Table 2.

Summary table of subgroup analysis.

		Mortality			ICU admission			Length of hospital stay			Endotracheal intubation
Subgroup criteria	Analysis type	RR (95% CI)	I2	p value	RR (95% CI)	I2	p value	MD (95% CI)	I2	p value	RR (95% CI)	I2	p value
	Total analysis	0.72 (0.54–0.94)	54%	0.02	0.58 (0.38–0.88)	74%	0.01	−1.00 (−2.16 to 0.16)	63%	0.13	0.78 (0.56–1.08)	60%	0.13
Subgroup by administration method	Single-dose	0.88 (0.69–1.12)	21%	0.3	0.79 (0.61–1.03)	22%	0.08	−1.11 (−2.35 to 0.13)	53%	0.08	−0.10 (−0.23 to 0.03)	42%	0.13
	Continuous dose	0.53 (0.34–0.83)	55%	0.006	0.44 (0.22–0.90)	74%	0.02	−0.50 (−2.23 to 1.22)	69%	0.57	−0.00 (−0.04 to 0.04)	45%	0.87
Subgroup by dosage	≥100,000 IU	0.85 (0.71–1.02)	1%	0.07	0.86 (0.60–1.24)	54%	0.42	−0.91 (−1.83 to 0.01)	57%	0.05	0.59 (0.32–1.09)	38%	0.09
	<100,000 IU	0.30 (0.21–0.44)	0%	<0.0001	0.31 (0.21–0.47)	0%	0.001	−0.97 (−3.24 to 1.29)	48%	0.4	0.96 (0.39–2.35)	34%	0.93
Subgroup by baseline vitamin D status	Vitamin D deficient (25OHD < 30 ng/mL)	0.73 (0.59–0.89)	0%	0.002	0.63 (0.42–0.93)	0%	0.02	−0.62 (−2.17 to 0.92)	72%	0.43	0.92 (0.61–1.37)	36%	0.67
	No baseline restriction	0.73 (0.46–1.15)	73%	0.18	0.59 (0.32–1.11)	86%	0.1	−0.25 (−1.12 to 0.62)	75%	0.57	0.78 (0.34–1.80)	74%	0.57