Takeaway
- The combination of vitamin D and calcium, but not vitamin D alone, is associated with reduced risk for any fracture and hip fracture, according to a meta-analysis of observational studies and randomized controlled trials (RCTs).
Why this matters
- Findings support recommendations favoring vitamin D and calcium supplements to prevent fracture.
Study design
- Meta-analysis of 11 observational studies (n=39,141) and 17 RCTs.
- Observational studies were required to involve at least 200 fracture events, and RCTs must have enrolled ≥500 participants.
- Primary outcomes: any fracture and hip fracture.
- Funding: Sino-British Fellowship Trust.
Key results
- Observational studies:
- Each increase of 10.0 ng/mL vitamin D was associated with reduction in:
- Any fracture: adjusted rate ratio [aRR]: 0.93 (95% CI, 0.89-0.96).
- Hip fracture: aRR, 0.80 (95% CI, 0.75-0.86).
- Each increase of 10.0 ng/mL vitamin D was associated with reduction in:
- 11 RCTs of vitamin D alone (n=34,243):
- No reduced risk for:
- Any fracture: RR, 1.06 (95% CI, 0.98-1.14).
- Hip fracture: RR, 1.14 (95% CI, 0.98-1.32).
- No reduced risk for:
- 6 RCTs of vitamin D plus calcium (n=49,282):
- Reduced risk for:
- Any fracture: RR, 0.94 (95% CI, 0.89-0.99).
- Hip fracture: RR, 0.84 (95% CI, 0.72-0.97).
- Reduced risk for:
Limitations
- Vitamin D-only studies were constrained by small sample size, short treatment duration, and high risk for bias.
References
References