The evidence shows that vitamin D supplementation provides some benefit in fracture prevention ( likely ∼10–15 % relative reduction ) , particularly at a dose ≥800 IU and with calcium ; a likely benefit in the rate of falls , though it is less clear whether the number of fallers changes ; and a possible small ( ∼5 % ) relative reduction in mortality .
Evidence does not support the use of vitamin D supplementation for the prevention of cancer , respiratory infections or rheumatoid arthritis .
Similarly , evidence does not support vitamin D supplementation for the treatment of multiple sclerosis and rheumatoid arthritis or for improving depression/mental well-being .
Regular testing of 25-hydroxyvitamin D is generally not required , and mega-doses ( ≥300,000 IU ) appear to increase harms .
Over the past decade , a large body of observational evidence has suggested an association between  lower vitamin D status ( 25-hydroxyvitamin D ) and multiple acute and chronic disorders , including cancer , multiple sclerosis , depression and respiratory tract infections .
This evidence has fostered the hypothesis that increasing vitamin D intake may treat and prevent such disorders .
Our objective was to perform a critical analysis of the highest-level evidence for ten common beliefs regarding vitamin D for the prevention of falls , fractures and respiratory tract infections , the reduction of cancer incidence/mortality and overall mortality , and the prevention or treatment of depression/mental well-being , rheumatoid arthritis and multiple sclerosis , as well as maximum dosing and regular testing .
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 evidence shows that vitamin D supplementation provides some benefit in fracture prevention ( likely ∼10–15 % relative reduction ) , particularly at a dose ≥800 IU and with calcium ; a likely benefit in the rate of falls , though it is less clear whether the number of fallers changes ; and a possible small ( ∼5 % ) relative reduction in mortality .
Evidence does not support the use of vitamin D supplementation for the prevention of cancer , respiratory infections or rheumatoid arthritis .
Similarly , evidence does not support vitamin D supplementation for the treatment of multiple sclerosis and rheumatoid arthritis or for improving depression/mental well-being .
Regular testing of 25-hydroxyvitamin D is generally not required , and mega-doses ( ≥300,000 IU ) appear to increase harms .
Over the past decade , a large body of observational evidence has suggested an association between  lower vitamin D status ( 25-hydroxyvitamin D ) and multiple acute and chronic disorders , including cancer , multiple sclerosis , depression and respiratory tract infections .
This evidence has fostered the hypothesis that increasing vitamin D intake may treat and prevent such disorders .
Our objective was to perform a critical analysis of the highest-level evidence for ten common beliefs regarding vitamin D for the prevention of falls , fractures and respiratory tract infections , the reduction of cancer incidence/mortality and overall mortality , and the prevention or treatment of depression/mental well-being , rheumatoid arthritis and multiple sclerosis , as well as maximum dosing and regular testing .