- The shortwave ultraviolet exposure has been found to be associated with a higher risk of learning disabilities.
- Researchers conducted the study on 422,512 schoolchildren from across Scotland.
- About 19% (79,616) of them had a learning disability.
Learning disabilities have intense, long-lasting effects on affected people and their families. According to the National Institutes of Health, 15% of the United States population has some type of learning disability.
Recently, researchers at the University of Glasgow in Scotland conducted a study on more than 422,000 school-age children and found that too little exposure of sunlight during pregnancy was linked to a higher risk of learning disabilities.
During pregnancy, the fetus grows rapidly and becomes vulnerable to environmental exposures. The shortwave ultraviolet exposure (UVB), in particular, has been found to be associated with a greater risk of learning disabilities.
While UVA (longwave ultraviolet) and UVB are correlated, there is a significant variation to determine if the association with solar radiation are driven by UVB or UVA. The team investigated whether overall ultraviolet radiation was linked with learning disabilities before analyzing UVB specifically.
UVB rays play an important role in producing vitamin D in the body, which is essential for bone-strengthening and normal brain development. However, too much exposure has its own health risks.
In order to explore the link between UVB exposure and learning disability, researchers analyzed Scotland-wide education, maternity records, as well as satellite data. They linked routinely collected educational and health data with environmental data.
Reference: Nature | DOI:10.1038/s41598-019-45562-9 | University of Glasgow
Doing so, they found a strong relationship between lower UVB exposure [over the entire pregnancy period] and learning disabilities. The early stages of pregnancy, in particular, are more vulnerable to the consequences of little sunlight.
Although the underlying mechanism isn’t well-understood, vitamin D is usually deficient over winter in high latitude countries (like Scotland) due to insufficient UVB.
Crude prevalence of learning disabilities by month of conception
Researchers conducted the study on 422,512 children: about 19% (79,616) of them had a learning disability. This figure varied by month of conception: nearly 21% of children conceived in February, March, and April, had learning disabilities.
Read: Babies Born To Older Fathers Have Higher Risk of Adverse Birth Outcomes
The study also suggests potential ways to prevent learning disabilities in schoolchildren.
Further investigation and clinical trials are required to validate this hypothesis and verify whether taking vitamin D supplements during pregnancy could decrease the risk of learning disabilities.
