D3 1000
Vitamin D is synthesized in the human body when the skin is exposed to sunlight, and differs from all other vitamins because its active form is actually a hormone, sending a signal to increase the intestinal absorption of calcium and phosphorus. There are 2 forms of vitamin D available in supplement form, vitamin D2 and vitamin D3. The most bioactive is vitamin D3, also known as cholecalciferol, which is derived from sheep lanolin (wool). There are very few food sources of vitamin D, and most North American dietary sources come from fortified foods. Vitamin D is produced endogenously when the skin is exposed to UVB rays from the sun. If you live north of the equator, you will only be able to produce vitamin D for 3 to 6 months a year.
The Functions of Vitamin D
The main function of vitamin D is the regulation of calcium levels. If calcium levels fall, production of active vitamin D will increase. This in turn enhances the absorption of calcium and slows renal excretion of the mineral. It is well known that vitamin D is essential for bone health, but it is also important for cell differentiation, especially for epithelial and white blood cells. Vitamin D also enhances the immune system and improves the activity of white blood cells. Furthermore, vitamin D is important for neurological function and may reduce the incidence of multiple sclerosis and schizophrenia.
Vitamin D deficiency
· Vitamin D deficiency is very common. In a study of 290 hospital patients, 57% were vitamin D deficient and 22% were severely deficient.
· Elders are more likely to be vitamin D deficient. Indeed, endogenous synthesis of vitamin D decreases with age, and production is less than half of that expected in younger counterparts.
· Sunscreens with a sun protection factor of 8 or more completely prevent vitamin D synthesis.
· Vitamin D is poorly absorbed by people affected by fat malabsorption, liver or biliary disease, Crohn's disease and cystis fibrosis.
· Risk of deficiency in strict vegetarians is high because vitamin D is only found in animal foods.
Research Summary
· Vitamin D is used to treat rickets. Taken with calcium it can reduce and prevent bone loss in osteoporotic patients.
· Vitamin D receptors are present in cells of the Immune System.
· Vitamin D is important for the biosynthesis of neutrophic factors and neurotransmitters.
· In a recent study, 1238 men and women had lower neuromuscular function if their vitamin D levels were suboptimal.
Vitamin D is not only important for bone health. Its role in cancer, immunity, seasonal depression, seizures, diabetes, infertility and multiple sclerosis is being examined. Studies on vitamin D suggest that supplementation is necessary for most, particularly those living in northern latitudes.
