RT info:eu-repo/semantics/article T1 Effects of vitamin D supplementation on haematological values and muscle recovery in elite male traditional rowers A1 Mielgo Ayuso, Juan Francisco A1 Calleja González, Julio A1 Urdampilleta, Aritz A1 León Guereño, Patxi A1 Córdova Martínez, Alfredo A1 Caballero García, Alberto A1 Fernández Lázaro, Diego K1 Strength-endurance K1 Vitamin D K1 Hemoglobin K1 Hematocrit K1 Testosterone K1 Cortisol K1 32 Ciencias Médicas K1 23 Química AB Introduction: Deficient levels of 25-hydroxyvitamin D (25(OH)D) (<30 ng/mL) may compromise health and athletic performance. Supplementation with oral vitamin D can favor the state of iron metabolism, and testosterone and cortisol as an indicator of muscle recovery of the athlete with a deficiency. The main aim of this study was to evaluate the influence of eight weeks of supplementation with 3000 IU/day of vitamin D on the hematological and iron metabolism profile, as well as on the analytical values of testosterone and cortisol on elite male traditional rowers. The secondary aim was to examine if serum 25(OH)D is a predictor of testosterone and cortisol levels. Material and Methods: Thirty-six elite male rowers (27 ± 6 years) were assigned to one of the two groups randomly: 1) Control group (CG, n = 18, height: 181.05 ± 3.39 cm and body mass: 77.02 ± 7.55 kg), 2) Group treated with 3,000 IU of vitamin D3/day (VD3G, s = 18, height: 179.70 ± 9.07 cm and body mass: 76.19 ± 10.07 kg). The rowers were subjected to blood tests at the beginning of the study (T1) and after eight weeks of treatment (T2), for the analysis of hematological and hormonal values. Repeated-measures ANOVA with group factor (GC and GVD3) were used to examine if the interaction of the different values was the same or different between the groups throughout the study (time × group) after vitamin D3 treatment. To analyze if 25(OH)D was a good predictor of testosterone, cortisol, and testosterone/cortisol ratio a stepwise regression model was performed. Results: Statistically significant and different increases were observed in the group-by-time interaction of 25(OH)D in VD3G in respect to CG during the study (p < 0.001; VD3G (T1: 26.24 ± 8.18 ng/mL vs. T2: 48.12 ± 10.88 ng/mL) vs CG (T1: 30.76 ± 6.95 ng/mL vs. T2: 35.14 ± 7.96 ng/mL). Likewise, significant differences between groups were observed throughout the study in the group-by-time interaction and changes of hemoglobin (GC: −2.89 ± 2.29% vs. VD3G: 0.71 ± 1.91%; p = 0.009), hematocrit (CG: −1.57 ± 2.49% vs. VD3G: 1.16 ± 1.81%; p = 0.019) and transferrin (CG: 0.67 ± 4.88% vs. VD3G: 6.51 ± 4.36%; p = 0.007). However, no differences between groups were observed in the group-by-time interaction of the hormonal parameters (p > 0.05). Regression multivariate analysis showed that cortisol and testosterone levels were associated with 25(OH)D levels (p < 0.05). Conclusion: Oral supplementation with 3000 IU/day of vitamin D3 during eight weeks showed to be sufficient to prevent a decline in hematological levels of hemoglobin and hematocrit, and improve transferrin of 25(OH)D levels. However, although it was not sufficient to enhance muscle recovery observed by testosterone and cortisol responses, it was observed that serum 25(OH)D levels could be a predictor of anabolic and catabolic hormones. PB MDPI SN 2072-6643 YR 2018 FD 2018 LK https://uvadoc.uva.es/handle/10324/52372 UL https://uvadoc.uva.es/handle/10324/52372 LA eng NO Nutrients, 2018, vol. 10, n. 12, p. 1968. NO Producción Científica DS UVaDOC RD 26-abr-2024