The VDR gene encodes the nuclear transcription-regulating factor that signals the synthesis of proteins involved in bone mineral homeostasis and cell-cycle regulation. Vitamin D binds with its receptor (vitamin D receptor, VDR) and interacts with other cell-signaling pathways to further modulate these biological effects. VDR is involved in inflammation, insulin-like growth factor signaling, and estrogen-related pathways, processes beyond the activation and regulation of vitamin D and calcium.
The regulation of the VDR gene is important in the efficiency of calcium absorption, making VDR a candidate gene for the regulation of bone strength and metabolism. VDR variants have been associated with the development of several bone conditions such as osteoporosis, vitamin D-dependent rickets type II, multiple sclerosis (MS) and cancers (breast; ovarian, skin and colon). These variants have also been associated with type 1 diabetes, components of cardiometabolic syndrome, obesity, and type 2 diabetes.
The A-allele is associated with mood, osteoporosis, certain cancers, and diabetes. If you carry this allele then it is important to note that your risk can be exacerbated by a caffeine intake > 300 mg/d. It is important for you to eat foods rich in vitamin D as well as test your vitamin D levels regularly. In Functional Medicine, the optimal level is considered to be 70.