Vitamin D during pregnancy helps reduce childhood allergy rate

Vitamin D supplements taken during pregnancy and infancy may help to reduce the high childhood allergy rate, a new study has claimed.
Cameron Grant from the University of Auckland in New Zealand showed for the first time that vitamin D supplements prevent allergy sensitisation to house dust mites in children.
He believes vitamin D supplements may also help prevent asthma developing in young children.
"In our clinical trial of vitamin D supplementation during pregnancy and infancy, we showed that when these supplements were started in the mom at 27 weeks gestation and then continued in her child until the child was six months old, they prevented sensitisation of the child to house dust mites (measured when the child was 18 months old)," he said.

"Based upon a careful review of the records of the children's visits to their family doctor, we also saw that this vitamin D supplementation reduced the proportion of children making primary care visits which their family doctor thought were due to asthma," Grant said.
This is the first study to show that correcting poor vitamin D status during pregnancy and infancy might prevent childhood asthma, he said.

"An interesting aspect is that the effects we saw were measured a year after the vitamin D supplementation was stopped," said Grant.
This implies that vitamin D caused some change in the child's immune system as it was developing in utero and during early infancy which then resulted in differences in the immune response to house dust mites at age 18 months, he said.

Early life events, including those before birth, can influence a baby's later sensitivity to allergens.
"Vitamin D receptors are present on many immune cells and so vitamin D can affect how the immune system works," said Grant.
"In theory maintaining normal vitamin D status when that sensitivity is developing late in pregnancy and early in infancy, could prevent later allergy sensitivity in the child," he added.
The findings were published in the journal Allergy.