Vitamin D Health Vitamin D (cholecalciferol) is also known as a sunlight vitamin because it can be synthesized under the human skin when it is exposed to sunlight.
Vitamin D actually refers to a group of steroid molecules and is derived from a steroid. There are two forms of this vitamin that is vitamin D2 or ergocalciferol and vitamin D3 or cholecalciferol. Calcitriol is the active form of vitamin D and is synthesized in the kidneys either from vitamin D2 or D3.
Vitamin D is essential for the proper absorption of calcium from the diet. It also controls the rate at which the body excretes calcium from the body and controls the level of calcium in the blood. Vitamin D is also required for building strong bones and teeth.
Vitamin D and osteoporosis – Insufficient exposure to sunlight and low levels of vitamin D in the body are both associated with the risk of developing osteoporosis. Adequate amount of vitamin D is essential to prevent bone loss because calcium cannot be absorbed from the food or supplements without adequate intake of vitamin D. Vitamin D when taken along with calcium helps to maintain the bone density which is critical in women especially after menopause.
Vitamin D and autoimmune diseases – Risk for certain autoimmune diseases like multiple sclerosis, IDDM or insulin dependent diabetes mellitus, and rheumatoid arthritis can be decreased by maintaining sufficient levels of vitamin D in the body.
Vitamin D and cancer – The immunomodulatory abilities of vitamin D may also play an important role in its anti-cancer activity. Vitamin D not only helps regulate the T-cells but also enhances the activity of phagocytes, antibody-dependent cytotoxicity of macrophages and boosts the natural killer cell activity. Certain analogues of vitamin D show significant experimental activity against breast, renal, prostate and colorectal cancers.
Vitamin D and psoriasis – Vitamin D and its analogues are sometimes used in the treatment of psoriasis as they are stimulator's for epidermal cell differentiation and potent anti proliferative agents for keratinocytes. As vitamin D plays a role in skin cell growth and metabolism, it may be helpful in treating the flaking and itching associated with psoriasis.
Vitamin D and other bone disorders – Vitamin D may also have a protective effect against other preventable bone diseases like osteomalacia and rickets.
In older people an adequate level of vitamin D is essential to prevent fractures and maintain strong bones. People suffering from genetic disease that interfere with vitamin D metabolism, vitamin D supplements are used.
Sources of Vitamin D – Exposure to sunlight is an important source of vitamin D as vitamin D3 is synthesized from 7-dehydrocholesterol using ultraviolet radiation from sunlight via photochemical reactions in the skin. Besides this vitamin D2 is derived from plant and fungal sources and vitamin D3 is derived from animal sources. Other good sources of vitamin D include milk, egg yolk, fatty fish, fish and cod liver oil. |
