With myopia on the rise worldwide, researchers continue to search for modifiable risk factors. A recent study shows neonatal vitamin D levels aren’t one of them, as they don’t appear to play a role in the later development of the condition.

The case-controlled investigation compared dried blood taken shortly after birth from both myopic and healthy male newborns.

Since the time of year a person is born has been associated with later myopia risk—and neonatal vitamin D status is highly dependent on season of birth due to maternal sun exposure late in gestation—a team of researchers looked into whether prenatal exposure to low levels of vitamin D could factor into visual development and adult visual dysfunction.

The investigators analyzed neonatal vitamin D₃ levels of 457 myopic and 1,280 healthy males from the Danish Conscript Registry. After adjusting for maternal age, maternal ethnicity, maternal and paternal education and season of birth, the researchers found seasonal variation of birth didn’t affect myopia risk, and low neonatal vitamin D₃ levels also didn’t appear to increase the chance of developing the condition.