Chatterjee R, Fuss P, Vickery EM, et al. - Experts aspired to explore whether vitamin D supplementation reduces the risk of cancer and precancers in a population with prediabetes and overweight/obesity who are at higher risk of cancer than the general population. Participants had prediabetes, were overweight or obese, and had not had cancer in the past five years. There were 89 cancer cases among 2385 participants (mean age 60 years, 25-hydroxyvitamin D 28 ng/mL) over a median follow-up of 2.9 years. Vitamin D supplementation had no effect on the risk of incident cancer or colon polyps in the D2d population of participants with prediabetes and overweight/obesity who were not chosen for vitamin D insufficiency.