The effect of vitamin D supplement on the score and quality of sleep

Sleep quality may be directly related with vitamin D serum level. Some studies found that people with lower vitamin D serum level experienced a lower sleep quality. Consequently, this study aimed at determining the effect of vitamin D supplements on sleep score and quality in 20-50 year-old people with sleep disorders.....
https://www.ncbi.nlm.nih.gov/pubmed/28475473