Vitamin D deficiency is linked to multiple diseases including psoriasis, chronic kidney disease, diabetes mellitus, asthma, periodontal disease, cardiovascular disease, schizophrenia, depression, and cancer. Now, researchers have shown a correlation between vitamin D deficiency and a higher rate of obstructive sleep apnea (OSA). 

Researchers in Dublin, Ireland reported the higher prevalence of vitamin D deficiency in patients with OSA.  Of the Caucasian adults recruited, 98% of participants with OSA were found to have the deficiency. Polysomnography was used to identify participants with OSA while blood samples were collected to identify participants with vitamin D deficiency. Researchers found that participants with the severe OSA had the greatest vitamin D deficiency. Although the authors pointed out that Dublin sits at high latitude and has limited sunshine, other studies have shown similar findings. Other researchers have also recently found that vitamin D can significantly reduce heart rate. 

Understanding the relationship between vitamin D and sleep apnea is challenging.  Some clinicians believe that low levels of vitamin D can lead to weight gain, and increased weight can in turn increase the risk of OSA. This comes from a theory that vitamin D regulates energy expenditure; however, supplementation studies have not shown vitamin D to significantly decrease weight. Another theory is that OSA is an inflammatory disorder –through an upregulation of inflammatory pathways, vitamin D deficiency predisposes or exacerbates sleep apnea. Perhaps untreated apnea is decreasing the vitamin D stores, as patients treated with CPAP therapy show an increase in vitamin D levels early after treatment.

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Vitamin D is not a treatment for sleep apnea. Given the relationship between vitamin D and OSA, vitamin D levels should be monitored in patients and supplementation encouraged. Vitamin D is inexpensive and easy to obtain. The National Institutes of Health (NIH) recommends 600 IU of vitamin D daily. Sources of vitamin D include fatty fish (such as salmon and tuna) as well as cheese, egg yolks, and fortified cereals and juices. Clinicians should suggest that patients take a walk outside – the body makes vitamin D when exposed to sunshine.

Sharon M. O’Brien, MPAS, PA-C, is a practicing clinician with an interest in helping patients understand the importance of sleep hygiene and the impact of sleep on health.


  1. Kerley CP, Hutchinson K, Bolger K, et al.. Serum vitamin D is significantly inversely associated with disease severity in Caucasian adults with obstructive sleep apnea syndrome. Sleep.  2016;39(2):293–300; doi: 10.5655/sleep.5430 
  2. Vitamin D: Fact sheet for consumers. Bethesda, MD: National Institutes of Health Office of Dietary Supplements. Published June 24, 2011. Accessed March 16, 2016.