Associations Between Serum Levels of Vitamin D and Neuromuscular Parameters in Schoolchildren

This cross-sectional study investigated the associations between vitamin D levels, handgrip strength, and gross motor coordination in 86 healthy children (51.2% male). Blood samples were analyzed to measure serum vitamin D levels, handgrip strength was measured using handgrip dynamometry, and motor quotient was assessed using the Körper Koordinationstest für Kinder. Sociodemographic data were collected through a questionnaire. The analyses revealed no influence of vitamin D on handgrip strength. In the regression model, vitamin D was a significant predictor of the motor quotient ( B = 1.35, 95% CI [0.12, 2.57]), independent of covariates. The household income variable also stood out as it was significant both as a predictor of the influence of vitamin D on motor quotient ( B = −59.50, 95% CI [−96.80, −22.20]) and as a moderator of this influence (B = 59.46, 95% CI [10.04, 108.87]). Including sociodemographic factors, such as income, was crucial for understanding the relationship between vitamin D and motor quotient in children. Therefore, it is necessary to discuss and evaluate how different socioeconomic statuses, growth phases, access to balanced nutrition, and physical and metabolic health conditions influence physical performance behavior in the pediatric population.