Table 2.

Summary of review on the possible role of vitamin D in the development of food allergy.

References	Study	Age, sample	Results	Definition of vitamin D deficiency
De-Regil et al. (53)	Cochrane review	Variable	Vitamin D supplementation, during pregnancy, both single-dose or continued, increased 25(OH)D3 levels at term; however, the clinical implication of improving the vitamin D concentration and the possible use of this intervention strategy as part of the routine antenatal care are yet to be evaluated	Variable
Mirzakhani et al. (54)	Review	Variable	Well-designed and well-powered clinical trials are needed to determine whether supplementation of vitamin D should be recommended in allergic diseases	Variable
Willits et al. (55)	Review	Variable	No association between food allergy and vitamin D level	Variable
Yepes-Nuñez et al. (56)	Systematic review of randomized and non-randomized studies	Variable	Vitamin D supplementation for pregnant women, breastfeeding women, and infants may not decrease the risk of developing allergic diseases, such as atopic dermatitis (in pregnant women), allergic rhinitis (in pregnant women and infants), asthma and/or wheezing (in pregnant women, breastfeeding women, and infants), or food allergies (in pregnant women). However, they conclude that the potential impact of vitamin D on food allergy remains uncertain	Variable
Saggese et al. (57)	Review	Variable	In food allergies, the role of vitamin D remains controversial	Variable
Hawrylowicz et al. (58)	Review	Variable	Longitudinal studies of vitamin D requirements in utero and post-natally, better understanding of factors that influence bioavailability of vitamin D, and mechanistic insights into vitamin D effects on neonatal-specific immune pathways are awaited	Variable
Matsui et al. (59)	Review	Variable	Fall and winter birth could worse food sensitization	Variable