Kids whose moms don't get enough sunshine during pregnancy may be more likely to develop learning difficulties, researchers report.
The finding stems from data on more than 422,000 school-aged children in Scotland. Low levels of exposure to UVB rays -- but not UVA sunlight -- during the entire pregnancy was linked to learning disabilities later on.
Because only UVB rays were implicated, the researchers suspect the effect relates to insufficient vitamin D production.
Exposure to vitamin D in the first trimester of pregnancy is essential for fetal brain development, the researchers said.
The percentage of kids with learning disabilities varied by month of conception. It ranged from nearly 17% among children conceived in July to 21% among those conceived in February, March and April, when exposure to sunlight is less. However, the study could not prove a cause-and-effect relationship.
"Learning disabilities can have profound life-long effects on both the affected child and their family. The importance of our study is that it suggests a possible way to prevent learning disabilities in some children," said lead author Jill Pell, director of the University of Glasgow's Institute of Health and Wellbeing.
"Clinical trials are now needed to confirm whether taking vitamin D supplements during pregnancy could reduce the risk of learning disabilities," she said in a university news release.
The report was published June 27 in the journal Scientific Reports.
For more about vitamins during pregnancy, visit the March of Dimes.