The Claim
In humans undergoing resistance training, changes in muscle vitamin D receptor (VDR) expression are correlated with changes in CYP27B1 enzyme expression, but not with changes in plasma vitamin D levels, suggesting that local muscle vitamin D metabolism may be more relevant than systemic vitamin D levels.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
When people lift weights, their muscles seem to adjust how they use vitamin D internally, and that change matches up with how much of a certain enzyme they make in the muscle — but it doesn’t match up with how much vitamin D is floating in their blood. So maybe what’s happening inside the muscle matters more than what’s in the bloodstream.
See the scientific wording
In humans, changes in muscle VDR expression during resistance training are correlated with changes in CYP27B1 (the enzyme that activates vitamin D), but not with plasma vitamin D levels, suggesting local muscle vitamin D metabolism may be more relevant than systemic levels.
What the research says
1 studyStudy: Overexpression of the vitamin D receptor (VDR) induces skeletal muscle hypertrophy
The study shows that more VDR in muscles helps them grow bigger during weight training, but it didn’t check if the enzyme that activates vitamin D inside muscles (CYP27B1) or vitamin D levels in the blood changed — so we can’t say if local muscle vitamin D use matters more than blood levels.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.