Exploring vitamin D metabolism and function in cancer
Vitamin D is a fat-soluble vitamin obtainable from the diet, as well as a seco-steroidal prohormone produced in the skin by ultraviolet B (UVB, 290–320 nm) from sunlight. Vitamin D, as a precursor of a potent steroid hormone, undergoes two-step metabolism in the liver and kidney to synthesize a biologically active form, calcitriol, which binds to the vitamin D receptor (VDR) to enable its diverse physiological functions1,2. The classical role of vitamin D is to regulate metabolism of calcium and phosphate, which is essential for bone remodeling. However, extensive research over the past decades has suggested that low sunlight exposure and vitamin D deficiency are also associated with the increased risk of many other extra-skeletal diseases such as cancer3–6.