Vitamin D and Your Muscles

You have heard about the importance of adequate vitamin D intake for healthy bones. But what about your muscles?

Several studies have examined the effect of vitamin D supplementation and its potential benefit for muscle size and strength increase. In general, studies have not found that there is a benefit for vitamin D supplementation, even for those with vitamin D deficiency.

There is research demonstrating that when vitamin D is combined with protein or exercise that improvements in muscle strength and size are measurable. This is important for people with sarcopenia, which is gradual muscle loss as commonly experienced by the elderly.


Muscle and Vitamin D Connection

There are a few mechanisms for how vitamin D influences muscle. First, muscle contains vitamin D receptors (VDR). When vitamin D binds with the VDR in muscle, it inhibits the expression of a protein known as myostatin. Myostatin has the function of inhibiting the growth of muscle. By inhibiting myostatin with vitamin D, it allows for muscle growth. In addition, vitamin D influences calcium and phosphate metabolism. Both of these nutrients affect muscle contraction.


Don’t Forget Magnesium

You should also be aware that magnesium deficiency reduces vitamin D levels. Research has demonstrated that low magnesium levels are common in the general population, especially the elderly. In addition, magnesium is a critical mineral involved in muscle contraction.


Stop Sarcopenia

Vitamin D supplementation, along with protein supplementation (such as a quality protein shake) and exercise, as well as magnesium-rich foods and supplementation, should be considered for seniors and the elderly to prevent and treat muscle loss.



Dr. Mark Stengler NMD, MS, is a bestselling author in private practice in Encinitas, California, at the Stengler Center for Integrative Medicine. His newsletter, Dr. Stengler’s Health Breakthroughs, is available at His clinic website is



Bislev, L. S., Grove-Laugesen, D., & Rejnmark, L. (2021). Vitamin D and Muscle Health: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials. Journal of Bone and Mineral Research36(9), 1651. Retrieved from

Cheng, S.-H., Chen, K.-H., Chen, C., Chu, W.-C., & Kang, Y.-N. (2021). The Optimal Strategy of Vitamin D for Sarcopenia: A Network Meta-Analysis of Randomized Controlled Trials. Nutrients13(10). Retrieved from: