Bone softening caused by impaired mineralization.

Pathophysiology: Vitamin D deficiency and defective vitamin D metabolism- Hypocalcemia → defective bone matrix mineralization - Renal disease → ↓ production of vitamin D and metabolic acidosis → impaired calcification

Clinical features:- Occurs in adults - Bone pain and tenderness- Pathologic fractures- Waddling gait and difficulty walking- Myopathy: muscle weakness, spasms, and/or cramps- Symptoms of hypocalcemia

Diagnostics: - Lab: Calcium ↓, phosphate ↓, alkaline phosphatase ↑, parathyroid hormone ↑- X-ray: Low bone mineral density, thin cortices, looser zones (pseudofractures): transverse bands of radiolucency indicating defective calcification of osteoid

Treatment:- Administration of vitamin D- Adequate daily intake of calcium