title: Vitamin B₁₂ deficiency & levels of metabolites in an apparently normal urban south Indian elderly population.
abstract: OBJECTIVE
  There is no published literature on the extent of vitamin B₁₂ deficiency in elderly Indians as determined by plasma vitamin B₁₂ levels and methylmalonic acid (MMA) levels. Vitamin B₁₂ 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 B₁₂, 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 B₁₂, folate and detailed psychological assessment for cognitive functions was carried out. Blood samples were analyzed for routine haematology and biochemistry, vitamin B₁₂, 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 B₁₂ and folate were 2.4 and 349.2 μg/day respectively. Sixty two (35%) participants consumed multivitamin supplements. Plasma vitamin B₁₂ level and the dietary intake of vitamin B₁₂ was significantly correlated (P=0.157). Plasma vitamin B₁₂ 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 B₁₂ and MMA in the entire study population (P= -0.220). Subjects consuming vitamin supplements (n=62) had significantly higher plasma vitamin B₁₂ levels, lower MMA levels and lower Hcy levels. There was no significant correlation between plasma vitamin B₁₂, MMA, Hcy and red cell folate and any of the 10 cognitive tests including Hindi Mental Status Examination (HMSE).
  
  
  CONCLUSIONS
  Our study is indicative of higher vitamin B₁₂ (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 B₁₂ 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.
authors.affiliation: Department of Medicine, St. John's Medical College Hospital, Bangalore, India. vineeta_shobha@yahoo.co.in
authors.forename: Vineeta
authors.initials: V
authors.lastname: Shobha
authors.forename: Subhash D
authors.initials: SD
authors.lastname: Tarey
authors.forename: Ramya G
authors.initials: RG
authors.lastname: Singh
authors.forename: Priya
authors.initials: P
authors.lastname: Shetty
authors.forename: Uma S
authors.initials: US
authors.lastname: Unni
authors.forename: Krishnamachari
authors.initials: K
authors.lastname: Srinivasan
authors.forename: Anura V
authors.initials: AV
authors.lastname: Kurpad
mesh_terms: D000368:Aged; D014676:Diet, Vegetarian; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005492:Folic Acid / Q000097:blood; D016481:Helicobacter Infections / Q000378:metabolism; D016480:Helicobacter pylori / Q000302:isolation & purification; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008764:Methylmalonic Acid / Q000097:blood*; D008875:Middle Aged; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000453:epidemiology* / Q000378:metabolism*
chemical_list: D006710:Homocysteine; D008764:Methylmalonic Acid; D005492:Folic Acid; D014805:Vitamin B 12
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