Vitamin D3 Reduced Risk of Advanced Cancer

The secondary analysis of a US randomized, double-blind, placebo-controlled clinical trial suggested that vitamin D₃ apparently reduced the risk of developing advanced cancer among adults who have normal but not elevated body mass index (BMI). The trial included 25 871 randomized participants (51% female; mean age, 67.1 years), 1617 were diagnosed with invasive cancer over a median intervention period of 5.3 years. No significant differences for cancer incidence by treatment arm were observed. However, a significant reduction in advanced cancers (metastatic or fatal) was found for those randomized to vitamin D₃ compared with placebo (226 of 12 927 assigned to vitamin D₃ [1.7%, 2000 IU/d] and 274 of 12 944 assigned to placebo [2.1%]; HR, 0.83). When stratified by BMI, there was a significant reduction for the vitamin D₃ arm in incident metastatic or fatal cancer among those with normal BMI (BMI<25: HR, 0.62) but not among those with overweight or obesity (BMI 25-<30: HR, 0.89; BMI≥30: HR, 1.05). The results are in line with previous studies and suggest a stronger benefit of vitamin D on cancer mortality and survival than cancer incidence, especially in individuals with normal weight. Source: https://jamanetwork.com/; https://www.nejm.org/