- Is the impaired mineralization (deposition of hydroxyapatite) of bone in the mature skeleton. Due to inadequate phosphate and or calcium in the extracellular fluid, or a circulating inhibitor of mineralization
- Vitamin D deficiency.
- Abnormal vitamin D metabolism – liver/renal disease or drugs such as anticonvulsants, hypophosphatemia.
- Inhibitors of mineralization: aluminium, bisphosphanates, fluoride.
P/c: pain and deformity of long bones and pelvis (myopathy).
Ix: elevated alk. phos. reduced 25 hydroxyvitamin D, low urinary calcium, high urinary phosphate.
Tx: Vitamin D replacement