Issue Navigator

Volume 11 No. 11
Earn CME
Accepted Papers

Letters to the Editor

Vitamin D and Sleep Apnea: Beyond a Simple Association

Daniela Leite de Oliveira, BsC; Camila Hirotsu, PhD; Sergio Tufik, MD, PhD; Monica Levy Andersen, PhD
Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil

We would like to praise Dr. Liguori and colleagues for their elegant study showing that the use of continuous positive airway pressure (CPAP) for one week is able to revert vitamin D deficit in men.1 Recent studies have demonstrated that vitamin D deficiency has been associated with sleep disorders in different populations.2 Even being highly discussed, there are few studies relating its function to sleep.3

Currently due to the modern lifestyle, the population has remained indoors, preventing the sunlight exposure needed for the synthesis of the vitamin D precursor. It has been demonstrated that staying most of the time indoors can alter the cortisol and melatonin levels, causing a disturbance in the sleep-wake cycle.4 It is important to emphasize that in the current study the absence of clinical information related to the groups could be a bias. Vitamin D deficiency is associated with obesity, as well as weight reduction is correlated with increased serum levels of cholecalciferol.5 Thus, the increase in vitamin D levels found in male patients after the treatment with CPAP could possibly be linked to weight loss.

Another point to be considered is ethnicity. It is known that in Afro-descendent individuals with dark skin, solar exposure time must be greater for a suitable endogenous synthesis of vitamin D. They present vitamin D deficiency more frequently than other people, as well as daytime sleepiness index is higher.6 Therefore, OSA individuals with different ethnic groups could require different time of CPAP treatment to achieve the same effect on the concentrations of vitamin D.

As a perspective, we would like to emphasize the importance of evaluating the inter-individual variability. There is evidence showing that the presence of polymorphisms in the vitamin D receptor gene is associated with vitamin D deficit.7 Finally, we congratulate the authors for their work and expect that these results may help developing the research in this line, allowing a better understanding of vitamin D metabolism and its regulatory mechanisms associated with sleep.


Studies are supported by fellowship from the Associação Fundo de Incentivo à Pesquisa (AFIP) and the São Paulo Research Foundation (grant #2014/15259-2 to CH). ST and MLA received CNPq Fellowships. The authors have indicated no financial conflicts of interest.


de Oliveira DL, Hirotsu C, Tufik S, Andersen ML. Vitamin D and sleep apnea: beyond a simple association. J Clin Sleep Med 2015;11(11):1345.



Liguori C, Romigi A, Izzi F, et al., authors. Continuous positive airway pressure treatment increases serum vitamin D levels in male patients with obstructive sleep apnea. J Clin Sleep Med. 2015;11:603–7. [PubMed]


McCarty DE, Chesson AL Jr, Jain SK, Marino AA, authors. The link between vitamin D metabolism and sleep medicine. Sleep Med Rev. 2014;18:311–9. [PubMed]


Harb F, Hidalgo MP, Martau B, authors. Lack of exposure to natural light in the workspace is associated with physiological, sleep and depressive symptoms. Chronobiol Int. 2015;32:368–75. [PubMed]


Andersen ML, Tufi k S, authors. Vitamin D as an underlying factor in sleep-related issues. J Clin Sleep Med. 2012;8:699. [PubMed Central][PubMed]


Slusher AL, McAllister MJ, Huang CJ, authors. A therapeutic role for vitamin D on obesity-associated infl ammation and weight-loss intervention. Infl amm Res. 2015;64:565–75.


McCarty DE, Reddy A, Keigley Q, Kim PY, Marino AA, authors. Vitamin D, race, and excessive daytime sleepiness. J Clin Sleep Med. 2012;8:693–7. [PubMed Central][PubMed]


Berlanga-Taylor AJ, Knight JC, authors. An integrated approach to defi ning genetic and environmental determinants for major clinical outcomes involving vitamin D. Mol Diagn Ther. 2014;18:261–72. [PubMed Central][PubMed]