Vitamin D3 Promotes Not Motor Coordination but Motor Skill Learning without Influence on Muscle Function.

Although motor coordination or motor skill learning are improved by taking vitamin D in the animal experiment, muscle function have not been estimated. Here we examined the effect of vitamin D₃ administration on motor coordination and motor skill learning, muscle strength, and muscle volume in mice fed a vitamin D deficient diet. In mice fed a vitamin D deficient diet, serum calcium and 25(OH)D₃ concentrations were measured. We then conducted Rotarod test, beam walking assay, micro-CT analysis, and forelimb grip strength test. Administration of vitamin D₃ elongated the retention time in the Rotarod test in a time dependent manner. In contrast, the time to reach a beam goal box in beam walking assay was not changed in mice administered with vitamin D₃, compared to the control. Oral administration of vitamin D₃ did not affect muscle strength nor muscle volume. Oral administration of vitamin D₃ promotes not motor coordination but motor skill learning and does not affect muscle function.