Table 4. Determinants of 25-hydroxyvitamin D concentrations: results from simple linear and multivariate regression analyses.

	Simple linear regression			Multivariate regression†
Variables	β	SE	P	β	SE	P
Sunbed use ‡	18.98	10.04	0.062	21.94	9.18	0.019
Supplement use §	15.73	6.52	0.018	13.33	6.06	0.031
Travel to southern latitude ¶	10.36	4.76	0.033	10.05	4.42	0.026
Season ††	9.21	4.30	0.035	12.04	3.95	0.003
Estrogen contraceptive use ‡‡	10.26	5.59	0.070	11.66	5.06	0.024

^†The multivariate model has a combined coefficient of determination of 0.27. All five variables were included in multivariate analysis.

^‡Within the last 30 days.

^§≥5 µg/day.

^¶Within the last 6 months.

^††Summer (May–October) and winter (November–April).

^‡‡Yes/no.