Status of Vitamin B12 among healthy adult and elderly population in India: A review

Abstract

Vitamin B12 is a water soluble micronutrient found in animal foods. Its deficiency is not uncommon in India owing to vegetarianism but often unrecognized due to diverse clinical manifestations. This review aims to collate the current data on vitamin B12 status in healthy Indian adult and elderly population. Online database Pubmed was searched for articles published in English between 2000 and 2019. Inclusion criteria con-sisted of original studies conducted on apparently healthy adult and elderly Indian population reporting serum/plasma vitamin B12 levels. Comprehensive literature search identified 14 studies eligible for inclusion. The deficiency prevalence reached 78.5% and 61.7% among adults and elderly, respectively, based on varying cut offs. Higher vitamin B12 levels were reported in women than men. Hyperhomocysteinemia (Hcy >15 mmol/L) was lower in females as compared to males (60% vs 90%, 14.9% vs 57.4% and 3.6% vs 20.9% respectively in three studies). Vitamin B12 deficiency was higher in vegetarians. The results indicate that inadequate vitamin B12 status is a wide spread problem in the Indian population. However, variety of laboratory methods and cut-offs of vitamin B12 deficiency and the het-erogeneity in results pose challenges to draw clear conclusions on the extent of vitamin B12 deficiency in India. This review, therefore, highlights the need for more evidence based research to define age and sex specific cut offs for defining vitamin B12 deficiency.