Osteomalacia

Definition

Osteomalacia is softening of the bones, caused by not having enough vitamin D, or by problems with the metabolism (breakdown and use) of this vitamin. These softer bones have a normal amount of collagen that gives the bones its structure, but they are lacking in calcium.

Causes

There are numerous causes of osteomalacia. In children, the condition is called rickets and is usually caused by a deficiency of vitamin D.

Conditions that may lead to osteomalacia include:

• Not enough vitamin D in the diet
• Not enough exposure to sunlight, which produces vitamin D in the body
• Malabsorption of vitamin D by the intestines

Other conditions that may cause osteomalacia include:

• Hereditary or acquired disorders of vitamin D metabolism
• Kidney failure and acidosis
• Phosphate depletion associated with not enough phosphates in the diet
• Cancer
• Side effects of medications used to treat seizures
• Liver disease

Use of very strong sunscreen, limited exposure of the body to sunlight, short days of sunlight, and smog are factors that reduce formation of vitamin D in the body.

Risk factors for osteomalacia are related to the causes. In the elderly, there is an increased risk among people who tend to remain indoors and those who avoid milk because of lactose intolerance.