Vitamin D supplementation and fracture risk: Evidence for a U-shaped effect.
Study Goal
The researchers aimed to evaluate the efficacy and safety of vitamin D and calcium co-supplementation in reducing fracture risk and improving bone health, particularly in elderly populations.
Results Summary
The study found that vitamin D monotherapy does not reduce fracture risk, but co-supplementation with calcium (1000-1200 mg/day) at daily doses of at least 800 IU vitamin D may modestly benefit elderly individuals with severe vitamin D deficiency. High vitamin D doses without calcium appeared harmful for falls and fracture risk.
Population
Elderly populations, especially those with severe vitamin D deficiency [25(OH)D <25-30 nmol/L (<10-12 ng/mL)].
Effective Dosage
1000-1200 mg/day calcium co-supplemented with at least 800 IU/day vitamin D.
Duration
At least 3-5 years of therapy required.
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
vitamin D status | null | fracture risk | null | null | seems to predict | #1 |
vitamin D status | null | bone mineral density (BMD) | null | null | seems to predict | #2 |
vitamin D monotherapy | no change | risk of fractures | null | null | does not seem to reduce | #3 |
high vitamin D doses | increase | falls | people without vitamin D deficiency and at low fracture risk | null | appear to be harmful | #4 |
high vitamin D doses | increase | fracture risk | people without vitamin D deficiency and at low fracture risk | null | appear to be harmful | #5 |
high vitamin D doses | decrease | BMD | people without vitamin D deficiency and at low fracture risk | null | appear to be harmful | #6 |
Vitamin D supplementation | increase | anti-fracture efficacy | elderly populations, especially those with severe vitamin D deficiency | modest | could be of value | #7 |
Vitamin D supplementation | increase | anti-fall efficacy | elderly populations, especially those with severe vitamin D deficiency | modest | could be of value | #8 |
During the last decade, a cascade of evidence has questioned the anti-fracture efficacy of vitamin D supplementation. In general, vitamin D status, reflected by serum 25-hydroxy-vitamin D [25(OH)D] concentrations, seems to predict fracture risk and bone mineral density (BMD). Despite the well-documented detrimental effect of vitamin D deficiency on bones, vitamin D monotherapy does not seem to reduce the risk of fractures. On the other hand, high vitamin D doses, either at monthly (60,000-100,000 IU) or daily intervals (>4000 IU), appear to be harmful with regard to falls, fracture risk and BMD, especially for people without vitamin D deficiency and at low fracture risk. Therefore, a U-shaped effect of vitamin D on the musculoskeletal system may be supported by the current evidence. Vitamin D supplementation could be of value, at daily doses of at least 800 IU, co-supplemented with calcium (1000-1200 mg/day), in elderly populations, especially those with severe vitamin D deficiency [25(OH)D <25-30 nmol/L (<10-12 ng/mL)], although its anti-fracture and anti-fall efficacy is modest. Good compliance and at least 3-5 years of therapy are required.