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 .
Can vitamin D supplementation prevent winter-time blues? A randomised trial among older women.
BACKGROUND Seasonal Affective Disorder ( SAD ) is a sub-type of depression that only occurs during the winter months . A reduction in vitamin D may be linked to SAD . Since vitamin D deficiency has been reported to be common in older people , vitamin D supplementation may be expected to reduce seasonal mood disturbance in this group . OBJECTIVE To assess the effect of vitamin D supplementation on the mental health of older women . SETTING Primary care in three areas of the UK ( Herts , Newcastle , York ) . SUBJECTS Women aged 70 years or more recruited to the trial in the months May-October . INTERVENTION Eligible women were r and omised to receive calcium and vitamin D supplementation or no supplementation . OUTCOME MEASURE At baseline and the six monthly assessment the mental component score ( MCS ) , calculated from the SF-12 question naire was used to assess participants ' subjective psychological well-being . RESULTS A total of 2117 women recruited to the trial had their baseline measures taken between the months of May-October ( 1205 woman in the control group and 912 women in the intervention group ) . Of these women , 1621 had a  MCS score at baseline and six months . Comparison of the six month mean MCS scores , adjusting for baseline MCS score and age , showed there was no significant difference between the two scores ( p = 0.262 ) . CONCLUSIONS Supplementing elderly women with 800 IU of vitamin D daily did not lead to an improvement in mental health scores
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 .