. 2022 Jul 8;13:909086. doi: 10.3389/fphys.2022.909086

TABLE 5.

Association of athletic performance with VDBP, free, and bioavailable 25-(OH)D concentration by multiple regression analyses* in outdoor players (n = 24).

Physical fitness test variables	VDBP [µmol/L]		Free 25-(OH)D M1 [pg/mL]		Free 25-(OH)D M2 [pg/mL]		Bioavailable 25-(OH)D [ng/mL]
Physical fitness test variables	ß (95% CI)	p-value	ß (95% CI)	p-value	ß (95% CI)	p-value	ß (95% CI)	p-value
VO_2max (ml/kg/min)	−0.141 (−0.565–−0.282)	0.51	0.073 (−0.353–−0.500)	0.74	0.072 (−0.354–−0.499)	0.74	0.069 (−0.358–−0.496)	0.75
Handgrip strength L (kg)	−0.282 (−0.692–−0.129)	0.18	0.135 (−0.289–−0.559)	0.53	0.131 (−0.293–−0.555)	0.54	0.141 (−0.283–−0.564)	0.51
Handgrip strength R (kg)	0.021 (−0.407–−0.448)	0.92	0.079 (−0.348–−0.505)	0.72	0.079 (−0.348–−0.505)	0.72	0.096 (−0.330–−0.521)	0.66
Jump height (cm)	0.160 (−0.309–−0.629)	0.50	0.201 (−0.265–−0.666)	0.40	0.203 (−0.263–−0.668)	0.39	0.185 (−0.282–−0.652)	0.44
Peak force (N)	−0.133 (−0.604–−0.338)	0.58	0.289 (−0.166–−0.744)	0.21	0.289 (−0.166–−0.744)	0.21	0.246 (−0.214–−0.707)	0.29
Peak velocity (m/s)	0.158 (−0.311–−0.628)	0.51	0.186 (−0.281–−0.653)	0.44	0.187 (−0.280–−0.654)	0.43	0.171 (−0.298–−0.639)	0.48
Peak power (W)	−0.064 (−0.539–−0.410)	0.79	0.356 (−0.089–−0.800)	0.12	0.356 (−0.089–−0.800)	0.12	0.319 (−0.132–−0.769)	0.17
RSImod (m/s)	−0.038 (−0.513–−0.437)	0.88	0.232 (−0.231–−0.694)	0.33	0.233 (−0.229–−0.695)	0.32	0.238 (−0.224–−0.700)	0.31
Peak force (N/kg)	−0.016 (−0.492–−0.459)	0.95	0.089 (−0.385–−0.562)	0.71	0.090 (−0.383–−0.564)	0.71	0.088 (−0.386–−0.561)	0.72
Peak power (W/kg)	0.021 (−0.455–−0.496)	0.93	0.222 (−0.241–−0.686)	0.35	0.223 (−0.240–−0.686)	0.35	0.217 (−0.247–−0.681)	0.36
Peak propulsive force/kg [N/kg]	−0.040 (−0.515–−0.435)	0.87	0.106 (−0.367–−0.578)	0.66	0.107 (−0.365–−0.580)	0.66	0.104 (−0.369–−0.577)	0.67
AVG propulsive force/kg [N/kg]	−0.087 (−0.561–−0.386)	0.72	0.298 (−0.155–−0.752)	0.20	0.299 (−0.154–−0.753)	0.20	0.303 (−0.150–−0.756)	0.19
Peak propulsive power/kg (W/kg)	−0.141 (−0.565–−0.282)	0.96	0.235 (−0.227–−0.697)	0.32	0.236 (−0.226–−0.698)	0.32	0.231 (−0.231–−0.694)	0.33
AVG propulsive power/kg (W/kg)	−0.282 (−0.692–−0.129)	0.82	0.231 (−0.232–−0.693)	0.33	0.233 (−0.230–−0.695)	0.32	0.224 (−0.239–−0.687)	0.34

Statistically significant variables were adjusted for age, body mass, and body fat; ß, unstandardized coefficient; 95% CI, confidence interval; VDBP, vitamin D binding protein; VO₂max, maximal oxygen uptake; L, left; R, right; CMJ, countermovement vertical jump; AVG, average; M1, equations by Bikle et al. (1986); M2, equations by Vermeulen et al. (1999).