Because there is no vaccine for the disease, preventive strategies are needed, investigators from Copenhagen University Hospital in Denmark say.
Children under aged 3 years are less likely to develop croup if their mothers took fish oil and vitamin D supplements during pregnancy, according to the results of a study that will be presented at the European Respiratory Society International Congress.
This was the first large study of its kind to investigate the effects of fish oil and vitamin D supplements on croup.
“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,” Nicklas Brustad, MD, PhD, a clinician working on the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) at Copenhagen University Hospital in Denmark, said in a statement.
“For such purpose, there is evidence that both vitamin D and fish oil could have an influence on the immune system,” he said.
Investigators included 736 pregnant women being cared for by COPSAC from 2010, who were divided into 4 groups.
In 1 group, individuals were given a high-dose vitamin D supplement at 2800 international units per day as well as a fish oil containing long-chain n-3-polyunsaturated fatty acids at 2.4 grams.
Another group was given the high-dose vitamin D supplement and olive oil, while a third group received a standard-dose of vitamin D at 400 international units per day and fish oil.
The last group was given the standard-dose vitamin D and olive oil.
All individuals took the supplements daily from their 24th week of pregnancy until 1 week after their babies were born. The study was also double-blinded, meaning neither the individuals nor investigators knew who was taking which supplement until the end of the study.
Investigators continued to monitor the children until they were aged 3 years, and any who were suspected of suffering from croup were diagnosed by a doctor or via their medical records. In the study, 97 cases of croup were reported among the children.
Overall, investigators found that children whose mothers took the fish oil had an 11% risk for croup compared with 17% for those whose mothers took olive oil. Children whose mothers took a high-dose vitamin D has an 11% risk of croup compared with 18% for those whose mothers took the standard-dose vitamin D.
“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,” Brustad said.
Investigators also plan on studying other potential benefits of vitamin D and fish oil during pregnancy, including its effects on asthma, body composition, bone development, and the central nervous system. They will continue to follow the children in the study and determine why some are more prone to infections in childhood than others.
Fish oil and vitamin D supplements in pregnancy lower the risk of croup in babies and young children. News release. EurekAlert. September 4, 2022. Accessed September 6, 2022. https://www.eurekalert.org/news-releases/963518