As winter rolls around, so does that “barking-seal” cough that so many parents dread.

Croup, often brought on by a virus like the common cold or RSV, refers to the inflammation of baby’s larynx, trachea and bronchial tubes, which partially blocks baby’s upper airway. This partial blockage is what creates that familiar barking cough and wheezing.

Most commonly seen in kids between 6 months and 3 years old, croup is usually mild, but some children will need hospital treatment and breathing support. As most parents use simple home remedies to ease baby’s symptoms, little has been done to cut down on croup cases—until now

A new study from the Copenhagen University Hospital in Denmark has discovered that when women took high doses of fish oil and vitamin D supplements during pregnancy, their babies had around a 40 percent lower risk of developing croup.

Over 700 pregnant women participated in the study and were split into four groups. One group was given a high-dose vitamin D supplement and fish oil, The second high-dose vitamin D and olive oil, the third standard-dose vitamin D and fish oil, and the final group was given standard-dose vitamin D and olive oil.

All the women took the supplements daily from their 24th week of pregnancy until one week after their babies were born. After watching the children for three years, 97 developed croup. Overall, kids whose moms took fish oil and kids whose moms took high-dose vitamin D had a 38 and 40 percent lower risk, respectively, of developing croup than their counterparts.

“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,” study author Nicklas Brustad, MD, said in a press release discussing the study’s results.

While researchers aren’t quite sure how these prenatal supplements work to fight off croup, they believe it could be because both vitamin D and fish oil stimulate the immune system to help babies and toddlers clear infections more effectively.

Confused about what prenatal supplements might be best for baby? Check out this article on how to choose the best prenatal vitamins for you. Just make sure to speak to your doctor before starting any new supplements.

OB-GYN & Prenatal Care