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 .
Effects of Vitamin D Supplementation on Cognitive and Emotional Functioning in Young Adults – A Randomised Controlled Trial
Background Epidemiological research links vitamin D status to various brain-related outcomes . However , few trials examine whether supplementation can improve such outcomes and none have examined effects on cognition . This study examined whether Vitamin D supplementation led to improvements in diverse measures of cognitive and emotional functioning , and hypothesised that supplementation would lead to improvements in these outcomes compared to placebo . Methods /Principal Findings Healthy young adults were recruited to a parallel-arm , double-blind trial conducted at The University of Queensl and . Participants were r and omly allocated to receive Vitamin D ( one capsule daily , containing 5000 IU cholecalciferol ) or identical placebo capsule for six weeks . All participants and outcome assessors were blinded to group assignment . Primary outcome measures assessed at baseline and 6 weeks were working memory , response inhibition and cognitive flexibility . Secondary outcomes were : hallucination-proneness , psychotic-like experiences , and ratings of depression , anxiety and anger .  128 participants were recruited , r and omised and included in primary analyses ( vitamin D n = 63 ; placebo n = 65 ) . Despite significant increases in vitamin D status in the active group , no significant changes were observed in working memory ( F = 1.09 ; p = 0.30 ) , response inhibition ( F = 0.82 ; p = 0.37 ) , cognitive flexibility ( F = 1.37 ; p = 0.24 ) or secondary outcomes . No serious adverse effects were reported . Conclusions Our findings indicate that vitamin D supplementation does not influence cognitive or emotional functioning in healthy young adults . Future controlled trials in targeted population s of interest are required to determine whether supplementation can improve functioning in these domains . Australian and New Zeal and Clinical Trials Registry ; ACTRN12610000318088
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 .