Abstract
Background: Observational studies suggest that effects of vitamin D may be stronger for cancer mortality than for incidence. Yet, existing randomised controlled trials (RCTs) of vitamin D supplementation have limited power to examine the relationships as their primary end points are not cancer incidence or mortality. Methods: Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality were conducted. Results: Over 2-7 years of duration, vitamin D supplementations had little effect on total cancer incidence (400-1100 IU per day, summary relative risk (RR)=1.00, 95% confidence interval (CI)=0.94-1.06, I 2 =0%; four RCTs with combined 4333 cases), but significantly reduced total cancer mortality (400-833 IU per day, summary RR=0.88, 95% CI=0.78-0.98, I 2 =0%, three RCTs with combined 1190 deaths). Conclusions: Over 2-7 years of duration, the benefit of vitamin D supplementation may be limited to cancer mortality.
Original language | English |
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Pages (from-to) | 976-980 |
Number of pages | 5 |
Journal | British Journal of Cancer |
Volume | 111 |
Issue number | 5 |
DOIs | |
State | Published - 2014 |
Keywords
- cancer incidence
- cancer mortality
- meta-analysis
- randomised controlled trial
- vitamin D intake
- vitamin D supplements