Researchers at LSU’s Division of Sleep Medicine conducted a study to determine if there is a cor¬relation between vitamin D deficiency (VitDd) and excessive daytime sleepiness (EDS). 81 sleep clinic patients who complained of sleep problems and nonspecific pain were evaluated. Serum 25-hydroxyvitamin D (25OHD) was measured, and sleepiness was determined using the Epworth Sleepiness Scale score ([ESSs] ESSs ≥ 10’ EDS), and data was correlated using Pearson r. Researchers found that in patients without VitDd, sleepiness scores were inversely correlated with their vitamin D concentration. Among patients with VitDd, sleepi¬ness was directly correlated with serum 25OHD levels in black people, but not among white people. The research suggests that VitDd may contribute to symptoms of sleepiness via known sleep regulating substances, but is also associated with upregulation of NFkB, which functions as a master switch for inflammation and a trigger of the cellular inflammatory cascade resulting from intermittent hypoxia associated with obstructive sleep apnea (OSA), and is also responsible for the regulation of substances that exert homeostatic sleep pres¬sure, such as prostaglandin D2. Therefore, VitDd may not only be a cofactor for the development of cardiovascular morbidity associated with OSA, but may also play a role in the pathogenesis of EDS associated with the disease.
McCarty DE, et al. Vitamin D, Race, and Excessive Daytime Sleepiness. J Clin Sleep Med. Dec 15, 2012; 8(6): 693-697