Profesyonel Voleybolcularda Serum 25(Oh)D Vitamini Düzeyi İle Beslenme Durumu ve Fiziksel Performans İlişkisi
In this study, we aimed to determine the relationship between serum 25(OH)D levels and dietary factors, body composition, physical performance, and inflammatory/oxidative stress markers in elite volleyball players. Forty-seven healthy elite male volleyball players aged 18-36 who are registered to Turkey Volleyball Federation were enrolled for the baseline measurements (early season), 37 athletes completed the second measurements (end season). Anthropometric/performance/body composition measurements, routine biochemical and urine analyses of the participants were evaluated. Serum 25(OH)D, Parathyroid Hormone (PTH) and calcium levels of the athletes, besides some inflammatory (serum C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6)) and oxidative stress markers’ (malondialdehyde (MDA) and total antioxidant capacity (TAC)) levels were measured. To assess nutritional status of the participants, 3-day food consumption records were collected at the beginning and end of the season. Three-day (1-off/1-single/1-double training) 24-hours physical activity records, SenseWear® Armband records were collected in the baseline and follow-up measurements to assess the physical activity of the individuals. Besides the anthropometric measurements (circumferential and skinfold thickness (SF)) and body composition analysis (BIA); performance variables (handgrip, 0-10/20m sprints, vertical jump, Wingate tests) of the athletes were evaluated. Serum 25(OH)D levels were below the optimal for the majority of the athletes for both periods (beginning/end of season: 22,6±8,4/17,5±4,5 IU/L); vitamin D levels, which was “inadequate” at the early season, decreased significantly towards the end of the season and was “deficient” levels. In the early season, there was a negative correlation between 25(OH)D levels and chest SF (r=-0,427, p=0,003), hip circumference (r=-0,371, p=0,01), MUAC (r=-0,383, p=0,008). In the early season, 25(OH)D levels was positively correlated with waist/hip ratio (r=0,300, p=0,04). At the end of the season, the negative relationship between 25(OH)D levels and MUAC was significant. For the beginning/end season, the relationship between serum 25(OH)D levels and performance variables was not significant (p>0,05). At the end of the season, the average daily energy, macro, and micronutrient intake of the athletes, were not different compared to the beginning (p>0,05). The intake of all nutrients was at least within Dietary Guidelines for Turkey recommendations; whereas the intake of some nutrients (protein, A, E, niacin, B2, B6, B12, phosphorus, iron, zinc) were higher than recommended (>133%). At the early season, serum 25(OH)D levels were negatively associated with dietary total energy (r=-0,309, p=0,035), fat (r=-0,292, p=0,047), MUFA (r=-0,346, p=0,017), PUFA (r=-0,305, p=0,037), n-6 fatty acids (r=-0,306, p=0,036), n-6/n-3 ratio (r=-0,295, p=0,044), vitamin E (r=-0,347, p=0,017), sodium (r=-0,292, p=0,046) intake. At the end of the season, serum 25(OH)D levels were positively correlated with dietary retinol intake (r=0,353, p=0,032), n-6/n-3 ratio (r=0,361, p=0,028). As a result, serum 25(OH)D levels are associated with certain dietary factors, body composition, physical performance, inflammatory/oxidative stress levels. Further research is needed to clarify this multifactorial relationship.