Association of Vitamin D Supplementation and Normal Dietary Intake of Vitamin D With Changes in the Gut Microbiome and Markers of Colorectal Cancer Risk

Although dietary vitamin D supplementation has been used in the clinical setting for decades, the effect of supplementary vitamin D consumption on the structure of the microbiome has not been studied in humans in fine scale or with concomitant adjustment for dietary intake. Understanding the interaction of vitamin D with the microbiome in humans could lead to important advancements in the understanding of how vitamin D together with diet impacts the microbiome composition, and ultimately, risk of EOCRC. This study has the potential to lay the ground work for an adjunctive therapy to manipulate the microbiome to reduce risk of EOCRC. This proposed study is designed to evaluate the effect of vitamin D supplementation on the normal structure of the microbiome and data will not be used to diagnose, prevent, cure or treat disease.