Folic acid and vitamin B(12) supplementation lowers plasma homocysteine but has no effect on serum bone turnover markers in elderly women: a randomized, double-blind, placebo-controlled trial.

ABSTRACT

An elevated homocysteine level is a newly recognized risk factor for osteoporosis. Older individuals may have elevated homocysteine levels due to inadequate folate intake and/or lower absorption of vitamin B(12). The aim of this study was to determine whether there is an impact of folic acid and vitamin B(12) supplementation on homocysteine levels and, subsequently, on bone turnover markers in older women with mildly to moderately elevated homocysteine levels. It is hypothesized that supplementation with folic acid and vitamin B(12) will improve homocysteine levels and, in turn, positively modify bone turnover markers in this population. This randomized, double-blind, placebo-controlled trial included 31 women (65 to 93 years) with homocysteine levels greater than 10 µmol/L. Participants were randomly assigned to receive either a daily folic acid (800 µg) and vitamin B(12) (1000 µg) (n = 17) or a matching placebo (n = 14) for 4 months. The results showed significantly lower homocysteine concentrations in the vitamin group compared to the placebo group (10.6 vs 18.5 µmol/L, P = .007). No significant difference in serum alkaline phosphatase or C-terminal cross-linking telopeptide of type I collagen was found between the vitamin and placebo groups before or after supplementation. The use of folic acid and vitamin B(12) as a dietary supplement to improve homocysteine levels could be beneficial for older women, but additional research must be conducted in a larger population and for a longer period to determine if there is an impact of supplementation on bone turnover markers or other indicators of bone health.