Does Vitamin D Supplementation During Pregnancy Reduce The Risk of Atopic Eczema Among Infants?

In a recent double-blind, randomized, placebo-controlled trial, researchers found a reduced risk of eczema at the age of one year in infants whose mothers took vitamin D supplements during pregnancy.

“The really other interesting thing was that protective effects of the maternal vitamin D supplementation was only significant in those infants who were breastfed for more than 1 month,” lead study author Sarah El-Heis, MRCP, DM told Consultant360 in an exclusive video interview.

There were similar findings at ages two and four years, but the association was weaker, Dr El-Heis told Consultant360.

Previous research on the association between vitamin D supplementation during pregnancy and the likelihood of atopic eczema among the mother’s offspring has been confined to observational studies with inconsistent results.

Enter Dr El-Heis and colleagues who analyzed data from the Maternal Vitamin D Osteoporosis Study (MAVIDOS), a large multicenter trial that involved pregnant women who were randomized to receive 1000 international units (IU) of vitamin D supplement or a matched placebo, from 14 weeks of their gestation to delivery.

A total of 703 mothers and their offspring were examined (352 in the intervention group and 351 in the placebo group). They were assessed by trained research nurses blinded to intervention and control at 12 months (n = 635), 24 months (n = 610), and 48 months (n = 449).

According to the results of the study, the prevalence of atopic eczema in the intervention group at ages 12, 24, and 48 months were 7.2%, 11.4% and 6.7%, respectively, compared with 12%, 14.6%, and 8.4% in the placebo group.

Although Dr El-Heis and colleagues found that the offspring of mothers who received vitamin D daily had a lower odds ratio of atopic eczema at age 12 months, more research is needed to determine why the effect was reduced at 24 and 48 months.

“We still don't know the exact mechanisms by which maternal vitamin D supplementation can impact the infant risk of eczema, but our data has shown that breastfeeding may be one of those mechanisms,” Dr El-Heis told Consultant360.

Although this was a placebo-controlled, double-blind, randomized trial, the study still has some limitations. For example, researchers did not measure for cord blood and offspring 25(OH)D levels, meaning they could examine these when assessing early childhood atopic eczema.

Still, the authors believe their research helps solidify the association between maternal antenatal vitamin D supplementation and the risk of atopic eczema among the mother’s offspring.

“The findings support a developmental influence on atopic eczema, and point to a potentially modifiable perinatal influence on atopic eczema,” the authors conclude.

Want more expert perspective? Watch the full interview with lead author, Sarah El-Heis, MRCP, DM.

Reference

El-Heis S, D'Angelo S, Curtis EM, et al. Maternal antenatal vitamin D supplementation and offspring risk of atopic eczema in the first 4 years of life: evidence from a randomized controlled trial. Br J Dermatol. 2022;187(5):659-666. doi:10.1111/bjd.21721.