Vitamin D is a group of fat-soluble secosteroids responsible for enhancing intestinal absorption of calcium and phosphate. In humans, the most important compounds in this group are vitamin D3 (also known as cholecalciferol) and vitamin D2 (ergocalciferol). Cholecalciferol and ergocalciferol can be ingested from the diet and from supplements. The body can also synthesize vitamin D (specifically cholecalciferol) in the skin, from cholesterol, when sun exposure is adequate (hence its nickname, the “sunshine vitamin”).
Although vitamin D is commonly called a vitamin, it is not actually an essential dietary vitamin in the strict sense, as it can be synthesized in adequate amounts by most mammals exposed to sunlight. A substance is only classified as an essential vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from its diet. In common with other compounds commonly called vitamins, vitamin D was nevertheless discovered in an effort to find the dietary substance lacking in a disease, namely rickets, the childhood form of osteomalacia.Additionally, like other compounds called vitamins, in the developed world, vitamin D is added to staple foods, such as milk, to avoid disease due to deficiency.
Synthesis from exposure to sunlight, as well as intake from the diet, generally contribute to the maintenance of adequate serum concentrations. Evidence indicates the synthesis of vitamin D from sun exposure is regulated by a negative feedback loop that prevents toxicity, but, because of uncertainty about the cancer risk from sunlight, no recommendations are issued by the Institute of Medicine, USA, for the amount of sun exposure required to meet vitamin D requirements. Accordingly, the Dietary Reference Intake for vitamin D assumes no synthesis occurs and all of a person’s vitamin D is from food intake, although that will rarely occur in practice. Beyond its use to prevent osteomalacia or rickets, the evidence for other health effects of vitamin D supplementation in the general population is inconsistent. The best evidence of benefit is for bone health and a decrease in mortality in elderly women.
In the liver, cholecalciferol (vitamin D3) is converted to calcidiol, which is also known as calcifediol (INN), 25-hydroxycholecalciferol, or 25-hydroxyvitamin D3 — abbreviated 25(OH)D3. Ergocalciferol (vitamin D2) is converted in the liver to 25-hydroxyergocalciferol, also known as 25-hydroxyvitamin D2 — abbreviated 25(OH)D2. These are the two specific vitamin D metabolites that are measured in serum to determine a person’s vitamin D status. Part of the calcidiol is converted by the kidneys to calcitriol, the biologically active form of vitamin D. Calcitriol circulates as a hormone in the blood, regulating the concentration of calcium and phosphate in the bloodstream and promoting the healthy growth and remodeling of bone. Calcitriol also affects neuromuscular and immune function.
To learn more about this article go to: http://en.wikipedia.org/wiki/Vitamin_D
GLA Complex 60 ct.
GLA, Vitamin E, and Sunflower Seed Oil
GLA is used by many women to maintain a sense of well-being throughout their monthly cycle. This Shaklee formula contains GLA (gamma linolenic acid), an omega-6 fatty acid that our bodies use to form prostaglandins—potent, hormone-like substances that help the body to regulate many normal bodily processes.*
Come check out my website to learn more about GLA Complex.