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Rickets
Definition:
Rickets is a childhood disorder involving softening and weakening of the bones. It is primarily caused by lack of vitamin D, calcium, or phosphate. Alternative Names:
Osteomalacia in children; Vitamin D deficiency; Renal rickets
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Causes, incidence, and risk factors:
Vitamin D may be absorbed from food by the intestines or may be produced by the skin when the skin is exposed to sunlight. In its active form, vitamin D acts as a hormone to regulate calcium absorption from the intestine and to regulate levels of calcium and phosphate in the bones. Sunlight is important to skin production of vitamin D, and environmental conditions where sunlight exposure is limited may reduce this source of vitamin D. Lack of vitamin D production by the skin may occur if a person is confined indoors, or works indoors during the daylight hours, or lives in climates with little exposure to sunlight. Because vitamin D is a fat-soluble vitamin, conditions that reduce digestion or absorption of fats will decrease the ability of vitamin D to be absorbed from the intestines. When the body is deficient in vitamin D, it is unable to properly regulate calcium and phosphate levels. If the blood levels of these minerals become too low, other body hormones may stimulate release of calcium and phosphate from the bones to the bloodstream to elevate the blood levels. Rickets is a bone disease that affects children when these deficiencies occur. It causes progressive softening and weakening of the bones' structure. There is a loss of calcium and phosphate from the bones, which eventually causes destruction of the supportive matrix. Rickets is fairly rare in the US. It is most likely to occur during periods of rapid growth, when the body demands high levels of calcium and phosphate. Rickets may be seen in young children 6 to 24 months old and is uncommon in newborns. Page: 1 | 2 | Next >>
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