How prevalent is vitamin B(12)  deficiency among vegetarians?
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.
Department of Nutrition Science, East Carolina University, Greenville, NC 27858, USA. pawlakr@ecu.edu
Roman
R
Pawlak
Scott James
SJ
Parrott
Sudha
S
Raj
Diana
D
Cullum-Dugan
Debbie
D
Lucus
D000293:Adolescent; D000328:Adult; D014676:Diet, Vegetarian / Q000009:adverse effects*; D005260:Female; D005492:Folic Acid / Q000097:blood; D006801:Humans; D009751:Nutritional Requirements; D011247:Pregnancy; D015995:Prevalence; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D055815:Young Adult
D005492:Folic Acid; D014805:Vitamin B 12