title: Vitamin B₁₂ and vegetarian diets.
abstract: Vitamin B₁₂ is found almost exclusively in animal-based foods and is therefore a nutrient of potential concern for those following a vegetarian or vegan diet. Vegans, and anyone who significantly limits intake of animal-based foods, require vitamin B₁₂-fortified foods or supplements. Vitamin B₁₂ deficiency has several stages and may be present even if a person does not have anaemia. Anyone following a vegan or vegetarian diet should have their vitamin B₁₂ status regularly assessed to identify a potential problem. A useful process for assessing vitamin B₁₂ status in clinical practice is the combination of taking a diet history, testing serum vitamin B₁₂ level and testing homocysteine, holotranscobalamin II or methylmalonic acid serum levels. Pregnant and lactating vegan or vegetarian women should ensure an adequate intake of vitamin B₁₂ to provide for their developing baby. In people who can absorb vitamin B₁₂, small amounts (in line with the recommended dietary intake) and frequent (daily) doses appear to be more effective than infrequent large doses, including intramuscular injections. Fortification of a wider range of foods products with vitamin B₁₂, particularly foods commonly consumed by vegetarians, is likely to be beneficial, and the feasibility of this should be explored by relevant food authorities.
authors.affiliation: Sydney Adventist Hospital, Sydney, NSW, Australia. carol.zeuschner@sah.org.au.
authors.forename: Carol L
authors.initials: CL
authors.lastname: Zeuschner
authors.affiliation: Sydney Adventist Hospital, Sydney, NSW, Australia.
authors.forename: Bevan D
authors.initials: BD
authors.lastname: Hokin
authors.affiliation: Northside Nutrition and Dietetics, Sydney, NSW, Australia.
authors.forename: Kate A
authors.initials: KA
authors.lastname: Marsh
authors.affiliation: Corporate Nutrition, Sanitarium Health and Wellbeing, Berkeley Vale, NSW, Australia.
authors.forename: Angela V
authors.initials: AV
authors.lastname: Saunders
authors.affiliation: Corporate Nutrition, Sanitarium Health and Wellbeing, Berkeley Vale, NSW, Australia.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Reid
authors.affiliation: Sanitarium Health and Wellbeing Services, Sanitarium Health and Wellbeing, Sydney, NSW, Australia.
authors.forename: Melinda R
authors.initials: MR
authors.lastname: Ramsay
mesh_terms: D014676:Diet, Vegetarian; D006801:Humans; D009751:Nutritional Requirements; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D014805:Vitamin B 12