Vegetarians are at risk for vitamin B(12) (B12) deficiency due to suboptimal intake. The goal of the present literature review was to assess the rate of B12 depletion and deficiency among vegetarians and vegans. Using a PubMed search to identify relevant publications, 18 articles were found that reported B12 deficiency rates from studies that identified deficiency by measuring methylmalonic acid, holo-transcobalamin II, or both. The deficiency rates reported for specific populations were as follows: 62% among pregnant women, between 25% and almost 86% among children, 21-41% among adolescents, and 11-90% among the elderly. Higher rates of deficiency were reported among vegans compared with vegetarians and among individuals who had adhered to a vegetarian diet since birth compared with those who had adopted such a diet later in life. The main finding of this review is that vegetarians develop B12 depletion or deficiency regardless of demographic characteristics, place of residency, age, or type of vegetarian diet. Vegetarians should thus take preventive measures to ensure adequate intake of this vitamin, including regular consumption of supplements containing B12.

This study used an experimental, pretest-posttest control group repeated measures design to evaluate the effectiveness of a community-based culturally appropriate lifestyle intervention program to reduce the risk for type 2 diabetes (T2DM) among Gujarati Asian Indians (AIs) in an urban community in the US. Participants included 70 adult AIs in the greater Houston metropolitan area. The primary outcomes were reduction in weight and hemoglobin A1c (HbA1c) and improvement in physical activity. Participants were screened for risk factors and randomly assigned to a 12-week group-based lifestyle intervention program (n = 34) or a control group (n = 36) that received standard print material on diabetes prevention. Participants also completed clinical measures and self-reported questionnaires about physical activity, social, and lifestyle habits at 0, 3, and 6 months. No significant baseline differences were noted between groups. While a significant decline in weight and increase in physical activity was observed in all participants, the intervention group lowered their HbA1c (p < 0.0005) and waist circumference (p = 0.04) significantly as compared to the control group. Findings demonstrated that participation in a culturally tailored, lifestyle intervention program in a community setting can effectively reduce weight, waist circumference, and HbA1c among Gujarati AIs living in the US.

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Vitamin B 12 (B 12 ) is essential in activating folate needed in DNA synthesis. Inadequate intake results in the impairment of nerve transmission and inadequate synthesis of erythrocytes and other hematological cells. Two separate mechanisms of B 12 absorption exist, a receptor-mediated endocytosis that occurs in the distal ileum and the mass-action pharmacologic mechanism. The recommended dietary allowance for B 12 for adults issued by the Institute of Medicine is 2.4 µg/d. B 12 is only found in meats and other foods of animal origin. B 12 deficiency is widespread. Two main causes of deficiency include inadequate absorption and intake. Elderly and vegetarians are at highest risk for deficiency. Prevalence of deficiency ranges from 7% of the US population 3 years and older to 90% among vegans. The best way to assess deficiency is by using methylmalonic acid. Populations at risk could benefit from using B 12 supplements and from fortification of flour.