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Deficiency of vitamin D can over a period of months cause rickets in children and osteomalacia in adults - a skeletal demineralization especially in the spine, pelvis, and lower extremities. Signs and symptoms of osteomalacia are burning in the mouth and throat, nervousness, diarrhea, and insomnia.
Vitamin D is a fat-soluble vitamin and while some is supplied by the diet, most of it is made in the body. To make vitamin D, cholesterol is necessary. Once cholesterol is available in the body, a slight alteration in the cholesterol molecule occurs, with one change taking place in the skin. This alteration requires ultraviolet light (sunlight). Vitamin D deficiency, as well as rickets and osteomalacia, tends to occur in persons who do not get enough sunlight and who fail to eat foods that are rich in vitamin D.
Once consumed or made within the body, vitamin D is further altered to produce a hormone called 1,25-dihydroxy-vitamin D (1,25-diOH-D). The conversion of vitamin D to 1,25-diOH-D does not occur in the skin, but in the liver and kidneys. First, vitamin D is converted to 25-OH-D in the liver; it then enters the bloodstream, where it is taken-up by the kidneys. At this point, it is converted to 1,25-diOH-D. Therefore, the manufacture of 1,25-diOH-D requires the participation of various organs of the body - the liver, kidneys, and skin.
The purpose of 1,25-diOH-D in the body is to keep the concentration of calcium at a constant level in the bloodstream. The maintenance of calcium at a constant level is absolutely required for human life to exist, since dissolved calcium is required for nerves and muscles to work. One of the ways in which 1,25-diOH-D accomplishes this mission is by stimulating the absorption of dietary calcium by the intestines.
Causes & Development; Risk Factors
Vitamin D deficiency can be caused by conditions that result in little exposure to sunlight. These conditions include: living in northern countries; having dark skin; being elderly or an infant, and having little chance to go outside; and covering one's face and body, such as for religious reasons. It is thus possible to acquire vitamin D deficiency, even if you live in a sunny climate.
Most foods contain little or no vitamin D. As a result, sunshine is often a deciding factor in whether vitamin D deficiency occurs. Although fortified milk and fortified infant formula contain high levels of vitamin D, human breast milk is rather low in the vitamin.
Rickets continues to be a problem in Africans and Asian Indians who migrate to Canada or Great Britain, especially where these immigrants do not consume fortified products.
Signs & Symptoms
No harm is likely to result from vitamin D deficiency that occurs for only a few days a year. If the deficiency occurs for a period of many months or years, however, rickets or osteomalacia may develop. The symptoms of rickets include bowed legs and bowed arms. The bowed appearance is due to the softening of bones, and their bending if the bones are weight-bearing.
Bone growth occurs through the creation of new cartilage, a soft substance at the ends of bones. When the mineral calcium phosphate is deposited onto the cartilage, a hard structure is created. In vitamin D deficiency, though, calcium is not available to create hardened bone, and the result is soft bone. Other symptoms of rickets include particular bony bumps on the ribs called rachitic rosary (beadlike prominences at the junction of the ribs with their cartilages) and knock-knees. Seizures may also occasionally occur in a child with rickets, because of reduced levels of dissolved calcium in the bloodstream.
Although osteomalacia is rare in the United States, symptoms of this disease include reduced bone strength, an increase in bone fractures, and sometimes bone pain, muscle weakness, and a waddling walk.
Diagnosis & Tests
A vitamin D deficiency diagnosis is confirmed by measuring the level of serum 25-hydroxy-vitamin D. The normal level or concentration of this form of the vitamin ranges from 25-50ng/ml. Deficiency occurs when this level decreases to about 12ng/ml or less. As mentioned previously, 25-OH-D is not the active form of the vitamin. It must be converted to 1,25-diOH-D in order to cause responses in various organs of the body. However, the levels of vitamin D, or of 1,25-dihydroxy-vitamin D in the blood, do not give a reliable picture of whether a person is deficient in the vitamin. For this reason, they are not measured when testing for vitamin D deficiency.
Rickets is diagnosed by X-ray examination of leg bones. A distinct pattern of irregularities, abnormalities, and a coarse appearance can be clearly seen with rickets. Osteomalacia is also diagnosed through X-ray examination. Measurements of blood plasma 25-OH-D, blood plasma calcium, and blood plasma parathyroid hormone must also be obtained for the diagnosis of these diseases. Parathyroid hormone and 1,25-diOH-D work together in the body to regulate the levels of calcium in the blood.
Treatment & Prevention
Rickets and osteomalacia are almost always treated with oral supplements of vitamin D, with the recommendation to acquire daily exposure to direct sunlight. An alternative to sunlight is the use of an ultraviolet (UV) lamp. When using UV lamps, the eyes must be covered to protect them against damage. Many types of sunglasses allow UV light to pass through, so only those that are opaque to UV light should be used. Attempts to acquire sunlight through glass windows fail to help the body make vitamin D. This is because UV light does not pass through window glass.
Rickets may also occur with calcium deficiency, even when a child is regularly exposed to sunshine. This type of rickets has been found in various parts of Africa. The bone deformities are similar to, or are the same as, those that occur in typical rickets; however, calcium deficiency rickets is treated by increasing the amount of calcium in the diet. No amount of vitamin D can cure the rickets of a child with a diet that is extremely low in calcium. For this reason, it is recommended that calcium be given in conjunction with vitamin D supplementation.
Food fortification has almost completely eliminated rickets in the United States. Vitamin D deficiency can be prevented by acquiring the RDA through consuming fortified products or taking supplements in the form of pills. In some older people, a 400 IU supplement may not be enough to result in the normal absorption of calcium; therefore, daily doses of 10,000 IU per day may be needed. For infants who are fed only breast milk (and rarely exposed to sunshine), a daily supplement of 200-300 IU is recommended.
Prognosis; Complications
The prognoses for correcting vitamin D deficiency, rickets, and osteomalacia are excellent. Vitamin D treatment results in the return of bone mineralization to a normal rate, the correction of low plasma calcium levels, the prevention of seizures, and a recovery from bone pain. On the other hand, deformities such as bowed legs and the rachitic rosary generally persist throughout adult life.
The sequence of events that can lead to vitamin D deficiency, and then bone disease, is as follows: a lack of vitamin D in the body creates an inability to manufacture 1,25-diOH-D, which results in decreased absorption of dietary calcium and increased loss of calcium in the feces. When this happens, the bones are affected. Vitamin D deficiency results in a lack of bone mineralization (calcification) in growing persons, or in an increased demineralization (decalcification) of bone in adults.
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Signs, symptoms & indicators of Vitamin D Requirement:
Risk factors for Vitamin D Requirement: | | | | | Childhood |  Sweaty head as a child
Sensitive hair during childhood
Easily-tired legs as a child | This is symptomatic of a childhood vitamin D deficiency which may in turn indicate a vitamin D dependency throughout a person's life. A dependency is a greater than average requirement, requiring greater intake and/or sun exposure. If there is no indication of vitamin D deficiency as an adult then that is the end of the matter. |
Childhood rocking or head-rolling
Growing pains in childhood |
Personal Background |
 Living at 41°-56°/living at over 56°/living at 24°-40° latitude| | The body's main source of vitamin D is sunlight, but higher latitudes mean less available sunlight - especially during the winter. At most latitudes in the United States, little or no vitamin D is made in the skin in the late fall (autumn) and early winter. In the most northern regions, the vitamin D blackout lasts for about six months. As a result, it has been estimated that up to 70% of Americans (and Europeans) may be deficient in vitamin D. Only in the last several hundred years has urbanization, industrialization, glass (UVB does not penetrate glass), excessive clothes (UVB does not penetrate clothes) and sunblock greatly lowered levels. |
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Supplements and Medications |
Counter-indicators:
 Much/some vitamin D supplementation| | Even if one is taking vitamin D supplements, vitamin D recommendations keep going up. It is difficult to take, for example, 1,000 IU, which may be what is needed. Ideally, sunlight exposure should be one's source. |
 Multiple vitamin use |
Symptoms - Environment |
Low recent sun exposure
Counter-indicators:
High recent sun exposure |
Symptoms - Food - Preferences |
(Partial) vegetarian diet or raw food/vegan diet |
Symptoms - Gas-Int - General |
Having had a small bowel resection |
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Vitamin D Requirement can lead to: | | | | | Circulation | Hypertension| | An Alabama researcher found that lack of enough sunshine exposure may increase risk of hypertension in blacks and other dark-skinned people. Those with greater amounts of pigment in the skin require six times the amount of ultraviolet B (UVB) light to produce the same amount of vitamin D3 found in lighter-skinned people. |
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Vitamin D Requirement could instead be:
Recommendations and treatments for Vitamin D Requirement: | | | | | Vitamins |  Vitamin D| | Rickets heals promptly with 4,000 IU of oral vitamin D per day administered for approximately one month. During this treatment, the doctor should monitor the levels of 25-OH-D in the plasma to make certain they are raised to a normal value. The bone abnormalities (visible by X-ray) generally disappear gradually over a period of 3-9 months. Parents are instructed to take their infants outdoors for approximately 20 minutes per day with their faces exposed. Children should also be encouraged to play outside.
Osteomalacia is treated by eating 2,500 IU per day of vitamin D for about three months. Measurements of 25-OH-D, calcium, and parathyroid hormone should be obtained after the treatment period to make sure the therapy did, in fact, result in normal blood values. |
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Preventive measures against Vitamin D Requirement: | | | | | Environmental | Sunlight Exposure| | People should aim to get 10 to 15 minutes of exposure to direct sunlight each day when the weather allows, without sunscreen, to allow adequate synthesis of vitamin D. Most people achieve this simply by going about their daily activities. Those living at higher latitudes (further from the equator) should supplement their diets to ensure they are getting enough vitamin D, particularly during winter. A lack of sun during the winter months means that many people are deficient in this vitamin by December each year.
In the spring and summer, light-skinned adults can make large amounts (20,000 IU) by sunbathing on both sides, without sunblock, for a few minutes (about one-third the time it takes for the skin to begin to slightly redden). Darker-skinned persons need five to 10 times longer depending on the amount of melanin pigment in the skin.
Vitamin D production occurs within minutes and is maximized long before the skin turns red or begins to tan. One does not have to get repeated blood tests when using sun exposure to obtain vitamin D. Toxicity can not occur even with heavy and continuous sunbathing because ultraviolet light begins to degrade vitamin D after making about 20,000 IU, thus reaching a steady state. |
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KEY | | Weak or unproven link | | | Strong or generally accepted link | | | Strongly counter-indicative | | | Very strongly or absolutely counter-indicative | | | Highly recommended |
GLOSSARY
Calcium
The body's most abundant mineral. Its primary function is to help build and maintain bones and teeth. The body also needs calcium to carry nerve signals, keep the heart functioning, contract muscles, clot blood and maintain healthy skin. Calcium helps control blood acid-alkaline balance, plays a role in cell division, muscle growth and iron utilization, activates certain enzymes, and helps transport nutrients through cell membranes. Calcium also forms a cellular cement called ground substance that helps hold cells and tissues together.
Cartilage
Specialized fibrous connective tissue that forms the skeleton of an embryo and much of the skeleton in an infant. As the child grows, the cartilage becomes bone. In adults, cartilage is present in and around joints and makes up the primary skeletal structure in some parts of the body, such as the ears and the tip of the nose.
Cholesterol
A waxy, fat-like substance manufactured in the liver and found in all tissues, it facilitates the transport and absorption of fatty acids. In foods, only animal products contain cholesterol. An excess of cholesterol in the bloodstream can contribute to the development of atherosclerosis.
Crohn's Disease (Crohn's)
Chronic inflammatory disease of the gastrointestinal tract. The most common symptoms are abdominal pain, often in the lower right area, and diarrhea. Rectal bleeding, weight loss, and fever may also occur. Bleeding may be serious and persistent, leading to anemia.
Diarrhea
Excessive discharge of contents of bowel.
Distal
Anatomically located further away from a point of reference, such as an origin or a point of attachment.
Fibromyalgia (FMS)
Originally named fibrositis, it is a mysteriously debilitating syndrome that attacks women more often than men. It is not physically damaging to the body in any way, but is characterized by the constant presence of widespread pain that often moves about the body. Fibromyalgia can be so severe that it is often incapacitating.
Hormones (Hormone)
Chemical substances secreted by a variety of body organs that are carried by the bloodstream and usually influence cells some distance from the source of production. Hormones signal certain enzymes to perform their functions and, in this way, regulate such body functions as blood sugar levels, insulin levels, the menstrual cycle, and growth. These can be prescription, over-the-counter, synthetic or natural agents. Examples include adrenal hormones such as corticosteroids and aldosterone; glucagon, growth hormone, insulin, testosterone, estrogens, progestins, progesterone, DHEA, melatonin, and thyroid hormones such as thyroxine and calcitonin.
Hypertension
High blood pressure. Hypertension increases the risk of heart attack, stroke, and kidney failure because it adds to the workload of the heart, causing it to enlarge and, over time, to weaken; in addition, it may damage the walls of the arteries.
IU (mIU, uIU)
International Unit: An arbitrarily defined but agreed upon unit that depends on what is being measured.
mIU: 0.001 or one thousandth of an IU.
uIU: 0.000001 or one millionth of an IU.
Kidneys (Kidney, Renal)
Bean-shaped organs, each about the size of a fist. They are located near the middle of the back, just below the rib cage. The kidneys are sophisticated reprocessing machines, each day handling about 50 gallons of blood to sift out about half a gallon of waste products and extra water. The waste and extra water become urine, which flows to the bladder through tubes called ureters. The actual filtering occurs in tiny units inside the kidneys called nephrons. Every kidney has about a million nephrons. In a nephron, a glomerulus -- which is a tiny blood vessel, or capillary -- intertwines with a tiny urine-collecting tube called a tubule. A complicated chemical exchange takes place, as waste materials and water leave your blood and enter your urinary system. The kidneys recycle chemicals such as sodium, phosphorus, and potassium and thus regulate their levels. Renal: Pertaining to the kidneys.
Liver (Hepatic)
The largest and one of the most complex organs of the body, the liver is responsible for much of the metabolism of fats, proteins and carbohydrates. It is the site of much of the body's detoxification. It is connected very closely with digestion and the regulation of blood sugar, among many other functions. Found behind the ribs on the right side of the abdomen, it has many important functions such as removing harmful material from the blood, making enzymes and bile that help digest food, and converting food into substances needed for life and growth. Hepatic: Pertaining to the liver.
Malabsorption
Improper utilization of needed and available nutrients, either from impaired digestive function (such as B12 being unabsorbed because of gastritis), impaired absorption (poor Vitamin E absorption because of an inflamed ileum) or impaired transport (the diminished blood proteins of the advanced alcoholic). There are other causes as well.
Melanin
A dark pigment produced in the skin. Dark-skinned individuals produce more melanin, and melanin production increases in response to sunlight, causing the skin to become darker.
Milliliter (mL)
0.001 or one thousandth of a liter.
Mineral (Minerals)
Plays a vital role in regulating many body functions. They act as catalysts in nerve response, muscle contraction and the metabolism of nutrients in foods. They regulate electrolyte balance and hormonal production, and they strengthen skeletal structures.
Nanogram (ng)
0.000000001 or a billionth of a gram.
Parathyroid Hormone
A hormone released by the parathyroid glands that acts to keep a constant level of calcium in body tissues.
Pelvis
The lower part of the abdomen between the hip bones. Organs in a woman's pelvis include the uterus, vagina, ovaries, fallopian tubes, bladder and rectum.
RDA (RDAs, US RDA, USRDA)
Recommended Daily Allowance of vitamins or other nutrients as determined by the FDA. U.S. RDAs are more widely used than RDAs, and focus on 3 age groups: Infants of 0-12 months; Children of 1-4 years; Adults and children of more than 4 years.
Rickets
Vitamin-D deficiency characterized by abnormal calcification of bone tissues.
Seizure (Seizures)
While there are over 40 types of seizure, most are classed as either partial seizures which occur when the excessive electrical activity in the brain is limited to one area or generalized seizures which occur when the excessive electrical activity in the brain encompasses the entire organ. Although there is a wide range of signs, they mainly include such things as falling to the ground; muscle stiffening; jerking and twitching; loss of consciousness; an empty stare; rapid chewing/blinking/breathing. Usually lasting from between a couple of seconds and several minutes, recovery may be immediate or take up to several days.
Serum
The cell-free fluid of the bloodstream. It appears in a test tube after the blood clots and is often used in expressions relating to the levels of certain compounds in the blood stream.
Small Intestine (Small Bowel)
The small intestine lies between the stomach and the large intestine. It is about 6 meters (20 feet) long and its primary function is to digest (break down) food and absorb nutrients (vitamins, minerals, proteins, carbohydrates, and fats). The small intestine makes up more than 70% of the length and 90% of the surface area of the gastrointestinal (GI) tract.
Vitamin D
A fat-soluble vitamin essential to one's health. Regulates the amount of calcium and phosphorus in the blood by improving their absorption and utilization. Necessary for normal growth and formation of bones and teeth. For Vitamin D only, 1mcg translates to 40 IU.
X-rays (X-ray)
High-energy radiation used to take pictures of areas inside the body.
Last updated: Apr 13, 2008
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