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 .
Cholecalciferol treatment to reduce blood pressure in older patients with isolated systolic hypertension: the VitDISH randomized controlled trial.
IMPORTANCE Observational data link low 25-hydroxyvitamin D levels to both prevalent blood pressure and incident hypertension . No clinical trial has yet examined the effect of vitamin D supplementation in isolated systolic hypertension , the most common pattern of hypertension in older people . OBJECTIVE To test whether high-dose , intermittent cholecalciferol supplementation lowers blood pressure in older patients with isolated systolic hypertension . DESIGN Parallel group , double-blind , placebo-controlled  r and omized trial . SETTING Primary care clinics and hospital clinics . PARTICIPANTS Patients 70 years and older with isolated systolic hypertension ( supine systolic blood pressure > 140 mm Hg and supine diastolic blood pressure < 90 mm Hg ) and baseline 25-hydroxyvitamin D levels less than 30 ng/mL were r and omized into the trial from June 1 , 2009 , through May 31 , 2011 . INTERVENTIONS A total of 100,000 U of oral cholecalciferol or matching placebo every 3 months for 1 year . MAIN OUTCOMES AND MEASURES Difference in office blood pressure , 24-hour blood pressure , arterial stiffness , endothelial function , cholesterol level , insulin resistance , and b-type natriuretic peptide level during 12 months . RESULTS A total of 159 participants were r and omized ( mean age , 77 years ) .  Mean baseline office systolic blood pressure was 163/78 mm Hg . Mean baseline 25-hydroxyvitamin D level was 18 ng/mL. 25-Hydroxyvitamin D levels increased in the treatment group compared with the placebo group ( + 8 ng/mL at 1 year , P < .001 ) . No significant treatment effect was seen for mean ( 95 % CI ) office blood pressure ( −1 [ −6 to 4]/−2 [ −4 to 1 ] mm Hg at 3 months and 1 [ −2 to 4]/0 [ −2 to 2 ] mm Hg overall treatment effect ) . No significant treatment effect was evident for any of the secondary outcomes ( 24-hour blood pressure , arterial stiffness , endothelial function , cholesterol level , glucose level , and walking distance ) . There was no excess of adverse events in the treatment group , and the total number of falls was nonsignificantly lower in the group receiving vitamin D ( 36 vs 46 , P = .24 ) . CONCLUSIONS AND RELEVANCE Vitamin D supplementation did not improve blood pressure or markers of vascular health in older patients with isolated systolic hypertension . TRIAL REGISTRATION is rct n.org Identifier : IS RCT N92186858
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 .