Study is first to find significant link between sleepiness and vitamin D

A new study suggests that there is a significant correlation between excessive daytime sleepiness and vitamin D, and race plays an important factor.

Results show that in patients with normal vitamin D levels, progressively higher levels of daytime sleepiness were correlated inversely with progressively lower levels of vitamin D. Among patients with , sleepiness and vitamin D levels were associated only among black patients. Surprisingly, this correlation was observed in a direct relationship, with higher vitamin D levels associated with a higher level of sleepiness among black patients.

"While we found a significant correlation between vitamin D and sleepiness, the relationship appears to be more complex than we had originally thought," said David McCarty, MD, the study's principal investigator. "It's important to now do a follow-up study and look deeper into this correlation."

The study, appearing online in the Dec. 15 issue of the Journal of Clinical , involved a consecutive series of 81 sleep clinic patients who complained of and nonspecific pain. All patients eventually were diagnosed with a sleep disorder, which in the majority of cases was obstructive sleep apnea. Vitamin D level was measured by blood sampling, and sleepiness was determined using the Epworth Sleepiness Scale.

According to the authors, this is the first study to demonstrate a significant relationship between sleepiness and vitamin D. They noted that it is logical for race to affect this relationship because increased is an established risk factor for low vitamin D.

The study was not designed to examine causality. However, the authors' previous and current research suggests that suboptimal levels of vitamin D may cause or contribute to , either directly or by means of chronic pain.

More information: "Vitamin D, Race, and Excessive Daytime Sleepiness", Journal of Clinical Sleep Medicine, 2012.

Related Stories

Recommended for you

Breastfeeding protects against environmental pollution

date 20 hours ago

Living in a city with a high level of vehicle traffic or close to a steel works means living with two intense sources of environmental pollution. However, a study conducted by the UPV/EHU researcher Aitana ...

When it comes to hearing, diet may trump noise exposure

date 21 hours ago

Although the old wives' tale about carrots being good for your eyesight has been debunked, University of Florida researchers have found a link between healthy eating and another of your five senses: hearing.

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

jshloram
Dec 15, 2012
The first paragraph of this story is convoluted and very difficult to understand.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.