Vitamin D and muscle
2 papers in the library, strongest Moderate.
Graded Moderate · Mendelian randomization using pooled genetic data from European-ancestry studies, though results rest on genetic proxies rather than direct trials in people.
Papers 2
- Genetics Hint Vitamin D Helps Muscle Mass, But Not Grip StrengthModerate2026MedicineResearchers used gene variants tied to lifelong vitamin D levels to test cause and effect, which sidesteps the usual confounders. Higher vitamin D was linked to slightly more muscle mass in the arms and legs in people of European ancestry. But there was no sign it affected grip strength or walking speed, the other main markers of sarcopenia. So vitamin D may support muscle size without translating into measurable strength.
- Low Vitamin D Linked to Muscle Loss, Especially in People With DiabetesModeraten = 7,5202026The journal of nutrition, health & agingIn a study of over 7,500 older adults, low vitamin D was tied to higher odds of sarcopenia (age-related muscle loss). The link was stronger in those with diabetes. In aged diabetic rats, vitamin D3 supplements improved muscle strength and reduced fat buildup inside muscle fibers.
How this map is computed
A mark's size is the number of papers we hold on that pairing. It is a count, not a weighting by study design or sample size.
The fill shows the strongest grade in the cell. One Strong paper among four Preliminary ones still fills it dark, so open the cell to see the rest.
Grades and verdicts are assigned by a named person, never by counting.
An empty cell is a finding: nobody in our library has run that trial yet.