BALTIMORE — Vitamin D may improve neural health and muscle performance, according to data presented at ASBMR 2013.
“We know that treatment with vitamin D has been associated with improved muscle function and performance and a reduced risk for falls,” Robin M. Daly, PhD, FASMF, professor and chair of exercise and aging at the Center for Physical Activity and Nutrition Research at Deakin University in Melbourne, Australia, said during a presentation. “Given that the nervous system sends signals to muscles to produce coordinated muscle contractions, we hypothesized that vitamin D perhaps has a vital role in enhancing muscle responses.”
Daly and colleagues studied the corticomotor excitability and plasticity, serum brain-derived neurotrophic factor, and muscle strength, power and function of healthy adults aged at least 60 years with 25-hydroxyvitamin D <60 nmol/L. The patients were randomly assigned to vitamin D3 2,000 IU daily (n=13) or placebo (n=13) for 10 weeks.
Robin M. Daly
Transcranial magnetic stimulation was conducted to determine the corticospinal adaptations within the nervous system to vitamin D treatment. Researchers also measured changes in muscle strength (via leg extension), power (stair climb), function (timed up and go, four square step test), serum 25-(OH)D and brain-derived neurotrophic factor levels.
Serum 25-(OH)D increased by 34 nmol/L in the vitamin D group compared with no change observed in the control group (–1.2 nmol/L), according to data.
“What we saw is that vitamin D may improve muscle strength and resulted in reduction of cortical excitability and inhibition. This suggests that vitamin D may alter these inhibitory interneurons within the motor cortex and downregulate them so they don’t have such an inhibitory effect on the corticospinal neurons, and thereby enhance muscle responses,” Daly said.
At the conclusion of the study, Daly and colleagues found that those assigned to vitamin D demonstrated an 8% to 11% increase in muscle strength, in addition to a reduction in cortical excitability and intracortical inhibition (P<.05 for all).
These data suggest that vitamin D may have beneficial effects on neural plasticity and functional performance, Daly said. – by Samantha Costa
For more information:
Daly R. Oral Poster Presentations: Clinical #FR0195. Presented at: the American Society for Bone and Mineral Research 2013 Annual Meeting; Oct. 4-7, 2013; Baltimore.
Disclosure: Daly reports no relevant financial disclosures.