The Claim
Vitamin D₃ supplementation at a dosage of 4000 IU per day for a duration of 4 months increases the concentration of vitamin D receptors within muscle cell nuclei and increases the cross-sectional area of muscle fibers in older adults with vitamin D insufficiency.
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.
Taking a daily vitamin D3 pill (4000 IU) for four months can help older adults with low vitamin D levels build stronger muscle fibers by increasing the number of vitamin D receptors inside their muscle cells.
See the scientific wording
Vitamin D₃ supplementation (4000 IU/day) for 4 months increases intramyonuclear vitamin D receptor concentration and muscle fiber cross-sectional area in older adults with vitamin D insufficiency.
What the research says
2 studiesThe study gave older adults with low vitamin D 4000 IU of vitamin D3 daily for 4 months and found their muscle cells grew bigger and had more vitamin D receptors, just like the claim said.
This study gave older adults 4000 IU of vitamin D3 daily for about 4 months and found that their muscle cells made more of the vitamin D receptor, which is exactly what the claim says — but it didn’t measure if their muscle fibers got bigger.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 2 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.