Long-term effects of vitamin B-12, folate, and vitamin B-6 supplements in elderly people with normal serum vitamin B-12 concentrations

Background: In the elderly, deficiencies of folate, cobalamin (vitamin B-12 ) and pyridoxal phosphate (vitamin Bg) are common. The metabolites homocyst eine, methylmalonic acid, 2-methylcitric acid and cystathionine have been r eported to be sensitive markers of these vitamin deficiencies. Objective: T he long-term (269 days) effect of an intramuscular vitamin supplement conta ining 1 mg vitamin B-12, 1 1 mg folate, and 5 mg vitamin B-6 On serum conce ntrations of homocysteine (tHcy), methylmalonic acid (MMA), 2-methylcitric acid (2-MCA), and cystathionine (Cysta) was studied in 49 elderly subjects with normal levels of vitamin B-12. Methods: Vitamin supplement was adminis tered 8 times over a 21-day period, metabolite concentrations were measured until day 269 (e.g. 248 days after the end of vitamin supplementation). Re sults: From day 0 to 21, the serum levels of the 3 vitamins increased signi ficantly, after cessation of supplementation the levels returned to baselin e within the follow-up period. The MMA, 2-MCA and tHcy levels decreased dur ing the treatment period significantly and did not reach baseline values wi thin the 248-day period. Cysta levels did not differ significantly from bas eline, either during or after treatment. Conclusion: MMA and 2-MCA levels r ather reflect the availability of vitamins, especially cobalamin, than the actual serum levels. Since deficiencies of folate, cobalamin and pyridoxal phosphate in the elderly may cause hyerhomocysteinemia and hence may have u nfavorable effects on mental performance, determination of MMA and 2-MCA le vels in elderly patients with mental disturbances may be a cost-effective m easure to improve or maintain mental performance. Copyright (C) 2001 S. Kar ger AG,Basel.