Atopic dermatitis and inflammatory skin disease
Direct infant UV light exposure is associated with eczema and immune development

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Background

Suboptimal vitamin D levels during critical periods of immune development have emerged as an explanation for higher rates of allergic diseases associated with industrialization and residing at higher latitudes.

Objective

We sought to determine the effects of early postnatal vitamin D supplementation on infant eczema and immune development.

Methods

By using a double-blind randomized controlled trial, newborn infants were randomized to receive vitamin D supplementation (400 IU/d) or a placebo until 6 months of age. Some infants also wore personal UV dosimeters to measure direct UV light (290-380 nm) exposure. Infant vitamin D levels were measured at 3 and 6 months of age. Eczema, wheeze, and immune function outcomes were assessed at 6 months of age.

Results

At 3 (P < .01) and 6 (P = .02) months of age, vitamin D levels were greater for the vitamin D–supplemented group than the placebo group, but there was no difference in eczema incidence between groups. Infants with eczema were found to have had less UV light exposure (median, 555 Joules per square meter [J/m2; interquartile range, 322-1210 J/m2]) compared with those without eczema (median, 998 J/m2 [interquartile range, 676-1577 J/m2]; P = .02). UV light exposure was also inversely correlated with IL-2, GM-CSF, and eotaxin production to Toll-like receptor ligands.

Conclusion

This study is the first to demonstrate an association between greater direct UV light exposures in early infancy with lower incidence of eczema and proinflammatory immune markers by 6 months of age. Our findings indicate that UV light exposure appears more beneficial than vitamin D supplementation as an allergy prevention strategy in early life.

Section snippets

Study design

This study was a double-blind, placebo-controlled RCT. Healthy term (delivered >37 weeks' gestation) singleton infants were recruited before 28 days of age. All the infants had a first-degree relative (mother, father, or sibling) with a history of allergic disease (asthma, eczema, and allergic rhinitis) to reduce heterogeneity in immune function outcomes. This study excluded infants whose mothers had smoked during pregnancy or had an underlying immunodeficiency/autoimmune disease or those with

Infant characteristics

Enrollment began on October 9, 2012, and ended on January 23, 2017. A total of 195 infants were randomized into the trial, 97 to the intervention vitamin D group and 98 to the placebo group. Fig 1 shows the participant flow diagram. Baseline characteristics of the 2 groups are described in Table I. Allocations in the vitamin D group compared with those in the placebo group were not different across seasons (P = .24). Data collection was completed on July 4, 2017. Ninety-two percent (180/195) of

Discussion

This study is the first to demonstrate an association between greater direct infant UV light exposure in the first 3 months of life and both lower incidence of medically diagnosed infant eczema and lower levels of immune factors associated with allergic inflammation at 6 months of age. Greater UV light exposure was associated with lower production of IL-2, which plays a central role in differentiation of naive CD4 T cells into TH2 cells, with potential implications for allergic disease

References (32)

  • R.J. Mullins et al.

    Latitude, sunlight, vitamin D, and childhood food allergy/anaphylaxis

    Curr Allergy Asthma Rep

    (2012)
  • K.J. Allen et al.

    Vitamin D insufficiency is associated with challenge-proven food allergy in infants

    J Allergy Clin Immunol

    (2013)
  • M. Hewison et al.

    Differential regulation of vitamin D receptor and its ligand in human monocyte-derived dendritic cells

    J Immunol

    (2003)
  • L.E. Jeffery et al.

    Availability of 25-hydroxyvitamin D(3) to APCs controls the balance between regulatory and inflammatory T cell responses

    J Immunol

    (2012)
  • P.H. Hart et al.

    Modulation of the immune system by UV radiation: more than just the effects of vitamin D?

    Nat Rev Immunol

    (2011)
  • C.L. Wagner et al.

    American Academy of Pediatrics Section on Breastfeeding, American Academy of Pediatrics Committee on Nutrition. Prevention of rickets and vitamin D deficiency in infants, children, and adolescents

    Pediatrics

    (2008)

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    D.J.P. is supported by a Career Development Fellowship funded from the Medical Research Future Fund Next Generation Clinical Researchers Program. This study was supported by grants from Telethon–New Children's Hospital Research Fund, Australia; Asthma Foundation of Western Australia, Australia; and the Princess Margaret Hospital Foundation, Australia. The trial intervention and placebo control products were donated by Ddrops, Woodbridge, Ontario, Canada.

    Disclosure of potential conflict of interest: S. L. Prescott reports nonfinancial support from Danone and from Bayer and personal fees from Swisse and from Sanofi, all outside the submitted work. The rest of the authors declare that they have no relevant conflicts of interest.

    ∗

    These authors contributed equally to this work.

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