Hyperhomocysteinemia and elevated methylmalonic acid indicate a high prevalence of cobalamin deficiency in Asian Indians

Background: In India, most people adhere to a vegetarian diet, which may le ad to cobalamin deficiency. Objective: The objective was to examine indicators of cobalamin status in A sian Indians. Design: The study population included 204 men and women aged 27-55 y from P une, Maharashtra, India, categorized into 4 groups: patients with cardiovas cular disease (CVD) and diabetes, patients with CVD but no diabetes, patien ts with diabetes but no CVD, and healthy subjects. Data on medical history. lifestyle, and diet were obtained by interviews and questionnaires. Blood samples were collected for measurement of serum or plasma total cobalamin, holotranscobalamin (holoTC), methylmalonic acid (MMA), and total homocystei ne (tHcy) and hemetologic indexes. Results: MMA, tHcy, total cobalamin, and holoTC did not differ significantl y among the 4 groups, therefore, the data were pooled, Total cobalamin show ed a strong inverse correlation with tHcy (r = -0.59) and MMA (r = -0.54), Forty-seven percent of the subjects had cobalamin deficiency (total cobalam in < 150 pmol/L), 73% had low holoTC (< 35 pmol/L), 77% had hyperhomocystei nemia (tHcy > 15 mu mol/L), and 73% had elevated serum MMA (>0.26 mu mol/L) . These indicators of impaired cobalamin status were observed in both veget arians and nonvegetarians. Folate deficiency was rare and only 2.5%, of the subjects were homozygous for the MTHFR 677C -->T polymorphism. Conclusions: About 75% of the subjects had metabolic signs of cobalamin def iciency. which was only partly explained by the vegetarian diet. If impaire d cobalamin status is confirmed in other parts of India, it may have import ant health implications.