TY - JOUR
T1 - Cancer and vitamin D supplementation: A systematic review and meta-analysis
AU - Goulão, Beatriz
AU - Stewart, Fiona
AU - Ford, John A.
AU - Maclennan, Graeme
AU - Avenell, Alison
PY - 2018/4/1
Y1 - 2018/4/1
N2 - Background: Low 25-hydroxyvitamin D status has been associated with a higher risk of cancer in epidemiologic studies. Objective The aim of this study was to undertake a systematic review and meta-analysis of randomized clinical trials (RCTs) investigating the effect of vitamin D supplementation alone on cancer incidence and mortality. Design: A systematic review was undertaken. MEDLINE, Embase, CENTRAL, conference abstracts, and clinical trial registries were searched (last search March 2017) for RCTs investigating vitamin D supplementation alone. RCTs with ≥12 mo of follow-up and in participants with a mean or median age ≥60 y were eligible. During-study events were used as the main analysis, but after-study events were included in a secondary analysis. Subgroup analyses concerning different forms of vitamin D supplementation, 25-hydroxyvitamin D status at baseline, vitamin D dose, and exclusion of open-label trials were undertaken. Results: Thirty studies in 18,808 participants were included in the systematic review, with a median follow-up ranging from 1 to 6.2 y. The results of the meta-analysis for during-study events showed no evidence of an effect of vitamin D supplementation for cancer incidence (RR: 1.03; 95% CI: 0.91, 1.15) and cancer-related deaths (RR: 0.85; 95% CI: 0.70, 1.04). Including after-study events, the RRs were 1.02 (95% CI: 0.92, 1.13) and 0.85 (95% CI: 0.72, 1.00), respectively. These results did not appear to be affected by baseline 25-hydroxyvitamin D status, vitamin D dose, or the exclusion of open-label trials. Conclusion: We did not find evidence to suggest that vitamin D supplementation alone reduces the incidence of cancer or cancer mortality, even after including long-term follow-up results.
AB - Background: Low 25-hydroxyvitamin D status has been associated with a higher risk of cancer in epidemiologic studies. Objective The aim of this study was to undertake a systematic review and meta-analysis of randomized clinical trials (RCTs) investigating the effect of vitamin D supplementation alone on cancer incidence and mortality. Design: A systematic review was undertaken. MEDLINE, Embase, CENTRAL, conference abstracts, and clinical trial registries were searched (last search March 2017) for RCTs investigating vitamin D supplementation alone. RCTs with ≥12 mo of follow-up and in participants with a mean or median age ≥60 y were eligible. During-study events were used as the main analysis, but after-study events were included in a secondary analysis. Subgroup analyses concerning different forms of vitamin D supplementation, 25-hydroxyvitamin D status at baseline, vitamin D dose, and exclusion of open-label trials were undertaken. Results: Thirty studies in 18,808 participants were included in the systematic review, with a median follow-up ranging from 1 to 6.2 y. The results of the meta-analysis for during-study events showed no evidence of an effect of vitamin D supplementation for cancer incidence (RR: 1.03; 95% CI: 0.91, 1.15) and cancer-related deaths (RR: 0.85; 95% CI: 0.70, 1.04). Including after-study events, the RRs were 1.02 (95% CI: 0.92, 1.13) and 0.85 (95% CI: 0.72, 1.00), respectively. These results did not appear to be affected by baseline 25-hydroxyvitamin D status, vitamin D dose, or the exclusion of open-label trials. Conclusion: We did not find evidence to suggest that vitamin D supplementation alone reduces the incidence of cancer or cancer mortality, even after including long-term follow-up results.
KW - cancer
KW - meta-analysis
KW - mortality
KW - systematic review
KW - Vitamin D
UR - http://www.scopus.com/inward/record.url?scp=85045843767&partnerID=8YFLogxK
U2 - 10.1093/ajcn/nqx047
DO - 10.1093/ajcn/nqx047
M3 - Article
AN - SCOPUS:85045843767
VL - 107
SP - 652
EP - 663
JO - American Journal of Clinical Nutrition
JF - American Journal of Clinical Nutrition
SN - 0002-9165
IS - 4
ER -