Older Athletes and Vitamin D's Impact on Glycemic Control

Mechanisms of HbA1C may confound predictions of metabolic risk by vitamin D3 levels in athletes, a study found The research was, conducted by Helmuth Haslacher of the Department of Laboratory Medicine at the Medical University of Vienna in Austria, and colleagues, was published in the journal PLOS One on June 15, 2016.

The researchers set out to investigate whether or not vitamin D3 (25(OH)D) levels in a group of elderly endurance athletes could predict a deterioration in glycemic control compared to a group of controls matched for age and sex. They identified 49 athletes who were 60 years or older and who had participated in a half marathon or a marathon in the previous 3 years and who still trained 2 or more hours per week, as well as 49 controls. The study began in 2009 and ran for three years.

The final analyses consisted of 47 participants in each group, owing to missing information. “At baseline, serum 25(OH)D levels did not differ significantly between the athletes and controls,” said the researchers. There were, however, significant differences when the researchers controlled for seasonal variations.

The researchers say that the “predictive capacity of vitamin D levels on changes in the glycemic state” are particularly important because identifying people at risk of diabetes “represents a key strategy to combat the disease.” While they also say “our results indicate that the relationship between vitamin D levels and future hyperglycemia might not be present in endurance athletes,” they go on to add that a combination of vitamin D serum levels, BMI, and adjusting for seasonal vitamin D variations predicted (pre-)diabetes effectively among the control group.

“To the best of our knowledge, this is the first manuscript that shows that the predictive value of lower 25(OH)D concentrations regarding the risk of (pre-)diabetes might be influenced by intense exercise,” say the researchers, adding, “our findings implicate that life style might modify the relevance of low 25(OH)D concentrations as a risk predictor of future morbidity in elderly patients.”