The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality .
This association appeared to be non-linear , with progressively lower mortality with increasing 25(OH)D up to a point , beyond which there was no further decrease .
There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases , while for cardiovascular mortality , there is weak evidence of an association in observational studies , which is not supported by the data from intervention or Mendelian r and omization studies .
Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality , but it is unclear whether this is explained by reverse causation , and if there are specific causes of death for which vitamin D might be important .
Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease
BACKGROUND It is unclear whether supplementation with vitamin D reduces the risk of cancer or cardiovascular disease , and data from r and omized trials are limited . METHODS We conducted a nationwide , r and omized , placebo‐controlled trial , with a two‐by‐two factorial design , of vitamin D3 ( cholecalciferol ) at a dose of 2000 IU per day and marine n‐3 ( also called omega‐3 ) fatty acids at a dose of 1 g per day for the prevention of cancer and cardiovascular disease among men 50 years of age or older and women 55 years of age or older in the United States . Primary end points were invasive cancer of any type and major cardiovascular events ( a composite of myocardial infa rct ion , stroke , or death from cardiovascular causes ) . Secondary end points included site‐specific cancers , death from cancer , and additional cardiovascular events . This article reports the results of the comparison of vitamin D with placebo . RESULTS A total of 25,871 participants , including 5106 black participants , underwent r and omization . Supplementation with vitamin D was not associated with a lower risk of either of the primary end points . During a median follow‐up of 5.3 years , cancer was diagnosed in 1617 participants ( 793 in the vitamin D group and 824 in the placebo group ; hazard ratio , 0.96 ; 95 % confidence interval [ CI ] , 0.88 to 1.06 ; P=0.47 ) . A major cardiovascular event occurred in 805 participants ( 396 in the vitamin D group and 409 in the placebo group ; hazard ratio , 0.97 ; 95 % CI , 0.85 to 1.12 ; P=0.69 ) . In the analyses of secondary end points , the hazard ratios were as follows : for death from cancer ( 341 deaths ) , 0.83 ( 95 % CI , 0.67 to 1.02 ) ; for breast cancer , 1.02 ( 95 % CI , 0.79 to 1.31 ) ; for prostate cancer , 0.88 ( 95 % CI , 0.72 to 1.07 ) ; for colorectal cancer , 1.09 ( 95 % CI , 0.73 to 1.62 ) ; for the exp and ed composite end point of major cardiovascular events plus coronary revascularization , 0.96 ( 95 % CI , 0.86 to 1.08 ) ; for myocardial infa rct ion , 0.96 ( 95 % CI , 0.78 to 1.19 ) ; for stroke , 0.95 ( 95 % CI , 0.76 to 1.20 ) ; and for death from cardiovascular causes , 1.11 ( 95 % CI , 0.88 to 1.40 ) . In the analysis of death from any cause ( 978 deaths ) , the hazard ratio was 0.99 ( 95 % CI , 0.87 to 1.12 ) . No excess risks of hypercalcemia or other adverse events were identified . CONCLUSIONS Supplementation with vitamin D did not result in a lower incidence of invasive cancer or cardiovascular events than placebo . ( Funded by the National Institutes of Health and others ; VITAL Clinical Trials.gov number , NCT01169259 .
The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality .
This association appeared to be non-linear , with progressively lower mortality with increasing 25(OH)D up to a point , beyond which there was no further decrease .
There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases , while for cardiovascular mortality , there is weak evidence of an association in observational studies , which is not supported by the data from intervention or Mendelian r and omization studies .
Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality , but it is unclear whether this is explained by reverse causation , and if there are specific causes of death for which vitamin D might be important .