Protocol: Cochrane Collaboration - Vitamin D supplementation for prevention of cancer in adults

Objectives

To assess the beneficial and harmful effects of vitamin D supplementation for prevention of cancer in adults.

Abstract

This is the protocol for a review and there is no abstract. The objectives are as follows:

To assess the beneficial and harmful effects of vitamin D supplementation for prevention of cancer in adults.
Why it is important to do this review

The available evidence on vitamin D and cancer incidence is intriguing but inconclusive. Results of recently completed randomised clinical trials testing the influence of vitamin D supplementation for cancer prevention are inconsistent. Lappe et al found that vitamin D supplementation is associated with significantly decreased cancer incidence (Lappe 2007). On the contrary, another large randomised clinical trial found no effect of vitamin D and calcium supplementation on cancer incidence (Wactawski-Wende 2006). A recent meta-analysis by Autier and Gandini of 18 randomised clinical trials found significantly lower mortality in vitamin D supplemented participants (Autier 2007). We have been unable to identify any systematic reviews of randomised trials on vitamin D supplementation for cancer prevention.