Vitamin D supplementation for prevention of cancer: The D2d cancer outcomes (D2dCA) study

Evidence on biological plausibility from mechanistic studies and data from observational studies suggest that vitamin D may be linked to risk of several types of cancer. However, evidence from clinical trials evaluating the effect of vitamin D supplementation on cancer risk is limited. The Vitamin D and Type 2 Diabetes (D2d) study is a multi-center, randomized, placebo-controlled clinical trial conducted to examine the causal relationship...