Table 2.

Effect of vitamin D and placebo treatment on vitamin D status at 4 and 12 wk in evaluable subjects categorized by vitamin D status at baseline

Baseline vitamin D serum concentration category	na	Vitamin D serum concentration category at study wk 4					Vitamin D serum concentration category at study wk 12
		Deficient	Insufficient	Sufficient	Excess	Totalb	Deficient	Insufficient	Sufficient	Excess	Totalc
Vitamin D
Deficient (<12 ng/ml)	18 (20%)	2 (11%)c	10 (56%)	6 (33%)	0	18	0	3 (17%)	15 (83%)	0	18
Insufficient (12–<20 ng/ml)	28 (32%)	0	5 (18%)	22 (79%)	1 (4%)	28	0	0	27 (96%)	1 (4%)	28
Sufficient (20–50 ng/ml)	40 (45%)	0	0	36 (90%)	4 (10%)	40	0	1 (3%)	34 (85%)	5 (13%)	40
Excess (>50 ng/ml)	2 (2%)	0	0	0	2 (100%)	2	0	0	0	2 (100%)	2
Total	88	2 (2%)	15 (17%)	64 (73%)	7 (8%)	88	0 (0%)	4 (5%)	76 (86%)	8 (9%)	88
Placebo
Deficient (<12 ng/ml)	14 (17%)	11 (79%)	2 (14%)	0	0	13	7 (50%)	4 (29%)	3 (21%)	0	14
Insufficient (12–<20 ng/ml)	28 (35%)	2 (7%)	20 (71%)	6 (21%)	0	28	3 (11%)	17 (61%)	8 (29%)	0	28
Sufficient (20–50 ng/ml)	36 (44%)	0	1 (3%)	34 (94%)	1 (3%)	36	1 (3%)	9 (25%)	26 (72%)	0	36
Excess (>50 ng/ml)	3 (4%)	0	0	0	3 (100%)	3	0	0	0	3 (100%)	3
Total	81	13 (16%)	23 (29%)	40 (50%)	4 (5%)	80	11 (14%)	30 (37%)	37 (46%)	3 (4%)	81

Vitamin D status was based on classification of 25-OHD serum concentration in accordance with IOM 2010 criteria (20).

^aPercentage within column at baseline.

^bDistribution of participants by vitamin D status category was statistically significantly different between randomized treatment groups at wk 4 and 12 (P ≤ 0.001, Fisher's exact test for treatment group differences) but not at study baseline (P = 0.882.

^cPercentage within row (baseline status category) at each visit.