There is currently no firm evidence that vitamin D supplementation decreases or increases cancer occurrence in predominantly elderly community-dwelling women .
Vitamin D₃ supplementation  decreased cancer mortality  and vitamin D supplementation  decreased all-cause mortality , but these estimates are at risk of type I errors due to the fact that too few participants were examined , and to risks of attrition bias originating from substantial dropout of participants .
Combined vitamin D₃ and calcium supplements  increased nephrolithiasis , whereas it remains unclear from the included trials whether vitamin D₃ , calcium , or both were responsible for this effect .
BACKGROUND The evidence on whether vitamin D supplementation is effective in decreasing cancers is contradictory .
OBJECTIVES To assess the beneficial and harmful effects of vitamin D supplementation for prevention of cancer in adults .
Annual high-dose vitamin D3 and mental well-being: randomised controlled trial.
BACKGROUND Epidemiological evidence supports a relationship between vitamin D and mental well-being , although evidence from large-scale placebo-controlled intervention trials is lacking . AIMS To examine if vitamin D supplementation has a beneficial effect on mood in community-dwelling older women ; if a single annual large dose of vitamin D has a role in the prevention of depressive symptoms ; and if there is an association between serum 25-hydroxyvitamin D levels and mental health . METHOD A double-blind , r and omised , placebo-controlled trial of women aged 70 or older ( the Vital D Study : IS RCT N83409867 and ACTR12605000658617 ) . Participants were r and omly assigned to receive 500 000 IU vitamin D(3 ) ( cholecalciferol ) orally or placebo every autumn/winter for 3 - 5 consecutive years . The tools utilised at various time points were the General Health Question naire , the 12-item Short Form Health Survey , the Patient Global Impression-Improvement scale and the WHO Well-Being Index . Serum 25-hydroxyvitamin D levels were measured in a subset of 102 participants . RESULTS In this non- clinical population , no significant differences between the vitamin D and placebo groups were detected in any of the measured outcomes of mental health . Serum 25-hydroxyvitamin D levels in the vitamin D group were 41 % higher than the placebo group 12 months following their annual dose . Despite this difference , scores from the question naires did not differ . Furthermore , there was no interaction between those on antidepressant/anxiety medication at baseline and the treatment groups . CONCLUSIONS The lack of improvement in indices of mental well-being in the vitamin D group does not support the hypothesis that an annual high dose of vitamin D(3 ) is a practical intervention to prevent depressive symptoms in older community-dwelling women
There is currently no firm evidence that vitamin D supplementation decreases or increases cancer occurrence in predominantly elderly community-dwelling women .
Vitamin D₃ supplementation  decreased cancer mortality  and vitamin D supplementation  decreased all-cause mortality , but these estimates are at risk of type I errors due to the fact that too few participants were examined , and to risks of attrition bias originating from substantial dropout of participants .
Combined vitamin D₃ and calcium supplements  increased nephrolithiasis , whereas it remains unclear from the included trials whether vitamin D₃ , calcium , or both were responsible for this effect .
BACKGROUND The evidence on whether vitamin D supplementation is effective in decreasing cancers is contradictory .
OBJECTIVES To assess the beneficial and harmful effects of vitamin D supplementation for prevention of cancer in adults .