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 vitamin D on all-cause mortality in heart failure (EVITA): a 3-year randomized clinical trial with 4000 IU vitamin D daily
Aims Circulating 25-hydroxyvitamin D ( 25OHD ) levels < 75 nmol/L are associated with a nonlinear increase in mortality risk . Such 25OHD levels are common in heart failure ( HF ) . We therefore examined whether oral vitamin D supplementation reduces mortality in patients with advanced HF . Methods and results Four hundred HF patients with 25OHD levels < 75 nmol/L were r and omized to receive 4000 IU vitamin D daily or matching placebo for 3 years . Primary endpoint was all-cause mortality . Key secondary outcome measures included hospitalization , resuscitation , mechanical circulatory support ( MCS ) implant , high urgent listing for heart transplantation , heart transplantation , and hypercalcaemia . Initial 25OHD levels were on average < 40 nmol/L , remained around 40 nmol/L in patients assigned to placebo and plateaued around 100 nmol/L in patients assigned to vitamin D. Mortality was not different in patients receiving vitamin D ( 19.6 % ; n = 39 ) or placebo ( 17.9 % ; n = 36 ) with a hazard ratio ( HR ) of 1.09 [ 95 % confidence interval ( CI ) : 0.69 - 1.71 ; P = 0.726 ] . The need for MCS implant was however greater in patients assigned to vitamin D ( 15.4 % , n = 28 ) vs. placebo [ 9.0 % , n = 15 ; HR : 1.96 ( 95 % CI : 1.04 - 3.66 ) ; P = 0.031 ] . Other secondary clinical endpoints were similar between groups . The incidence of hypercalcaemia was 6.2 % ( n = 10 ) and 3.1 % ( n = 5 ) in patients receiving vitamin D or placebo ( P = 0.192 ) . Conclusion A daily vitamin D dose of 4000 IU did not reduce mortality in patients with advanced HF but was associated with a greater need for MCS implants . Data indicate caution regarding long-term supplementation with moderately high vitamin D doses . Trial Registration Information clinical trials.gov Idenitfier : NCT01326650
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 .