Osteomalacia is the softening of the bones in adults due to defective bone mineralization.
The causes of adult osteomalacia are varied, but ultimately result in a vitamin D deficiency:
* Insufficient sunlight exposure, especially in dark-skinned subjects
* Insufficient nutritional quantities or faulty metabolism of vitamin D or phosphorus
* Renal tubular acidosis
* Malnutrition during pregnancy
* Malabsorption syndrome
* Chronic renal failure
* Tumor-induced osteomalacia
* Long-term anticonvulsant therapy
* Coeliac disease
Osteomalacia in adults starts insidiously as aches and pains in the lumbar region and thighs, spreading later to the arms and ribs. The pain is symmetrical, non-radiating and is accompanied by sensitivity in the involved bones. Proximal muscles are weak, and there is difficulty in climbing up stairs and getting up from a squatting position.Due to demineralization bones become less rigid. Physical signs include deformities like triradiate pelvis and lordosis. The patient has a typical "waddling" gait. Pathologic fractures due to weight bearing may develop.
Nutritional osteomalacia responds well to administration of 10,000 IU weekly of vitamin D for four to six weeks. Osteomalacia due to malabsorption may require treatment by injection or daily oral dosing of significant amounts of vitamin D.