VDR Gene (Vitamin D Receptor)
The gene that dictates the sensitivity of your cells to Vitamin D. It determines how much Vitamin D you actually absorb and utilize, regardless of your blood levels.
Deep Dive
You can have 'normal' Vitamin D levels in a blood test but still be functionally deficient at a cellular level if you have a VDR mutation. The VDR gene encodes the receptor protein that Vitamin D must bind to in order to exert its effects inside the cell.
This genetic blind spot is a common root cause of weak immunity, seasonal depression (SAD), poor bone density, and chronic inflammation. Individuals with certain VDR variants may require significantly higher doses of Vitamin D — or specific co-factors like Vitamin K2 and magnesium — to achieve the same cellular effect as someone without the variant.
Testing your VDR status is essential for anyone who supplements with Vitamin D but still experiences symptoms of deficiency. Without this genetic context, you may be dosing based on blood levels that do not reflect what is actually happening inside your cells.