Table 2.

Characteristics of patients and interventions performed in the included studies.

Study Number	Patients (Cases vs. Controls)	Average Age (Years) (Cases vs. Controls)	Gender (Female) (Cases vs. Controls)	Vitamin D Intake (IU)	Duration of Vitamin D Supplementation
1 [31] Leis et al.	197 (105 vs. 92)	NR	40.8% vs. 42.2%	48/kg/day vs. 60/kg/day	6 months
2 [32] Jensen et al.	22 (11 vs. 11)	2.2 vs. 3.1	65.6% vs. 72.7%	1 oral bolus of 50,000 + 400/day	6 months
3 [33] Aglipay et al.	703 (349 vs. 354)	2.70 vs. 2.76	45.2% vs. 39.4%	2000/day vs. 400/day	10 months
4 [34] Hueniken et al.	703 (349 vs. 354)	2.70 vs. 2.76	45.2% vs. 39.4%	2000/day vs. 400/day	4–8 months
5 [35] Singh et al.	100 (50 vs. 50)	NR	44.0% vs. 40.0%	1 oral bolus of 300,000 + 400/day	12 months
6 [36] Ducharne et al.	47 (23 vs. 24)	2.9 vs. 2.9	30.0% vs. 42.0%	2 oral boluses of 100,000 (3.5 months apart)	7 months
7 [37] Jadhav et al.	298 (155 vs. 143)	3.1 vs. 3.2	36.2%	1 oral bolus of 120,000 + 400/day vs. 400/day	6 months
8 [38] Xiao et al.	119 (60 vs. 59)	4.8 vs. 4.8	28.3% vs. 30.5%	800/day vs. 400/day	3 months

NR—not reported; IU—international units; cases—received vitamin D; controls—did not receive vitamin D supplementation.