NOW® Vitamin D softgels supply this key vitamin in a highly-absorbable liquid softgel form. Vitamin D is normally obtained from the diet or produced by the skin from the ultraviolet energy of the sun. However, it is not abundant in food. As more people avoid sun exposure, Vitamin D supplementation becomes even more necessary to ensure that your body receives an adequate supply.

Vitamin D and osteoporosis: Adequate amounts of vitamin D is necessary for preventing bone loss. Low levels of vitamin D and insufficient sunlight exposure are associated with osteoporosis. The body cannot absorb calcium from food or supplements without an adequate intake of vitamin D. After menopause, women are particularly at risk for developing this condition. Vitamin D taken along with calcium plays a critical role in maintaining bone density. Vitamin D functions by increasing the uptake of calcium from the intestine through interaction with the parathyroid glands in controlling bone resorption and serum calcium levels. Vitamin D also increases reabsorption of phosphate by the kidney tubule, and may directly affect the osteoblast, the cell which forms bone.

Vitamin D and cancer: Vitamin D's immunomodulatory abilities may also play a role in its anti-cancer activity. Vitamin D demonstrats a dose-dependent inhibition of cell proliferation in a number of cancer cell lines. It also has a pro-differentiation effect on these cells, resulting in potent anti-cancer activity in some preliminary work. vitamin D increases the potency of cytokines and enhances the phagocyte activity and antibody-dependent cytotoxicity of macrophages and that it boosts natural killer cell activity and helps regulate T cells, among other things. Vitamin D's analogues show significant experimental activity against colorectal, renal cell, breast and prostate cancers, among others.

Vitamin D and autoimmune diseases: Maintaining sufficient vitamin D levels may help decrease the risk of several autoimmune diseases such as insulin-dependent diabetes mellitus, multiple sclerosis, and rheumatoid arthritis. A daily multi-vitamin supplement containing vitamin D may reduce the risk of developing multiple sclerosis. Low intakes of vitamin D may be linked to an increased risk of arthritis of the hip in older women. One recent study showed that taking 400 IU or more of vitamin D daily was effective in delaying or stopping the progression of osteoarthritis of the knees. Autoimmune responses are mediated by immune cells called T cells. The biologically active form of vitamin D can modulate T cell responses, such that the autoimmune responses are diminished.

Vitamin D and psoriasis: Vitamin D is sometimesused in the treatment for psoriasis. Because vitamin D and its analogues are potent antiproliferative agents for keratinocytes and stimulators of epidermal cell differentiation. Calcipotriol has been demonstrated to significantly improve psoriatic lesions in a number of double-blind, placebo-controlled trials. Because it plays a role in skin cell metabolism and growth, vitamin D may be helpful in treating the itching and flaking associated with this skin ailment.

Vitamin D and other bone disorders: Vitamin D protects against the preventable bone diseases rickets and osteomalacia (softening of the bones in adults caused by inability to properly deposit calcium). An adequate level of Vitamin D in the body is necessary to maintain strong bones and to help prevent fractures in older people. Vitamin D supplements are also used for people with genetic diseases that interfere with the metabolism of Vitamin D.

Facts: Vitamin D actually refers to a group of steroid molecules. Vitamin D (calciferol) is named according to the revised rules of the International Union of Pure and Applied Chemists (IUPAC). Because vitamin D is derived from a steroid, the structure retains its numbering from the parent compound cholesterol. There are two forms of the vitamin. Vitamin D2 (ergocalciferol) is derived from ergosterol in the diet, whereas vitamin D3 (cholecalciferol) is derived from cholesterol via 7-dehydrocholesterol. Vitamin D3 (cholecalciferol) is found in animal skin, and vitamin D2 (ergocalciferol) is found in yeast. Cholecalciferol is generated in the skin of animals when light energy is absorbed by a precursor molecule 7-dehydrocholesterol. Plants synthesize ergocalciferol, which also has vitamin D activity in humans.

Vitamin D is called the sunlight vitamin because the body produces it when the sun's ultraviolet B (UVB) rays strike the skin. It is the only vitamin the body manufactures naturally and is technically considered a hormone. Vitamin D is important for the proper absorption of calcium from food. It is vital for the control of the levels of calcium in the blood and also controls the rate at which the body excretes calcium in the urine. The active form of the vitamin is calcitriol which is synthesized from either D2 or D3 in the kidneys. Calcitriol binds to a protein transcription factor which then regulates gene expression. Essential for building strong bones and teeth, vitamin D also helps to strengthen the immune system and may prevent some types of cancer.

Directions: As a dietary supplement, take one softgel daily with a meal.