Table 5.

Associations of vitamin D supplementation and achieved 25(OH)D concentrations (nmol/L) using random-effects meta-regression models.

Variables		NN	Beta (95%CI)	R 2	Achieved 25(OH)D concentration, nmol/L
Daily 1,000 IU	Vitamin D supplementation	19	28 (23,33)	0.88	70
	Baseline 25(OH)D concentration, nmol/L		1 (0.8,1.2)
Daily 2,000 IU	Vitamin D supplementation	33	37 (32,42)	0.85	87
	Baseline 25(OH)D concentration, nmol/L		0.9 (0.7,1.1)
Daily 3,000 IU	Vitamin D supplementation	16	40 (29,51)	0.75	84
	Baseline 25(OH)D concentration, nmol/L		1.2 (0.8,1.7)
Weekly 25,000 IU	Vitamin D supplementation	22	43 (33,53)	0.75	91
	Baseline 25(OH)D concentration, nmol/L		1.3 (0.9,1.7)
Weekly 50,000 IU	Vitamin D supplementation	22	64 (50,77)	0.71	107
	Baseline 25(OH)D concentration, nmol/L		1.1 (0.6,1.7)
Monthly 60,000 IU	Vitamin D supplementation	15	31 (20,42)	0.85	85
	Baseline 25(OH)D concentration, nmol/L		0.9 (0.7,1.0)

N indicates the number of trials. R² indicates the R square of meta-regression models.