The Relationship between Vitamin D Status, Intake and Exercise Performance in UK University-level Athletes and Healthy Inactive Controls

The potential ergogenic effects of vitamin D (vitD) in high performing athletes has received considerable attention in the literature and media. However, little is known about non-supplemented university athletes and students residing at a higher latitude. This study aimed to investigate the effects of vitD (biochemical status and dietary intake) on exercise performance in UK university athletes and sedentary students. Physically healthy male and female university students and athletes from the University of Surrey (51.2ºN) were recruited between January and March (2018) to take part in this study. A total of 50 participants (n= 24 males, n= 26 females) were included, 34 (n=18 male, n=16 female) were university athletes competing in a variety of sports. 

Fasted serum vitD status and sunlight exposure were assessed using LC-MS/MS and dosimetry, respectively. Body composition was measured through the use of a dual-energy x-ray absorptiometry (DEXA) whole body scan (Hologic QDR, Hologic inc. USA). Muscular strength of the upper and lower body was assessed using dominant arm handgrip and knee extensor dynamometry (KE) of the non-dominant leg.  Countermovement jump (CMJ) and aerobic fitness were measured using an Optojump and VO2max test using a stationery cycle ergometer, respectively.