A growing body of research shows that adequate vitamin D intake is important for the regulation of calcium and phosphorus absorption, maintenance of healthy bones and teeth, according to an online article by Megan Ware, RDN. (The article, published in a recent issue of Medical News Today, was reviewed by Dr. Helen Webberley.)
In spite of the name, vitamin D is considered a pro-hormone and is not actually a vitamin. This is because the body is capable of producing vitamin D, while vitamins are nutrients that cannot be synthesized by the body and must be acquired through the diet or supplements.
Research shows that sensible sun exposure on bare skin for 5-10 minutes two or three times a week allows the body the ability to produce sufficient vitamin D. However, vitamin D has a half-life of only two weeks, meaning that stores can run low, especially in winter and in northern climates, according to research results. Recent studies suggest that up to 50 percent of adults and children worldwide are vitamin D deficient.
Vitamin D is produced when sunlight converts cholesterol on the skin into calciol (vitamin D3). Vitamin D3 is then converted into calcidiol (25-hydroxyvitamin D3) in the liver. The kidneys then convert calcidiol into the active form of vitamin D, called calcitriol (1,25-hydroxyvitamin D3). As such, statins and other medications or supplements that inhibit cholesterol synthesis, liver function or kidney function can impair the synthesis of vitamin D, according to the online article.
The human body needs vitamin D to absorb calcium in the intestines and to reclaim calcium that would otherwise be excreted through the kidneys.
Vitamin D supplementation can improve mood and provide long-term protection against cognitive decline and bone deterioration, according to an article at Examine.com, an independent supplement research service.
Taking vitamin D supplements can improve exercise performance and lower the risk of heart disease, according to findings in a preliminary study presented at the Society for Endocrinology annual conference in Edinburgh, Scotland. The study was reported in the January 2016 issue of Vitamin Retailer magazine.
Research is ongoing into the potential benefits sufficient vitamin D may have for the human body, with some studies showing possible protective effects for a number of physical conditions.