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 .
Correlation of symptoms with vitamin D deficiency and symptom response to cholecalciferol treatment: a randomized controlled trial.
OBJECTIVE To examine the association of symptoms with vitamin D deficiency and symptom response to cholecalciferol treatment in a r and omized , double-blind , placebo-controlled trial . METHODS Adult primary care patients in Duluth , Minnesota , were screened for vitamin D deficiency in February 2007 . Participants completed question naires pertaining to a variety of symptoms , vitamin D intake , and selected medical conditions . Patients with mild to moderate vitamin D deficiency ( 25-hydroxyvitamin D [ 25(OH)D ] , 10 - 25 ng/mL ) participated in a r and omized controlled trial ( RCT ) of vitamin D replacement and its effect on symptoms . Participants were r and omly assigned to receive 50 000 units of cholecalciferol ( vitamin D3 ) weekly or placebo for 8 weeks . Patients with severe vitamin D deficiency ( 25[OH]D < 10 ng/mL ) were treated in an unblinded fashion , and symptoms were reevaluated post treatment . RESULTS A total of 610 patients underwent initial screening , and 100 patients with mild to moderate vitamin D deficiency participated in the RCT . Thirty-eight severely deficient patients were treated in an unblinded fashion . On initial screening , 46.2 % of participants were deficient in vitamin D. Self-reported vitamin D supplementation , milk intake , celiac disease , gastric bypass , and chronic pancreatitis were predictive of vitamin D status . Severely deficient participants reported increased musculoskeletal symptoms , depression ( including seasonal ) , and higher ( worse ) scores on a fibromyalgia assessment question naire . In the RCT , the treated group showed significant improvement in fibromyalgia assessment scores ( P = 0.03 ) , whereas the placebo-treated participants did not . Severely deficient patients did not show symptom improvement over the 8-week trial period or when followed up 1 year later . CONCLUSIONS Compared with participants in the placebo group , patients in the treatment group showed mild short-term improvement in the overall fibromyalgia impact score , but did not show significant improvement in most musculoskeletal symptoms or in activities of daily living
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 .