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 .
Therapeutic effects of vitamin D as adjunctive therapy to fluoxetine in patients with major depressive disorder
Objective : To compare the therapeutic effects of vitamin D3 plus fluoxetine and fluoxetine alone in patients with major depressive disorder . Methods : In the present double-blind , r and omized , placebo-controlled trial , 42 patients with a diagnosis of major depressive disorder based on DSM-IV criteria were r and omly assigned into two groups to receive daily either 1500 IU vitamin D3 plus 20 mg fluoxetine or fluoxetine alone for 8 weeks . Depression severity was assessed at 2-week intervals using the 24-item Hamilton Depression Rating Scale ( HDRS ) as a primary outcome measure and the 21-item Beck Depression Inventory ( BDI ) as a secondary outcome measure . Serum 25(OH ) vitamin D was measured at baseline and after intervention . Results : Forty patients completed the trial . A two-way repeated- measures analysis of variance showed that depression severity based on HDRS and BDI decreased significantly after intervention , with a significant difference between the two groups . The vitamin D + fluoxetine combination was significantly better than fluoxetine alone from the fourth week of treatment . Conclusions : In the present 8-week trial , the vitamin D + fluoxetine combination was superior to fluoxetine alone in controlling depressive symptoms
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 .