What gives off vitamin d

These participants were randomized to take 25 mcg 1, IU vitamin D 3, 1, mg calcium, both supplements, or a placebo daily for 3—5 years, followed by an additional 3—5 years of observation after participants stopped the treatment.

Vitamin D alone did not significantly affect the development of new serrated polyps, but the combination of vitamin D with calcium increased the risk almost fourfold. The VITAL trial found no association between vitamin D supplementation and the risk of colorectal adenomas or serrated polyps [ ].

Lung cancer A study of cohorts that included 5, participants who developed lung cancer and 5, matched controls found no association between serum 25 OH D levels and risk of subsequent lung cancer, even when the investigators analyzed the data by sex, age, race and ethnicity, and smoking status [ ]. Pancreatic cancer One study comparing men who developed pancreatic cancer to matched controls found no relationship between serum 25 OH D levels and risk of pancreatic cancer [ ].

Another study that compared male smokers in Finland with pancreatic cancer to matched controls found that participants in the highest quintile of 25 OH D levels more than Prostate cancer Research to date provides mixed evidence on whether levels of 25 OH D are associated with the development of prostate cancer.

Several studies published in suggested that high levels of 25 OH D might increase the risk of prostate cancer. This U-shaped association was most pronounced for men with the most aggressive forms of prostate cancer. A case-control analysis of 1, cases of prostate cancer and 1, controls found no associations between 25 OH D levels and prostate cancer risk [ ].

What gives off vitamin d

Since , however, several published studies and meta-analyses have found no relationship between 25 OH D levels and prostate cancer risk [ , ]. For example, an analysis was conducted of 19 prospective studies that provided data on prediagnostic levels of 25 OH D for 13, men who developed prostate cancer and 20, control participants [ ]. Vitamin D deficiency or insufficiency did not increase the risk of prostate cancer, and higher 25 OH D concentrations were not associated with a lower risk.

Several studies have examined whether levels of 25 OH D in men with prostate cancer are associated with a lower risk of death from the disease or from any cause. One study included 1, men treated for prostate cancer whose plasma 25 OH D levels were measured 4. Among the participants who died 41 deaths were due to prostate cancer, 25 OH D levels were not associated with risk of death from prostate cancer or any cause [ ].

However, a meta-analysis of 7 cohort studies that included 7, men with prostate cancer found higher 25 OH D levels to be significantly associated with lower mortality rates from prostate cancer or any other cause [ ]. For men with prostate cancer, whether vitamin D supplementation lengthens cancer-related survival is not clear. Conclusions about vitamin D and cancer The USPSTF stated that, due to insufficient evidence, it was unable to assess the balance of benefits and harms of supplemental vitamin D to prevent cancer [ ].

Taken together, studies to date do not indicate that vitamin D with or without calcium supplementation reduces the incidence of cancer, but adequate or higher 25 OH D levels might reduce cancer mortality rates. Further research is needed to determine whether vitamin D inadequacy increases cancer risk, whether greater exposure to the nutrient can prevent cancer, and whether some individuals could have an increased risk of cancer because of their vitamin D status over time.

Cardiovascular disease Vitamin D helps regulate the renin-angiotensin-aldosterone system and thereby blood pressure, vascular cell growth, and inflammatory and fibrotic pathways [ ]. Vitamin D deficiency is associated with vascular dysfunction, arterial stiffening, left ventricular hypertrophy, and hyperlipidemia [ ]. For these reasons, vitamin D has been linked to heart health and risk of CVD. Observational studies support an association between higher serum 25 OH D levels and a lower risk of CVD incidence and mortality.

For example, a meta-analysis included 34 observational studies that followed , participants mean age greater than 50 years for 1. The results showed that baseline serum 25 OH D levels were inversely associated with total number of CVD events including myocardial infarction, ischemic heart disease, heart failure, and stroke and mortality risk [ ].

Another large observational study that followed , adults from Denmark for 0—7 years found that levels of 25 OH D that were low about Other meta-analyses of prospective studies have found associations between lower vitamin D status measured by serum 25 OH D levels or vitamin D intakes and an increased risk of ischemic stroke, ischemic heart disease, myocardial infarction, and early death [ , ].

In contrast to the observational studies, clinical trials have provided little support for the hypothesis that supplemental vitamin D reduces the risk of CVD or CVD mortality.

For example, a 3-year trial in New Zealand randomized 5, adults mean age Vitamin D supplementation had no effect on the incidence rate of myocardial infarction, angina, heart failure, arrhythmia, arteriosclerosis, stroke, venous thrombosis, or death from CVD. Similarly, the VITAL clinical trial described above found that vitamin D supplements did not significantly decrease rates of heart attacks, strokes, coronary revascularization, or deaths from cardiovascular causes [ 93 ].

What gives off vitamin d

High serum cholesterol levels and hypertension are two of the main risk factors for CVD. The data on supplemental vitamin D and chole.