The fact that most MAs on results from RCTs did not show a beneficial effect does not disprove the hypothesis suggested by observational findings on adverse health outcomes of low 25OHD levels
Background A large number of observational studies have reported harmful effects of low 25-hydroxyvitamin D ( 25OHD ) levels on non-skeletal outcomes .
We performed a systematic quantitative review on characteristics of r and omized clinical trials ( RCTs ) included in meta-analyses ( MAs ) on non-skeletal effects of vitamin D supplementation .
Vitamin D3 enhances mood in healthy subjects during winter
Abstract Mood changes synchronised to the seasons exist on a continuum between individuals , with anxiety and depression increasing during the winter months . An extreme form of seasonality is manifested as the clinical syndrome of seasonal affective disorder ( SAD ) with carbohydrate craving , hypersomnia , lethargy , and changes in circadian rhythms also evident . It has been suggested that seasonality and the symptoms of SAD may be due to changing levels of vitamin D3 , the hormone of sunlight , leading to changes in brain serotonin . Forty-four healthy subjects were given 400 IU , 800 IU , or no vitamin D3 for 5 days during late winter in a r and om double-blind study . Results on a self-report measure showed that vitamin D3 significantly enhanced positive affect and there was some evidence of a reduction in negative affect . Results are discussed in terms of their implication s for seasonality , SAD , serotonin , food preference , sleep , and circadian rhythms
The fact that most MAs on results from RCTs did not show a beneficial effect does not disprove the hypothesis suggested by observational findings on adverse health outcomes of low 25OHD levels
Background A large number of observational studies have reported harmful effects of low 25-hydroxyvitamin D ( 25OHD ) levels on non-skeletal outcomes .
We performed a systematic quantitative review on characteristics of r and omized clinical trials ( RCTs ) included in meta-analyses ( MAs ) on non-skeletal effects of vitamin D supplementation .