Until recently, it was controversial whether a vitamin D deficiency in the expectant mother could cause neurodermatitis in the infant. A British study has now been able to show that the additional administration of vitamin D3 during pregnancy significantly reduces the risk of the infant developing atopic dermatitis in the first year of life. 
In areas with little sun, such as Europe, children under the age of 5 are particularly likely to develop neurodermatitis (atopic dermatitis/eczema). In Germany, around 23% of babies and toddlers are affected.  The typical symptoms of the inflammatory skin disease are a red, itchy rash and dry, scaly skin.
With the MAVIDOS study group, researchers from the University of Southampton investigated whether the additional administration of vitamin D3 in the pregnancy the frequency of atopic eczema (neurodermatitis) in offspring. For this purpose, the team recruited 703 pregnant women from the MAVIDOS study (Maternal Vitamin D Osteoporosis Study) and distributed them between the 14th and 17th random week of pregnancy in two groups:
- The 352 women in the intervention group also received 1,000 IU (25 µg) of vitamin D3 daily in the form of a tablet.
- Instead, the 351 women in the control group also received a placebo tablet (without vitamin D3) daily.
Furthermore, all women were allowed to continue to take up to 400 IU (10 µg) of vitamin D3 daily. For comparison: The German Society for Nutrition recommends that pregnant women take in around 800 IU (20 µg) of vitamin D every day if they do not have enough sun exposure .
All participants initially had a 25-OH-vitamin D serum level of 25-100 nmol/l - with values below 30 nmol/l indicating vitamin D deficiency .
Prenatal administration of vitamin D can significantly reduce the risk of neurodermititis in the first year of life
As part of the study, the women were asked about skin symptoms in their offspring after 12, 24 and 48 months of life and the children were examined. In the intervention group with additional vitamin D3 administration, the risk of neurodermatitis in the first 12 months of life was 45% lower than in the control group.
The researchers also found that the mother's breastfeeding behavior is crucial for the protective effect of vitamin D3. The risk of neurodermatitis was reduced by 52% for the first 12 months if a mother (intervention group) was at least one month after the birth still silent. In mothers who breastfed for less than a month, the risk of neurodermatitis was reduced by only 20% - which means that the protective effect of prenatal vitamin D3 was no longer significant. After 24 and 48 months, the protective effect was also no longer significant.
dr El-Heis and her team conclude from their results that adequate vitamin D3 supplementation during pregnancy can help prevent neurodermatitis in infancy.
 El-Heis S, D’Angelo S, Curtis EM, Healy E, Moon RJ, Crozier SR, Inskip H, Cooper C, Harvey NC, Godfrey KM. 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; DOI: 10.1111/bjd.21721