Research
Hormonal
Vitamin D deficiency causes proximal muscle weakness and myopathy, which is reversible with supplementation, independent of bone health status.
If you are experiencing unexplained muscle weakness or frequent injuries, get your Vitamin D levels checked. If you are deficient, supplementation can significantly improve muscle power and function, potentially reducing injury risk. Aim for levels above 30 ng/mL for optimal muscle function.
GoodSupportsHIGH confidence
Myopathy associated with vitamin D deficient osteomalacia has been recognized for many years, presenting predominantly a proximal muscle weakness or difficulty in walking upstairs... Subsequently, numerous reports attest to the reversibility of the myopathy associated with vitamin D deficiency.
Why this rating
Supported by multiple RCTs and mechanistic studies, though some conflicting data exists on strength in non-deficient populations.
Source
Vitamin D and Human Skeletal Muscle
Bruce Hamilton · Scandinavian Journal of Medicine and Science in Sports · 2009
DOI 10.1111/j.1600-0838.2009.01016.x
narrative_reviewCited 273×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Vitamin D status influences muscle function through genomic mechanisms involving the Vitamin D Receptor (VDR) and non-genomic rapid calcium handling.Strong
- Vitamin D supplementation improves muscle morphology (Type II fiber size) and function in deficient individuals, but evidence for performance benefits in healthy, non-deficient young athletes is limited.Moderate
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