Osteomalacia is the softening of the bones due to defective bone mineralization secondary to inadequate amounts of available phosphorus and calcium, or due to overactive resorption of calcium from the bone due to hyperparathyroidism (which causes hypercalcemia, in contrast to other etiologies). Osteomalacia in children is known as rickets, and because of this, use of the term osteomalacia is often restricted to the milder, adult form of the disease. It may show signs as diffuse body pains, muscle weakness, and fragility of the bones. The most common cause of the disease is a deficiency in vitamin D, which is normally obtained from the diet and/or sunlight exposure.
Osteomalacia in adults starts insidiously as aches and pains in the lumbar (lower back) 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. However, those physical signs may derive from a previous osteomalacial state, since bones do not regain their original shape after they become deformed.
Pathologic fractures due to weight bearing may develop. Most of the time, the only alleged symptom is chronic fatigue, while bone aches are not spontaneous but only revealed by pressure or shocks.
It differs from renal osteodystrophy, where the latter shows hyperphosphatemia