Vitamin D deficiency: A forgotten aspect in sleep disorders? A critical update.

Over the past few years, there has been a surge in interest regarding the connection between sleep duration and quality, sleep disorders, mainly Obstructive sleep apnoea (OSA) and Vitamin D. There is growing evidence to support a new role of Vitamin D in the maintenance and regulation of optimal sleep. Furthermore, a notable link has been identified between OSA and a decrease in serum Vitamin D levels, which appears to intensify as the severity of sleep apnea worsens. Vitamin D status could also potentially serve as a mediator or provide an explanation for the association between OSA and cardiometabolic morbidity, but the current state of research in this area is inadequate. Studies have indicated that the supplementation of Vitamin D can optimize sleep quality, presenting more proof of the connection between insufficient vitamin D levels and sleep disorders. However, it is unclear whether low serum Vitamin D levels are a contributing factor to OSA development or if OSA predisposes individuals to Vitamin D deficiency. As a result, various studies have endeavored to examine the complex relationship between OSA and Vitamin D deficiency. In children and adolescents, while data is limited, there seems also to be a link between sleep disorders and Vitamin D levels. Therefore, the objective of this review is to provide a comprehensive overview of the current evidence on the association between Vitamin D and sleep disorders in both adults and children. • Increasing evidence suggests a new role of vitamin D in the maintenance and regulation of optimal sleep. • OSA presence has been linked to lower serum Vitamin D levels, especially as the severity of OSA progresses. • In children and adolescents, despite the scarcity of data, an association between OSA and Vitamin D levels is also apparent. • Vitamin D status may potentially mediate or elucidate the association between OSA and cardiometabolic morbidity. • It remains uncertain whether vitamin D deficiency increases OSA risk, or if OSA itself predisposes to Vitamin D deficiency. [ABSTRACT FROM AUTHOR]