Background: Vitamin D and vitamin B deficiency are common in elderly subjects and are important risk factors for osteoporosis and age-related diseases. Supplementation with these vitamins is a promising preventative strategy. The objective of this study was to evaluate the effects of vitamins D3 and B supplementation on bone turnover and metabolism in elderly people.
Methods: Healthy subjects (n=93; >54 years) were randomly assigned to receive either daily vitamin D3 (1200 IU), folic acid (0.5 mg), vitamin B12 (0.5 mg), vitamin B6 (50 mg), and calcium carbonate (456 mg) (group A) or only vitamin D3 plus calcium carbonate (group B) in a double blind trial. We measured at baseline and after 6 and 12 months of supplementation vitamins, metabolites, and bone turnover markers.
Results: At baseline mean plasma 25-hydroxy vitamin D [25(OH)D] was low (40 or 30 nmol/L) and parathormone was high (63.7 or 77.9 pg/mL). 25(OH)D and parathormone correlated inversely. S-Adenosyl homocysteine and S-adenosyl methionine correlated with bone alkaline phosphatase, sclerostin, and parathormone. One year vitamin D3 or D3 and B supplementation increased plasma 25(OH)D by median 87.6% (group A) and 133.3% (group B). Parathormone was lowered by median 28.3% (A) and 41.2% (B), bone alkaline phosphatase decreased by 2.8% (A) and 16.2% (B), osteocalin by 37.5% (A) and 49.4% (B), and tartrate-resistant-acid-phosphatase 5b by 6.1% (A) and 36.0% (B). Median total homocysteine (tHcy) was high at baseline (group A: 12.6, group B: 12.3 µmol/L) and decreased by B vitamins (group A) to 8.9 µmol/L (29.4%). tHcy lowering had no additional effect on bone turnover.
Conclusions: One year vitamin D3 supplementation with or without B vitamins decreased the bone turnover significantly. Vitamin D3 lowered parathormone. The additional application of B vitamins did not further improve bone turnover. The marked tHcy lowering by B vitamins may modulate the osteoporotic risk.