Physical activity, sedentary behavior, and vitamin D metabolites

Area of Science:

• Endocrinology
• Nutritional Science
• Exercise Physiology

Background:

• Physical activity is known to influence circulating 25-hydroxyvitamin D (25(OH)D).
• The impact of physical activity and sedentary behavior on the biologically active 1α,25-dihydroxyvitamin D (1,25(OH)2D) remains largely unexplored.
• Understanding these relationships is crucial for public health and disease prevention strategies.

Purpose of the Study:

• To investigate the associations between physical activity, sedentary behavior, and circulating vitamin D metabolite concentrations (25(OH)D and 1,25(OH)2D).
• To examine potential sex differences in these associations.
• To explore the role of vitamin D metabolites in the context of physical activity and health outcomes.

Main Methods:

• Cross-sectional analysis of 876 participants from a ursodeoxycholic acid (UDCA) randomized trial.
• Evaluation of continuous vitamin D metabolite measurements and clinical thresholds using multiple linear and logistic regression.
• Models were mutually adjusted for 1,25(OH)2D or 25(OH)D and other confounding factors.

Main Results:

• A significant linear association was found between 1,25(OH)2D and moderate-vigorous physical activity, which was stronger in women than men (p-interaction=0.003).
• Moderate-vigorous physical activity was positively associated with higher 25(OH)D levels (1.54 ng/ml per hour increase, p=0.001).
• Physically active participants had higher odds of sufficient 25(OH)D status (p=0.001); sedentary behavior showed no significant association with either vitamin D metabolite.

Conclusions:

• This study reveals novel associations between physical activity and serum 1,25(OH)2D levels, independent of 25(OH)D concentrations.
• The findings suggest that the biologically active form of vitamin D may mediate the health benefits of physical activity, such as improved bone health and reduced chronic disease risk.
• Further longitudinal research is warranted to confirm these findings and elucidate the role of physical activity and vitamin D metabolites in chronic disease prevention.