Vitamin D supplementations during pregnancy could lower risk of eczema in babies

UK: Antenatal cholecalciferol supplementation has a protective effect on the risk of infantile atopic eczema, states MAVIDOS trial data published in the British Journal of Dermatology.

Atopic eczema is a chronic inflammatory condition that causes the skin to become itchy, dry and cracked. It affects approximately 15-20% of children worldwide. Atopic eczema can have a large impact on sufferers, their families, and healthcare. Vitamin D is known to have a regulatory influence on both the immune system and skin barrier function, both critical in the pathogenesis of eczema. Evidence linking prenatal maternal vitamin D supplementation with the offspring's risk of atopic eczema is inconsistent, with most data coming from observational studies.

Within the UK Maternal Vitamin D Osteoporosis Study (MAVIDOS) double-blind, randomised, placebo-controlled trial, Sarah El-Heis, University of Southampton, UK and colleagues tried to examine the influence of maternal cholecalciferol supplementation during pregnancy on the risk of atopic eczema in the offspring at ages 12, 24 and 48 months.

Researchers allocated pregnant women to either cholecalciferol 1000 IU/day or matched placebo, taken from around 14 weeks' gestation until delivery, with the primary outcome of neonatal whole-body bone mineral content. The prevalence of atopic eczema in the offspring was ascertained at ages 12 (n=635), 24 (n=610) and 48 (n=449) months. Mothers and offspring characteristics were similar between the intervention and placebo groups, apart from longer breastfeeding duration in the intervention group.

Key findings of the trial data,

• Offspring of mothers who received 1000 IU cholecalciferol daily had a lower odds ratio (OR) of atopic eczema at age 12 months (OR - 0.55 p=0.04); this effect weakened and was not statistically significant at ages 24 and 48 months OR- 0.76 and 0.75, respectively.

• The statistical interaction of intervention and breastfeeding duration with eczema at age 12 months was not significant (p=0.41),.

• Stratification showed a reduced infantile eczema risk in the intervention group of infants breastfed for ≥1 month (OR -0.48,p=0.03) and not in those breastfed for <1 month (OR -0.80 .p=0.66).

The authors conclude that the study data provide evidence of a protective effect of antenatal cholecalciferol supplementation on the risk of infantile atopic eczema, with the effect potentially being via increased breast milk cholecalciferol levels. The present findings support a developmental influence on atopic eczema and point to a potentially modifiable perinatal influence on atopic eczema.

Sarah El-Heis,Stefania D'Angelo,Elizabeth M. Curtis,Eugene Healy,Rebecca J. Moon,Sarah R. Crozier,Hazel Inskip,Cyrus Cooper,Nicholas C. Harvey,Keith M. Godfrey,The MAVIDOS Trial Group   First published: 28 June 2022 https://doi.org/10.1111/bjd.21721