Possible associations of 25(OH) vitamin D status with upper respiratory tract infections morbidity and overtraining syndrome among elite wrestlers

Abstract

Purpose:The purpose of the study is to determine possible association of 25 (OH) vitamin D (VD) level with acute upper respiratory tract infections (URTI) as well as with overtraining syndrome (OS) among elite wrestlers. Material: The study was planned as a prospective, non-interventional, observational study. Participants included 40 elite wrestlers and 60 control individuals. Serum levels of 25(OH) VD and TNF-α, IFN-γ and IL-4 were detected by ELISA technique. Parasites were diagnosed by triple coproscopy. OS was diagnosed on the basis of typical symptoms and decreased performance. Morbidity and frequency of acute URTI in participants were determined by self-reported questionnaire and medical cards. Results: Predominance of VD deficiency/insufficiency was found in elite athletes and the control individuals (P>0.05). Prevalence of VD deficiency/insufficiency depends on the season, but in every season the highest values were observed among athletes. The highest level of TNF-α (31±11.9%) and the lowest of IFN-γ (5.9±2.9%) were observed in athletes with VD deficiency. Changes in the level of IL-4 were less expressed. Frequency of episodes of URTI depends on VD level and the most number was detected in wrestlers with VD deficiency in winter-spring. Symptoms of OS were identified in 17 (42.5%) wrestlers, 6 (35.2%) of them reported about disappearance of OS symptoms after elimination of intestinal parasites. Conclusions:VD deficiency/insufficiency is widely spread both in elite wrestlers and the control individuals. Monitoring of VD level in elite athletes with subsequent correction is necessary. VD deficiency/insufficiency in athletes correlates with high morbidity with URTI and could be associated with OS.