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 .
Effect of treatment with dydrogesterone or calcium plus vitamin D on the severity of premenstrual syndrome.
OBJECTIVE To compare the effects of dydrogesterone and calcium plus vitamin D in women with severe premenstrual syndrome ( PMS ) . METHOD In this r and omized , double-blind , placebo-controlled study , 180 Shiraz University students with PMS used question naires daily to rate their symptoms for 2 menstrual cycles . Then , the students were r and omly assigned to take a tablet containing either 5 mg of dydrogesterone , 500 mg of calcium plus 200 mg of vitamin D , or a placebo twice daily from the 15th to the 24th day of the cycle for 2 more cycles , and to use the same question naires during the intervention cycles . The collected data were then analyzed by repeated-measurement design and multilevel modeling tests . RESULT Treatment with dydrogesterone or calcium plus vitamin D  decreased symptom severity in a similar way ( by 4.64 % and 4.20 % , respectively ) and placebo was associated with a 3.42 % decrease . CONCLUSION Treatment with dydrogesterone or calcium plus vitamin D had a similar effect on symptom severity in women with PMS
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 .