What causes osteomalacia?
Osteomalacia is a condition in which the bones become soft. It is caused by not getting enough vitamin D (vitamin D deficiency). A deficiency in vitamin D leads to the loss of calcium and phosphorus, both of which are necessary for making bones hard and strong. Osteomalacia is the adult version of rickets. A vitamin D deficiency leading to osteomalacia may be
caused by a poor diet (malnutrition) or by a problem with the intestines (such as sprue) that prevents them from absorbing nutrients.
Vitamin D is a fat-soluble vitamin, meaning it is able to be dissolved in fat. While some vitamin D is supplied by the diet, most of it is made in the body. To make vitamin D, cholesterol, a sterol that is widely distributed in animal tissues and occurs in the yolk of eggs, as well as in various oils and fats, 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 the energy of sunlight (or ultraviolet light). 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.
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. Many Arab women cover the entire body with black cloth, and wear a veil and black gloves when they go outside. These women may acquire vitamin D deficiency, even though they live in a sunny climate. |
