Table 2.

Summary of the effect of prenatal vitamin D supplementation on respiratory health parameters (pooled RR)

	Outcome	Meta-analysis			Heterogeneity
		RR	(95% CI)	P-value	I2	P-value
1	Asthma	0.89	(0.69–1.15)	0.37	46%	0.10
2	Eczema	0.95	(0.82–1.10)	0.51	0%	0.95
3	LRTIs	0.95	(0.85–1.06)	0.37	0%	0.95
4	IgEa	0.34	(0.12–1.00)	0.05	–
	IgEb	1.03	(0.79–1.33)	0.85	60%	0.06
	IgE total	0.97	(0.73–1.29)	0.82	63%	0.03
5	URTIs	0.89	(0.73–1.07)	0.22	0%	0.58
6	Allergic rhinitis	1.03	(0.69–1,54)	0.87	43%	0.17

IgE; Immunoglobulin E, LRTI; Lower respiratory tract infection, URTI; Upper respiratory tract infection, RR; relative risk.

^aSubgroup analysis of children who received vitamin D in the first 6 months.

^bchildren who didn't receive vitamin D supplementation.