Men who doze off during the day may benefit from salmon, eggs, or a bit more time in the sun, all of which increase vitamin D levels. New data reported by David E. McCarty, MD, and colleagues in the Journal of Clinical Sleep Medicine (2012; 8:693-697) indicate that suboptimal levels of vitamin D are associated with a greater likelihood of excessive daytime sleepiness.

The reasons for these effects on sleepiness are many, including a relationship of vitamin D to obstructive sleep apnea, nonspecific musculoskeletal pain, and known sleep regulating substances such as tumor necrosis factor alfa and prostaglandin D2.  Immune dysregulation is an important consequence of low vitamin D that could lead to excessive daytime sleepiness mediated by components of the inflammatory cascade.

Beyond its effects on bony demineralization, several studies have demonstrated the adverse consequences of vitamin D deficiency on the immune system, pulmonary disease, musculoskeletal pain, metabolic syndrome, hypertension, stress, and cognition.