Building on our discussion of metabolic precision, I’ve been thinking a lot about why we see such varied clinical responses to Vitamin D supplementation.
As a biochemist, I find that we often obsess over serum 25(OH)D levels while ignoring the Vitamin D Receptor (VDR) polymorphism. It’s not just about how much you “pour into the tank”; it’s about the sensitivity of the “ignition.”
In the lab, we see that individuals with specific VDR variants (like FokI or BsmI) require significantly higher systemic levels to achieve the same gene transcription as others. This is why a “one-size-fits-all” 60k IU monthly dose often fails in clinical practice here in India, where genetic diversity in VDR expression is vast.
If the receptor isn’t “listening,” the serum level is just a number on a page. We need to move toward a more nuanced, individualized approach to bone and immune health.
In your practice, do you find that some patients remain symptomatic (bone pain, fatigue) even after their serum levels are “normalized”? Could we be looking at receptor resistance rather than just deficiency?
Great point! Sometimes patients still feel symptoms even when Vitamin D levels look normal. Variations in the Vitamin D Receptor (VDR), like FokI polymorphism, may affect how the body responds.
Absolutely!! This is a sharp observation. Clinical outcomes hinge not just on serum 25(OH)D but on VDR responsiveness, and polymorphisms like FokI/BsmI make “standard dosing” unreliable. Personalized supplementation strategies that integrate receptor genetics could transform bone and immune health management.
An insightful reminder that vitamin D’s effects depend not only on the vitamin itself but also on the vitamin D receptor (VDR). Understanding this interaction is crucial for interpreting research on immunity, metabolism, and overall health.
I have seen such patients especially elderly which have normal serum levels but complain of bone pain. But is receptor testing feasible for the masses.
Yes, I have seen many patients having bone pain, general fatigue, depressed mood even after normal serum level. And this article definitely intrigued me to think about the receptor resistance
