Table 1.

Comparison between the different studied groups according to serum vitamin D concentration

Vitamin D (ng/ml)	Negative control	UVB exposed	Vitamin D supplemented	P
Week 0	13.48 ± 1.01	29.69 ± 0.99	12.78 ± 0.92	< 0.001*
	p1 < 0.001*, p2 = 0.262, p3 < 0.001*
Week 1	15.72 ± 0.79	35.11 ± 1.9	15.12 ± 0.85	< 0.001*
	p1 < 0.001*, p2 = 0.555, p3 < 0.001*
Week 2	15.64 ± 1.37	29.64 ± 2.18	17.29 ± 0.73	< 0.001*
	p1 < 0.001*, p2 = 0.06, p3 < 0.001*
Week 3	17.51 ± 0.64	29.25 ± 1.83	18.34 ± 0.65	< 0.001*
	p1 < 0.001*, p2 = 0.278, p3 < 0.001*
Week 4	18.5 ± 0.67	25.08 ± 1.26	19.14 ± 0.79	< 0.001*
	p1 < 0.001*, p2 = 0.298, p3 < 0.001*
Week 5	18.28 ± 0.56	28.42 ± 1.15	20.1 ± 1.07	< 0.001*
	p1 < 0.001*, p2 < 0.001*, p3 < 0.001*
Week 6	21.07 ± 1.11	33.72 ± 1.98	21.75 ± 1.75	< 0.001*
	p1 < 0.001*, p2 = 0.634, p3 < 0.001*
Week 7	20.7 ± 0.79	32.97 ± 1.61	19.91 ± 0.84	< 0.001*
	p1 < 0.001*, p2 = 0.287, p3 < 0.001*
p0	< 0.001*	< 0.001*	< 0.001*

p: p value for comparing between the different studied groups

p0: p value for comparing between different weeks in each group

p1: p value for comparing between Negative cont. and UV exposed

p2: p value for comparing between Negative cont. and vitamin D-supplemented group

p3: p value for comparing between UV exposed and vitamin D-supplemented group

^*Statistically significant at p ≤ 0.05