were observed. Serum B12 levels were positively associated with dietary vitamin B12 intake.

Association of B vitamin intake and total homocysteine levels with all-cause and cause-specific mortality in central obesity.

OBJECTIVES: Future primary prevention strategies may benefit from understanding the connection between mortality in individuals with central obesity and modifiable lifestyle factors like dietary intake. This study sought to determine whether there was a separate relationship between folate, vitamin B6, and vitamin B12 intake and all-cause and cause-specific mortality in the US population with central obesity. METHODS: The study analyzed data from the National Health and Nutrition Examination Survey between 1999 and 2016. Using the Cox proportional hazards model, the association between dietary intake of B vitamins and all-cause and cause-specific mortality was examined. A total of 7718 adults with central obesity were enrolled, with a mean age of 49.87 (SD = 0.25) y at baseline. RESULTS: Folate intake was independently associated with a decreased incidence of all-cause mortality (adjusted hazard ratio = 0.71; 95% CI, 0.58-0.87). Furthermore, higher intake of vitamin B6 and vitamin B12 was inversely correlated with cardiovascular disease mortality (adjusted hazard ratio = 0.63; 95% CI, 0.40-0.98; and adjusted hazard ratio = 0.44; 95% CI, 0.29-0.65, respectively) and the finding reveal an interaction between homocysteine and vitamin B12 and folate on All-cause mortality CONCLUSIONS: The findings of this study suggest that vitamin B12 and folate intake may be protective factors in individuals with central obesity. It is important to consider both their total homocysteine level and body mass index in conjunction with these nutrients. Further research is needed to validate these findings.

Elevated Plasma Vitamin B12 in Patients with Hepatic Glycogen Storage Diseases.

Background: Hepatic glycogen storage diseases (GSDs) are inborn errors of metabolism affecting the synthesis or breakdown of glycogen in the liver. This study, for the first time, systematically assessed vitamin B12 status in a large cohort of hepatic GSD patients. Methods: Plasma vitamin B12, total plasma homocysteine (tHcy) and methylmalonic acid concentrations were measured in 44 patients with hepatic GSDs and compared to 42 healthy age- and gender-matched controls. Correlations of vitamin B12 status with different disease markers of GSDs (including liver transaminase activities and triglycerides) as well as the vitamin B12 intake were studied. Results: GSD patients had significantly higher plasma vitamin B12 concentrations than healthy controls (p = 0.0002). Plasma vitamin B12 concentration remained elevated in GSD patients irrespective of vitamin B12 intake. Plasma vitamin B12 concentrations correlated negatively with triglyceride levels, whereas no correlations were detected with liver transaminase activities (GOT and GPT) in GSD patients. Merging biomarker data of healthy controls and GSD patients showed a positive correlation between vitamin B12 status and liver function, which suggests complex biomarker associations. A combined analysis of biomarkers permitted a reliable clustering of healthy controls versus GSD patients. Conclusions: Elevated plasma concentration of vitamin B12 (irrespective of B12 intake) is a common finding in patients with hepatic GSD. The negative correlation of plasma vitamin B12 with triglyceride levels suggests an influence of metabolic control on the vitamin B12 status of GSD patients. Elevated vitamin B12 was not correlated with GOT and GPT in our cohort of GSD patients. Merging of data from healthy controls and GSD patients yielded positive correlations between these biomarkers. This apparent dichotomy highlights the intrinsic complexity of biomarker associations and argues against generalizations of liver disease and elevated vitamin B12 in blood. Further studies are needed to determine whether the identified associations are causal or coincidental, and the possible impact of chronically elevated vitamin B12 on GSD.

Associations of Circulating Methylmalonic Acid and Vitamin B-12 Biomarkers Are Modified by Vegan Dietary Pattern in Adult and Elderly Participants of the Adventist Health Study 2 Calibration Study.

BACKGROUND: Elevated plasma methylmalonic acid (MMA) is a functional biomarker of vitamin B-12 status but limited information is available on its prevalence in US vegetarians. OBJECTIVES: The study examines the prevalence of plasma MMA ≥0.27 µmol/L in those consuming vegetarian diets, its associations with vitamin B-12 intake and biomarkers, and the modifying effect of vegetarian patterns on these associations. METHODS: In this cross-sectional study (n = 785), concentrations of MMA, vitamin B-12, holotranscobalamin (holoTC), and homocysteine (Hcy) were determined in participants of the calibration substudy of the Adventist Health Study 2 (AHS-2). Vitamin B-12 intake from food, fortified food, and supplements was assessed by six 24-h recalls. Regression models were used to estimate ORs of having high MMA as related to vitamin B-12 status biomarkers, vitamin B-12 intake, and dietary pattern. RESULTS: The prevalence of low vitamin B-12 status defined by serum vitamin B-12 <148 pmol/L, holoTC <35 pmol/L, MMA ≥0.27 and ≥0.37 µmol/L, or Hcy ≥15 µmol/L, and the OR of having high MMA did not differ by dietary pattern, possibly due to intake from fortified food and supplements. Total daily vitamin B-12 intake in the second tertile range of 4.4-14.5 µg/d reduced the likelihood of elevated MMA by 69%; and a doubling of vitamin B-12 intake was associated with a 4.3% decrease in plasma MMA. The association between log plasma MMA and biomarkers was modified by diet, with the vegan pattern showing an ∼3-fold stronger association with log serum vitamin B-12 and Hcy than did the nonvegetarian pattern. CONCLUSIONS: The prevalence of vitamin B-12 intake <2.0 µg/d was 15.2% in vegans, 10.6% in lacto-ovo-vegetarians, and 6.5% in nonvegetarians. Given the irreversible neurological consequences of vitamin B-12 inadequacy, the importance of regular supplemental vitamin B-12 intake in adult and elderly individuals is stressed.

One-half of Korean adults studied had marginal vitamin B12 status assessed by plasma vitamin B12.

Information is limited on the current vitamin B12 status of South Koreans, including the results of biochemical indices. The objective of this study was to assess vitamin B12 status with vitamin B12 intake, major food sources, and plasma vitamin B12 concentration in Korean adults. We hypothesized that vitamin B12 intake and status would be different between sex and age groups. Three consecutive 24-hour recalls and fasting blood samples were obtained from healthy 20- to 64-year-old adults (N=141). The dietary vitamin B12 intake of the men (10.77±6.11 µg/d) was significantly higher than that of the women (7.93±5.01 µg/d). The mean dietary vitamin B12 intake was significantly lower in the subjects aged 20-29 years than in the subjects aged 50-64 years. Only 2.1% of the subjects consumed less vitamin B12 than the estimated average requirement for Koreans. The top 4 major food sources of vitamin B12 were seafood, which provided 35.36% of the dietary vitamin B12 intake. There was no significant difference in plasma vitamin B12 concentration between sex and among age groups. Approximately 17% of total subjects had a plasma vitamin B12 concentration <125 pmol/L, indicating vitamin B12 deficiency, and 36.2% had marginal vitamin B12 status (125 to <250 pmol/L). The reported vitamin B12 intake was affected by both sex and age. However, plasma vitamin B12 concentration did not differ between sex and among age groups. One-half of the subjects had marginal vitamin B12 status using plasma vitamin B12.

Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study.

Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between dietary sources of vitamin B-12 (meat, fish and shellfish, eggs, dairy) and serum vitamin B-12, using cross-sectional data of 600 Dutch community-dwelling adults (≥65 years). Dietary intake was assessed with a validated food frequency questionnaire. Vitamin B-12 concentrations were measured in serum. Associations were studied over tertiles of vitamin B-12 intake using P for trend, by calculating prevalence ratios (PRs), and splines. Whereas men had significantly higher vitamin B-12 intakes than women (median (25th-75th percentile): 4.18 (3.29-5.38) versus 3.47 (2.64-4.40) µg/day), serum vitamin B-12 did not differ between the two sexes (mean ± standard deviation (SD): 275 ± 104 pmol/L versus 290 ± 113 pmol/L). Higher intakes of dairy, meat, and fish and shellfish were significantly associated with higher serum vitamin B-12 concentrations, where meat and dairy-predominantly milk were the most potent sources. Egg intake did not significantly contribute to higher serum vitamin B-12 concentrations. Thus, dairy and meat were the most important contributors to serum vitamin B-12, followed by fish and shellfish.