The effect of B-vitamins on biochemical bone turnover markers and bone mineral density in osteoporotic patients: a 1-year double blind placebo controlled trial

Background: Hyperhomocysteinemia is a new risk factor for osteoporosis. This study analyzed the effect of a homocysteine (HCY)-lowering treatment in osteoporotic individuals. Methods: Osteoporotic subjects (n=47, 55–82 years) were treated with either a combination of 2.5 mg folate, 0.5 mg vitamin B12 and 25 mg vitamin B6 or placebo. Bone mineral density (BMD) at lumbar spine and hip was measured at baseline and after 1 year. Urinary desoxypyridinoline cross-links (DPD) and plasma levels of tartrate resistant acid phosphatase (TRAP), C-terminal cross-links of collagen I (CTx), pro-collagen type I N-terminal peptide (PINP) and osteocalcin (OC) were measured after 0, 4, 8 and 12 months. Results: B-vitamin supplementation significantly reduced HCY (0 vs. 12 months: 13.6±4.8 vs. 8.9±2.4 μmol/L). Placebo treatment had no effect on HCY (0 vs. 12 months: 12.0±3.4 vs. 12.7±3.9μmol/L). BMD, TRAP, CTx, OC and PINP did not change throughout the study in both groups. Vitamin treatment decreased urinary DPD by –13% (p15 μmol/L, n=8), B-vitamin treatment tended to increase BMD at the lumbar spine, with a t-score from –2.7 to –1.7, and to decrease OC and PINP by approximately 50%. Conclusions: B-vitamin supplementation had no consistent effects on bone turnover or BMD. However, the situation may be different in patients with hyperhomocysteinemia. Clin Chem Lab Med 2007;45:1785–92.