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I first became interested in vitamin D when I learned that it is not a vitamin. Instead, it is the only known substrate of a seco-steroid neuro-hormone that functions, like all steroids, by turning genes on and off.
That means it has as many different mechanisms of action as the genes it regulates. Moreover, vitamin D directly regulates hundreds, if not thousands, of the 21,000 coding genes of the human genome. Genes are responsible for making the proteins and enzymes the human body relies on for normal development and function.
Evidence that vitamin D is involved in the autism epidemic is mounting.
Prevent the most common type of cancer by simply knowing its causes and signs
Each year more new cases of skin cancer are diagnosed than the combined incidence of cancers of the breast, prostate, lung and colon, according to the Skin Cancer Foundation. The occurrence continues to rise. One in five Americans will develop skin cancer in the course of a lifetime.
This may be due to common misconceptions that sunscreen lotions provide adequate protection and that tanning booths are harmless. Brazil and Australia have banned indoor tanning altogether, and many more don't allow it for people under 18.
But melanoma, the deadliest type of skin cancer, is also the least common, Dr. Elizabeth Hale, senior vice president of the Foundation and board-certified dermatologist, says. All types are easily treatable if caught in advance. “Men have the highest mortality rate because they don’t get their skin checked often enough,” she adds.
Also, while 90 percent of non-melanoma skin cancers are associated with exposure to ultraviolet radiation from the sun, studies have shown that benign lesions have been the cause of a large increase in reported incidence of the disease.
Vitamin D is a precursor of the steroid hormone calcitriol that is crucial for bone and mineral metabolism. Both the high prevalence of vitamin D deficiency in the general population and the identification of the vitamin D receptor in the heart and blood vessels raised interest in the potential cardiovascular effects of vitamin D. Experimental studies have demonstrated various cardiovascular protective actions of vitamin D, but vitamin D intoxication in animals is known to induce vascular calcification. In meta-analyses of epidemiological studies, vitamin D deficiency is associated with an increased cardiovascular risk. Findings from Mendelian randomization studies and randomized, controlled trials (RCTs) do not indicate significant effects of a general vitamin D supplementation on cardiovascular outcomes. Previous RCTs, however, were not adequately designed to address extra skeletal events, and did not focus on vitamin D-deficient individuals. Therefore, currently available evidence does not support cardiovascular benefits or harms of vitamin D supplementation with the commonly used doses, and whether vitamin D has cardiovascular effects in individuals with overt vitamin D deficiency remains to be evaluated. Here, we provide an update on clinical studies on vitamin D and cardiovascular risk, discuss ongoing vitamin D research, and consider the management of vitamin D deficiency from a cardiovascular health perspective.
Key points
The vitamin D receptor (VDR) and enzymes for vitamin D metabolism are expressed throughout the cardiovascular system
VDR and 1α-hydroxylase knockout mice have hypertension with myocardial hypertrophy and increased activity of the renin–angiotensin–aldosterone system
The molecular effects of VDR activation indicate various anti-atherosclerotic and protective effects on the heart and on common cardiovascular risk factors
Observational studies have shown that low 25-hydroxyvitamin D levels are associated with an adverse cardiovascular risk profile and significantly increased risk of cardiovascular events
Mendelian randomization studies and randomized clinical trials have not shown significant effects of vitamin D on cardiovascular events, but these trials were not designed to investigate cardiovascular outcomes in vitamin D-deficient individuals
Vitamin D supplementation is currently not indicated for the purpose of cardiovascular disease prevention, but treatment of vitamin D deficiency is critical for skeletal health
Introduction
The critical involvement of vitamin D in bone and mineral metabolism is historically known. The identification of the vitamin D receptor (VDR) in almost all human organs including the heart and the blood vessels, and observations that individuals deficient in vitamin D are at increased risk of various extraskeletal diseases, stimulated research on the role of vitamin D for overall and cardiovascular health. In this Review, we summarize the existing knowledge on the effects of vitamin D on cardiovascular diseases and associated risk factors, with a particular focus on meta-analyses of large, epidemiological studies and randomized, controlled trials (RCTs). First, we provide a short summary of vitamin D metabolism and current vitamin D guidelines, a historical perspective on vitamin D and cardiovascular diseases, and a brief overview on the mechanistic effects of VDR activation on cardiovascular risk factors, the blood vessels, and the heart. The principal aspect of this Review is an update on observational studies, Mendelian randomization studies, and RCTs on vitamin D and cardiovascular risk. Finally, we outline and discuss ongoing vitamin D research, including large RCTs, and present our conclusions on how to deal with the management of vitamin D deficiency from a public health and cardiovascular health perspective.
