Gestational cholecalciferol supplementation reduced atopic eczema prevalence at 12 months although the effect becomes weakened by 24 months
Gestational cholecalciferol supplementation significantly reduces the incidence of atopic eczema in offspring at 12 months although this effect was weakened after 24 and 48 months. This was the main findings of a randomised clinical trial by researchers from Southampton and Oxford, UK.
The prevalence of atopic eczema in children has been estimated to be 15.5% and there is some evidence that supplementing with vitamin D during pregnancy can affect the development of atopic diseases such as asthma and atopic eczema. For example, one study in pregnant women who had high dose gestational cholecalciferol observed a 25% reduced risk of asthma/recurrent wheeze in children at 0 – 3 yrs. In another study, women with vitamin D levels > 75 nmol/l during pregnancy, saw an increased risk of eczema at 9 months and asthma at age 9 years. In contrast, a study in which pregnant women supplemented with either 4000 IU/day or 400 IU/day of vitamin D, found no difference in the incidence of atopic eczema when measured after 3 years. But vitamin D certainly has some role in the management of eczema given the evidence that vitamin D supplementation in children improved winter-related atopic eczema.
With some uncertainty over whether gestational cholecalciferol supplementation would affect the development of atopic eczema, for the present study, the researchers set out to test their hypothesis that supplementing with the vitamin during pregnancy, would reduce the incidence of atopic eczema in offspring. As part of the Maternal Vitamin D Osteoporosis (MAVIDOS) Study which was designed to see if the offspring of mothers supplemented with vitamin D in pregnancy had a higher bone mass at birth, women were randomised to receive cholecalciferol 1000 IU/day or matched placebo, from 14 weeks’ gestation until delivery in addition to standard maternity care. For the study, the prevalence of atopic eczema was determined after 12, 24 and 48 months and logistic regression was used to examine the association between the use of gestational cholecalciferol and the development of atopic eczema with the results adjusted for differences in breast feeding.
Gestational cholecalciferol supplements and atopic eczema
The study randomised 703 women to either 1000 IU/day cholecalciferol (352) or placebo with the mean age of women in the cholecalciferol group being 31 years and 31.1 years in the placebo group.
The prevalence of atopic eczema at 12 months was 7.2% compared to 12% in the placebo group, giving an adjusted odds ratio (OR) of 0.55 (95% CI 0.32 – 0.97, P = 0.04). However, at both 24 (OR = 0.76, 95% CI 0.47 – 1.23) and 48 months (OR = 0.75, 95% CI 0.37 – 1.52) the adjusted odds ratios became non-significant.
When stratifying by breast feeding (up to one month vs longer than 1 month), there was a significant reduction in the odds of developing atopic eczema among children breast fed for longer than a month (OR = 0.48, 95% CI 0.24 – 0.93, P = 0.03). Nevertheless, the odds became non-significant at both 24 and 48 months.
The authors concluded that their study provided evidence for a protective effect of gestational cholecalciferol supplementation on the development of atopic eczema and could therefore become a modifiable perinatal factor.
Citation
El-Heis S et al. Maternal antenatal vitamin D supplementation and offspring risk of atopic eczema in the first 4 years of life: evidence from a randomised controlled trial Br J Dermatol 2022
