Lower vitamin D levels do not increase severity of obstructive sleep apnea

A recent study of elderly men found no evidence that obstructive sleep apnea (OSA) increased in severity (or prevalence) as a result of vitamin D deficiency.

The research, published online ahead of print in the Annals of the American Thoracic Society, had set out to address a gap in the literature based on inconsistencies in studies exploring the potential association between lower vitamin D levels and OSA, a disease of recurrent, partial or complete upper airway closure during sleep. The researchers, who analyzed data from a large multi-center cohort study, found that low levels of vitamin D were a marker of larger body mass index (BMI) and neck circumference, but were not likely to predict OSA.

"The link between obesity and vitamin D deficiency can be explained a number 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, MD, MS, Medical Director of the Sleep Apnea Program at the Minneapolis VA and Associate Professor of Medicine at the University of Minnesota. "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 OSA," said Kunisaki. "Therefore, taking additional vitamin D supplements is not likely to prevent or improve OSA."

The researchers also found no evidence to support a link between vitamin D deficiency and increased risk of OSA in non-obese study participants.
The researchers noted that the cohort of 2,827 participants whose data were analyzed in this study were generally healthy, mostly Caucasian (92.2%), elderly males (average age 76.4 years), therefore limiting the generalizability of the study results to other populations.