25(OH)D levels in trained versus sedentary university students at 64° north

Purpose:25-hydroxyvitamin D (25[OH]D) deficiency is associated with compromised bonemineralisation, fatigue, suppressed immune function and unsatisfactory skeletal muscle recovery.We investigated the risk of 25(OH)D insufficiency or deficiency in endurance athletes comparedto sedentary non-athletes living at 64° north. Methods:University student-athletes (TS) and sedentary students (SS) volunteered to participatein this study. TS engaged in regular exercise while SS exercised no more than 20 minutes/week.Metabolic Equivalent of Task (MET) scores for participants were determined. Vitamin D intake wasassessed using the National Cancer Institute’s 24-hour food recall (ASA24). Fasting plasma 25(OH)D levels were quantified via enzyme-linked immunosorbent assay. Results:TS reported higher activity levels than SS as assessed with MET-minutes/week andranking of physical activity levels (p < 0.05). The reported mean daily intake of vitamin D washigher in TS compared to SS (p < 0.05) while 25(OH)D plasma levels were lower in TS than in SS (p< 0.05). In total, 43.8% of the TS were either insufficient (31.3%) or deficient (12.5%) in 25(OH)D,while none of the SS were insufficient and 13.3% were deficient. Conclusion:TS are at increased risk of 25(OH)D insufficiency or deficiency compared to theirsedentary counterparts residing at the same latitude, despite higher vitamin D intake.