The Claim
In older mobility-limited women with baseline vitamin D insufficiency, 16 weeks of daily 4,000 IU vitamin D3 supplementation is associated with a 20% increase in skeletal muscle VDR mRNA expression, while placebo is associated with a 3.2-fold decrease, suggesting vitamin D3 may sustainably upregulate VDR gene expression in aging muscle.
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.
In older women who have trouble moving and low vitamin D, taking a daily vitamin D supplement for 4 months might help their muscles make more of a key protein that helps vitamin D work, while those who take a fake pill might see that protein drop instead.
See the scientific wording
In older mobility-limited women with baseline vitamin D insufficiency, 16 weeks of daily 4,000 IU vitamin D3 supplementation is associated with a 20% increase in skeletal muscle VDR mRNA expression, while placebo is associated with a 3.2-fold decrease, suggesting vitamin D3 may sustainably upregulate VDR gene expression in aging muscle.
What the research says
1 studyThe study gave older women vitamin D pills for 16 weeks and found their muscle cells made more of the vitamin D receptor, while those who got fake pills made less — exactly what the claim says.
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.