Increased blood levels of vitamin D could help diminish muscular weakness after intense exercise, suggests a new US study.
In the study, 14 active adults were measured for muscular strength in the legs and blood vitamin D concen-trations before and after intense exercise (1). One of the participant’s legs was used for the muscle perfor-mance experiment, while the other acted as a control. The study results showed that muscle weakness was observed in the exercise leg compared with the control leg after physical activity. Low serum levels of vitamin D before, immediately after and 2 to 3 days after exercise were linked to increased immediate and persistent muscular weakness.
The researchers commented that future research should investigate the influence of diverse vitamin D interventions that maintain adequate blood levels on the alleviation of muscle weakness after muscle strain. Research has shown that proximal muscle weakness and diffuse muscle pain are prominent features of the clinical syndrome of vitamin D deficiency (2). The vitamin D receptor (VDR) is expressed in human muscle tissue and VDR activation may promote de novo protein synthesis in muscle. Several observational studies have suggested an association between increasing blood 25 hydroxyvitamin D concentrations and improved muscle strength or lower extremity function in the elderly. In addition, vitamin D supplementation has been shown to increase muscle strength and balance, and to reduce the risk of falling in community-dwelling individuals.