title: Dietary intake of cobalamin in elderly people who have abnormal serum cobalamin, methylmalonic acid and homocysteine levels.
abstract: OBJECTIVE
  To determine if poor dietary intake can explain the cobalamin-related abnormalities often seen in the elderly.
  
  
  METHODS
  Prospective laboratory survey with a follow-up dietary assessment.
  
  
  METHODS
  Social centers for the elderly and an outpatient clinic.
  
  
  METHODS
  Ninety-five free-living subjects >60y old with abnormal or suspicious findings in cobalamin-related tests and 78 subjects >60y old with normal results.
  
  
  METHODS
  Serum cobalamin, methylmalonic acid and homocysteine determinations to assess cobalamin status and a one year food-frequency questionnaire to assess cobalamin intake.
  
  
  RESULTS
  Only three of the 173 subjects (1.7%), one of whom had normal cobalamin status, ingested <2 microg cobalamin/d, the Recommended Daily Allowance. Sixty-nine subjects (39.9%) ingested <6 microg/d, but they did not have more abnormal serum cobalamin or metabolite values than those ingesting >6 microg. Ordering all subjects by quintiles according to cobalamin intake revealed no significant trends or differences in any of the serum values either. Moreover, arranging subjects by results of tests of cobalamin status showed that the subjects with abnormal cobalamin status did not differ in cobalamin intake from those with normal cobalamin status, although they did differ in use of supplements. Finally, cobalamin intake, with or without supplements, did not correlate with serum cobalamin or metabolite levels. The absence of any association between cobalamin status and intake contrasts sharply with the significant correlation between folate intake and folate status (P = 0.0001).
  
  
  CONCLUSIONS
  The high frequency of mildly abnormal cobalamin status in the elderly cannot be attributed to poor intake of cobalamin. Nondietary explanations, such as malabsorption and other phenomena, must always be sought to explain mild cobalamin deficiency in the elderly.
authors.affiliation: Department of Medicine, University of Southern California School of Medicine and Los Angeles County-USC Medical Center, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Howard
authors.forename: C
authors.initials: C
authors.lastname: Azen
authors.forename: D W
authors.initials: DW
authors.lastname: Jacobsen
authors.forename: R
authors.initials: R
authors.lastname: Green
authors.forename: R
authors.initials: R
authors.lastname: Carmel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood; D006710:Homocysteine / Q000097:blood; D006801:Humans; D008297:Male; D008764:Methylmalonic Acid / Q000097:blood*; D008875:Middle Aged; D009752:Nutritional Status; D011446:Prospective Studies; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000097:blood*
chemical_list: D006710:Homocysteine; D008764:Methylmalonic Acid; D005492:Folic Acid; D014805:Vitamin B 12