Folic acid and vitamin B₁₂ supplementation lowers plasma homocysteine but has no effect on serum bone turnover markers in elderly women: a randomized, double-blind, placebo-controlled trial.

摘要

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 B₁₂. The aim of this study was to determine whether there is an impact of folic acid and vitamin B₁₂ 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 B₁₂ 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 mumol/L. Participants were randomly assigned to receive either a daily folic acid (800 mug) and vitamin B₁₂ (1000 mug) (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 mumol/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 B₁₂ 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