Table 1. Vitamin D intake, and serum concentrations of 25-OHD3 and VDBP for the study participants by demographic group and season (mean ± standard deviation).
| Vitamin D Intake (IU/day) | 25-OHD3 concentration (nmol/L) | VDBP concentration (ug/ml) | |||||||
| Variable (N = winter, summer) | Winter | Summer | Winter | Summer | Winter | Summer | |||
| Total (N = 45, 46) | 271.4±214.4 | 298.3±226.1 | 66.5±34.5 | 103.3±41.8∧ | 364.3±124.6 | 204.5±78.8∧ | |||
| Males (N = 20, 21) | 285.0±222.3 | 311.3±233.8 | 63.5±26.0 | 100.9±44.5∧ | 375.7±158.1 | 204.2±94.2∧ | |||
| Females (N = 25, 25) | 260.2±211.8 | 287.4±223.7 | 69.9±40.7 | 105.3±40.2∧ | 353.0±94.6 | 208.2±64.9∧ | |||
| <40 years old (N = 19, 20) | 216.9±170.2 | 281.5±228.1 | 46.5±18.4 | 77.7±32.8∧ | 434.8±104.5 | 227.7±82.4∧ | |||
| ≥40 years old (N = 26, 26) | 276.0±236.9 | 320.0±228.3 | 82.1±36.3* | 122.7±37.5*∧ | 310.7±114.9* | 190.2±73.1*∧ | |||
| BMI (Kg/m2) <25 (N = 10, 10) | 314.4±187.7 | 391.7±237.0 | 57.1±30.7 | 102.4±57.2 | 392.3±135.9 | 220.3±59.2∧ | |||
| BMI (Kg/m2) ≥25 (N = 34, 34) | 259.9±223.9 | 277.9±223.7 | 67.0±31.8 | 103.5±37.2∧ | 354.8±123.5 | 202.3±83.8∧ | |||
| No vitamin D supplements (N = 39, 38) | 231.0±198.2 | 257.0±216.1* | 60.8±30.1 | 96.5±42.2∧ | 365.3±129.2 | 209.3±82.6 | |||
| Vitamin D supplements (<400 IU/day) (N = 6, 8) | 534.1±135.3* | 494.3±188.1 | 104.9±40.0* | 133.9±25.1*∧ | 368.7±109.7 | 191.0±54.8 | |||
∧difference between seasons p<0.005 (ANOVA).
*
difference within sub-groups p<0.005 (ANOVA ).