Vitamin D Deficiency and Muscle Function

Introduction to Vitamin D and Muscle Function

• Vitamin D receptors and the enzyme 1-alpha hydroxylase are present in various tissues including muscles, suggesting direct effects on muscle function 1

Prevalence and Risk Factors

• Approximately 77% of the US population has vitamin D levels less than 30 ng/mL, which is considered insufficient 4
• Risk factors for vitamin D deficiency include decreased dietary intake, decreased sun exposure, darker skin pigmentation, older age, inflammatory bowel disease, malabsorptive conditions, being homebound or institutionalized, and living at high latitudes 1

Clinical Evidence

• Higher dose supplemental vitamin D (700-1000 IU/day) has been shown to reduce the risk of falls by 19% in elderly individuals 2, 5
• Adequate vitamin D status improves muscle performance and reduces the risk of falling, particularly in elderly individuals 2, 3

Recommended Vitamin D Levels and Supplementation

• The goal of treatment is to achieve and maintain 25(OH)D levels of at least 30 ng/mL 4
• Some experts recommend optimal vitamin D levels of 30-40 ng/mL for musculoskeletal health 2, 4