Vitamin B(12) deficiency & levels of metabolites in an apparently normal urban south Indian elderly population

BACKGROUND & OBJECTIVES: There is no published literature on the extent of vitamin B(12) deficiency in elderly Indians as determined by plasma vitamin B(12) levels and methylmalonic acid (MMA) levels. Vitamin B(12) deficiency is expected to be higher in elderly Indians due to vegetarianism, varied socio-economic strata and high prevalence of Helicobacter pylori infection. We therefore, studied the dietary habits of south Indian urban elderly population and measured vitamin B(12), MMA red cell folate and homocysteine (Hcy) levels. METHODS: Healthy elderly urban subjects (175, >60 yr) were recruited. Detailed history, physical examination and neurological assessment were carried out. Food Frequency Questionnaire (FFQ) for dietary analysis for daily intake of calories, vitamin B(12), folate and detailed psychological assessment for cognitive functions was carried out. Blood samples were analyzed for routine haematology and biochemistry, vitamin B(12), red cell folate, MMA and Hcy. RESULTS: The mean age of the study population was 66.3 yr. Median values for daily dietary intake of vitamin B(12) and folate were 2.4 and 349.2 μg/day respectively. Sixty two (35%) participants consumed multivitamin supplements. Plasma vitamin B(12) level and the dietary intake of vitamin B(12) was significantly correlated (P=0.157). Plasma vitamin B(12) and Hcy were inversely correlated (P= -0.509). Red cell folate was inversely correlated with Hcy (P= -0.550). Significant negative correlation was observed between plasma vitamin B(12) and MMA in the entire study population (P= -0.220). Subjects consuming vitamin supplements (n=62) had significantly higher plasma vitamin B(12) levels, lower MMA levels and lower Hcy levels. There was no significant correlation between plasma vitamin B(12), MMA, Hcy and red cell folate and any of the 10 cognitive tests including Hindi Mental Status Examination (HMSE). INTERPRETATION & CONCLUSIONS: Our study is indicative of higher vitamin B(12) (2.4 μg/day) intakes in urban south Indian population. Thirty five per cent of the study population consumed multivitamin supplements and therefore, low plasma vitamin B(12) levels were seen only in 16 per cent of the study subjects. However, MMA was elevated in 55 per cent and Hcy in 13 per cent of the subjects.