low vitamin D levels don't worsen sleep apnea

Contradicting common perception, researchers have found that low levels of vitamin D, also known as the "sunshine vitamin", does not cause or worsen sleep apnea.

Sleep apnea causes repeated awakenings and pauses in breathing during the night. Obesity appears to contribute to the adverse effects.

"The link between obesity and vitamin D deficiency can be explained a number of ways, one of which is that obese individuals are less likely to be physically active, thereby limiting their sun exposure," said senior investigator Ken Kunisaki, associate professor of medicine at University of Minnesota in the US.

"Although our study was not designed to figure out why obese people have lower vitamin D levels, our results ultimately suggest that low vitamin D levels do not cause or worsen sleep apnea," Kunisaki said. 

The study involved a cohort of 2,827 participants who were generally healthy and elderly males with average age 76.4 years.

"Taking additional vitamin D supplements is not likely to prevent or improve sleep apnea," Kunisaki said.

The researchers also found no evidence to support a link between vitamin D deficiency and increased risk of sleep apnea in non-obese study participants.

The study appeared in the journal Annals of the American Thoracic Society.