Is obstructive sleep apnea linked to low levels of vitamin D?
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 link between vitamin D deficiency and obstructive sleep apnea can be challenging
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.
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.
References
- 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
- Vitamin D: Fact sheet for consumers. Bethesda, MD: National Institutes of Health Office of Dietary Supplements. Published June 24, 2011. Accessed March 16, 2016.
