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.

Balanced carbohydrate ratios are associated with improved diet quality in Australia: A nationally representative cross-sectional study

“…The lack of improvement for vitamin B12 may be due to a reduction in cereal-based products and dishes containing ingredients derived from animals (e.g. pizza, lasagna, biscuits, cakes) as well as limitations placed on vitamin B12 fortification in Australia [ 67 ]. Therefore, examination of these ratios in other countries is of interest, such as the United States where foods are extensively fortified with vitamin B12 [ 67 ].…”

“…pizza, lasagna, biscuits, cakes) as well as limitations placed on vitamin B12 fortification in Australia [ 67 ]. Therefore, examination of these ratios in other countries is of interest, such as the United States where foods are extensively fortified with vitamin B12 [ 67 ].…”

Vitamin-B12 enrichment in tempeh by co-culture withPropionibacterium freudenreichiiduring fermentation

“…As such, analogous compounds may still be present in these samples. This is significant because analogues may have the potential to inhibit vitamin-B12 absorption, and could therefore have anti-nutritive effects (Zeuschner et al, 2013). This was the case for spirulina, once touted as a high source of plant based vitamin-B12 — it is now known that it is actually high in pseudocobalamin which can inhibit vitamin-B12 absorption (Dagnelie et al, 1991; Herbert & Drivas, 1982).…”

The role and impact of abnormal vitamin levels in autism spectrum disorders

“…10 The lack of vitamin consumption caused by a bad diet has recently received much attention and is a major contributor to many childhood health issues worldwide, including megaloblastic anemia (vitamin B12 deficiency), scurvy (vitamin C deficiency), and rickets (vitamin D deficiency). [11][12][13] Recently, an increasing number of studies have emphasized the role of vitamins in the relationship between developmental deficits and metabolic disorders, such as attention deficit disorders and mental development. 14 Vitamins, such as B and D, promote myelin sheath formation and regulate hormone secretion, which are crucial for early brain formation and neurological development 15,16 and possibly have a significant impact on the onset and development of ASD.…”