Vitamin D for Muscle Strength
Vitamin D controls phosphorus, calcium, bone metabolism, and neuromuscular function. Vitamin D can be synthesized by the body, or provided through food and supplements. Vitamin D is found in fortified milk, egg yolks, and saltwater fish. Fifteen minutes of sun exposure a few times per week helps the body to produce adequate vitamin D. Vitamin D deficiency precipitates and exacerbates osteoporosis, causes painful softening and bending of the bone (“rickets”), and increases muscle weakness, which worsens the risk of falls and fractures. Studies indicate that men and women who don’t have enough vitamin D have lower scores on physical performance tests, especially in hand-grip strength. Those with the greatest risk of vitamin D deficiency include the homebound elderly, and people with pigmented skin, cultural or social avoidance of the sun, or gastrointestinal malabsorption. Treatment of vitamin D deficiency can produce an increase in muscle strength and a marked decrease in back and lower-limb pain within 6 months. Adults 50 years of age and older need at least 400 to 800 IUs of vitamin D per day, and people with limited sun exposure may need more.