A multi-ethnic study has shown that vitamin D supplements can benefit sleep, particularly in African Americans, as reported by the Clinical Advisor.
Through blood analysis, the researchers found that 34.6% of the participants in their study were vitamin D deficient and 30.9% had insufficient levels of vitamin D. Those with lower vitamin D levels tended to be younger and African-American. Participants with lower vitamin D levels also had higher mean waist circumferences, higher depression scores, and increased rates of smoking and asthma.
Polysomnography and actigraphy demonstrated that participants with vitamin D deficiencies had shorter sleeper duration, less REM sleep, and higher scores on the Epworth Sleepiness Scale. In African-Americans, low vitamin D levels were significantly associated with shorter average sleep duration. There was no association between vitamin D levels and sleep duration with other races and ethnicities. Why the difference between races? While the answer is unclear, it may be due to differences in metabolism, receptor activity, and activation of vitamin D.