Taking fish oils and vitamin D in pregnancy lowers risk of croup, study finds

Supplements may ‘stimulate the immune system to help babies and young children clear infections more effectively’

Babies and toddlers are less likely to develop croup if their mothers took fish oils and vitamin D supplements during pregnancy, a new study suggests.

Croup is a common viral chest infection that affects young children’s airways. Symptoms of the condition include a “barking” cough, a hoarse voice and difficulty breathing.

It is commonly a mild condition, but some children may need hospital treatment and breathing support. The NHS recommends all parents call 111 if they suspect their child has croup.

New research presented at the European Respiratory Society International Congress in Barcelona, Spain, found that children of mothers who took fish oils during pregnancy had a 38 per cent less likelihood of developing croup than of those who took olive oil.

The study, led by Dr Nicklas Brustad of the Copenhagen University Hospital, observed 739 women who were pregnant in 2010.

The women were divided into four groups and given supplements daily from their 24^th week of pregnancy.

One group received a high–dose vitamin D supplement and fish oil, another was given high-dose vitamin D and olive oil, the third were given standard-dose vitamin D and fish oil, and the final group took standard-dose vitamin D and olive oil.

The women’s children were monitored until three years old, during which time 97 cases of croup were diagnosed among the group.

Children whose mothers took the fish oil were found to have an 11 per cent risk of developing croup, compared to 17 per cent in those whose mothers took olive oil.

Similarly, in mothers who took high-dose vitamin D, children had an 11 per cent risk of croup, while those from mothers who took the standard dose had an 18 per cent risk of the illness.

Croup typically affects young children (Getty Images/iStockphoto)

Commenting on the findings, Brustad said: “There is currently no vaccine against the pathogen that causes this disease. Therefore, other preventive strategies are needed, and measures initiated during pregnancy might be important since croup occurs in babies and young children.

“Our findings suggest that vitamin D and fish oil could be beneficial against childhood croup in sufficiently high doses. These are relatively cheap supplements meaning that this could be a very cost-effective approach to improving young children’s health.”

The researchers said it is unclear why vitamin D and fish oils have this beneficial effect, but “it could be that they can stimulate the immune system to help babies and young children clear infections more effectively”.

Professor Rory Morty, chair of European Respiratory Society’s lung and airway developmental biology group, who was not involved in the research, said further research was needed to determine whether health services should implement new supplement recommdations in pregnancy.

“We know that lung health in babies and young children can be influenced during pregnancy. For example, babies whose mothers smoke tend to have worse lung health. We are increasingly seeing that elements of a mother’s diet can also help or hinder a baby’s lung development,” Morty said.

“Pregnant women should always speak to their doctor before taking supplements.”