Vitamin D
In 1824, cod liver oil, long known as a folk medicine, was found to be important in the treatment of rickets, but soon it lost favor with physicians because they could not explain how it worked. Not much has changed since that time in the medical field when it comes to foods curing illnesses.
Vitamin D is a fat soluble vitamin, which means that it can be stored within the body for long periods of time. It is acquired through sunlight or diet. When the body is exposed to the sun, Vitamin D is considered to be both a vitamin and a prohormone because of its action with 7-dehydrocholesterol found underneath the skin. Ultraviolet sun rays act on the oils of the skin to produce the vitamin, which is then absorbed into the body. This vitamin goes on to be metabolized in the liver, and still further in the kidneys to an activated form. It then returns to the intestinal mucosal cells, where it begins the production of a calcium-binding protein needed for the absorption of calcium from the intestines. Factors that block sunlight will determine the effectiveness of obtaining Vitamin D from the sun.
Vitamin D is necessary for the growth of strong bones and teeth through the proper utilization of calcium and phosphorus. Deficiency of these nutrients, especially Vitamin D, produces rickets, mainly a childhood disorder manifested by bowed legs. It appears more often in parts of the world where the winters are especially long and where smoke, fog, or smog continually interfere with sunshine. In addition, dark skinned people (whether natural or induced) are more susceptible to this disease since skin pigment can block absorption of the sun's rays. Therefore, once a suntan is established, Vitamin D production through the skin no longer occurs.
Rickets is commonly thought of as being merely "bowed" legs or "knocked knees." However, it is much more than that. Not only do the weight-bearing bones buckle, but as growth takes place, the head becomes malformed, wrists and ankles become enlarged, and the sternum bows to resemble a pigeon breast. The severity of the changes varies with the degree of Vitamin D deficiency. Even early recognition often escapes trained health care professionals. Infants may be restless and sleep poorly. They may sweat profusely, something which is uncommon in infants, and repeatedly turn its head from side to side. Later, there will be a delay in the formation of teeth. The infant will have reduced mineralization of the skull or craniotabes, bossing of the skull, and delayed closure of the fontanelle. Sitting and crawling stages will be noticeably delayed. By the time the "bowed" legs appear, the child is well into the deficiency. Supplements of Vitamin D can correct bone structure development but they will not be able to correct deformed bones.
When a Vitamin D deficiency occurs in adults, it produces a condition known as "osteomalacia," a softening of the bone, sometimes referred to as the adult form of rickets. It occurs after the epiphyseal growth plates fuse, creating bone-softening deformities of arms, legs, spine, thorax, and pelvis. Compounding these problems are the accompanying chronic pain and muscle weakness. It is often confused with osteoporosis. However, with osteoporosis, bone fractures are common, but not so in osteomalacia. Studies in the US indicate that almost half of hip fracture victims have a Vitamin D deficiency.
Vitamin D deficiency can not only contribute to rickets and osteoporosis, but also to calcium loss in the bones of the inner ear. Hearing loss may be related to malformation of the middle ear bones or changes that occur to the bones related to a deficiency of Vitamin D, especially in the elderly. Because of the vitamin's effect on the eye muscles, a deficiency can also contribute to nearsightedness. Vitamin D has been used in the treatment of conjunctivitis.
Vitamin D belongs to a group of several related sterols, with the two most important ones being D2 and D3. D2 is derived from plants and can substitute for D3 in the human body. D3 is the natural form found in foods and made by the skin when exposed to sunlight. D3 is also the major circulating form of Vitamin D and is the form measured in assessing the Vitamin D status of patients. Since Vitamin D3 is considered a prohormone, it does not have any activity of its own. It is only after D3 is metabolized in the liver and then into other forms in the kidneys that the active forms are produced. To date, some thirty-seven forms of Vitamin D3 have been isolated and chemically characterized.
The majority of the biological responses that we attribute to Vitamin D occurs through its acting as a steroid hormone involved in calcium metabolism. The calcium balance is not only regulated by Vitamin D and the interaction of three hormones, but also by PTH (parathormone) and calcitonin. It is commercially available in a form especially for the treatment of hypocalcemia in patients with chronic renal failure undergoing dialysis.
Vitamin D has shown to inhibit tumor growth BOTH when taken internally and when applied topically. It has also shown to stimulated human macrophages to attack the bacterium that causes tuberculosis, slowing it down and eventually stopping its growth. Deficiencies in Vitamin D often coexist with such other deficiencies as Vitamin C which can mask or modify important symptoms of scurvy. RDA is 400 IU daily for adults and infants, providing the calcium intake is adequate and rarely is more needed. Vitamin D works best with ample supplies of Vitamins A, C, choline, calcium, and phosphorus.
Summary:
Names include: rachitamin, rachitasterol, antirachitic factor, and the "sunshine vitamin". On commercial labels, it may appear as "calciferol", "ergocalciferol", or "cholecalciferol."
Forms include: Vitamin D1/lamisterol; Vitamin D2/ergocalciferol/viosterol/activated ergosterol; Vitamin D3/cholecalciferol/ergosterol/activated 7-dehydrocholesterol; Vitamin D4/dihydrotachysterol/22:23-dihydrovitamin D2; vitamin D5/irridated 7-dehydrositosterol; Vitamin Dc; Vitamin Dm.
Deficiency symptoms include: rickets, bone demineralization, softening bones/teeth, decreased calcium absorption, weakness, decreased muscle tone, fatigue, cramps, constipation, emotional agitation, decreased serum cholesterol, decreased kidney function.
Toxicity symptoms include: (detoxified by Vitamin C), thirst, increased urination and urgency of urination, kidney failure, diarrhea, nausea, decreased appetite and weight, headaches, depression, increased susceptibility to sunstroke, calcium deposits in blood vessels/liver/lungs/kidneys/stomach/skin, depleted magnesium levels, weakness, constipation, aches, stiffness, abnormal bone growth in children, numbness/tingling in bones and fingertips, increased blood pressure.
There are no known toxicities associated with Vitamin D3, only in the other forms.
Inhibitors include: mineral oil, smog, laxatives, phenturide, promidone, pheytoin, phenobarbitone, the hypnotic glutethimide, corticosteroids, anticonvulsants.
Helpers include: Vitamins A, Bp, C, F, T, calcium, phosphorus.
Vitamin D1 is a specific form of Vitamin D and is also known as lamisterol and forms calciferol.
Vitamin D2 is the synthetic form of Vitamin D. Other names include: ergocalciferol, oleovitamin D2, viosterol, activated ergosterol, Calciferol, Drisdol, D-Tracetten, Divit Urto, Ostelin, Condol, Ergorone, Davitin, Metadee, Mina D2, Mulsiferol, Mykostin, Radsterin, Shock-Ferol, Dee-Ron, Decaps, Deltalin, De-Rat Concentrate, Deratol, Hi-Deratol, Detalup, Diactol, Doral, Vio-D, Ertron, Infron, Radiostol, Sterogyl, Fortodyl.
Vitamin D3 is the internal form of Vitamin D. Other names include: cholecalciferol, ergosterol, calcidiol, activated 7-dehydrocholesterol, 25-Hydroxycholecalciferol, 25-Hydroxyvitamin D3, oleo-Vitamin D3, CC, Calderol, Duphafral D31000, Delsterol, Deparal, Ebivit, Micro-Dee, NeoDohyfral D3, Provitina, Ricketon, Trivitan, D3-Vicotrat, Vi-De-3-hydrosol, Vigantol, Vigorsan.
Vitamin D4 is an ineffective form of Vitamin D. Other names include: oleovitamin D4, 22:23-dihydrovitamin D2, 22,23-dihydroergocalciferol. It forms dihydrotachysterol.
Vitamin D5 is a specific form of Vitamin D otherwise known as: irridated 7-dehydrositosterol.
Vitamin Dc is a specific form of Vitamin D.
Vitamin Dm is a specific form of Vitamin D.
