Clinical Case 5.5

An 18-month-old child first walked at 14 months of age. She was noted to have an odd gait and deformity of the legs. Dietary vitamin D deficiency rickets was diagnosed at another hospital and she was treated with vitamin D2. By the age of 2 years her deformity was more marked (Box 5.31). She was reinvestigated. When taking her vitamin D2, her serum calcium was 2.32 mmol/l (NR 2.2–2.6 mmol/l) with a phosphate of 0.58 mmol/l (NR 1.16–1.91 mmol/l). The serum PTH concentration was 12 pmol/l (NR 1–6 pmol/l).

The child was diagnosed as having dietary vitamin D deficiency but the clinical features deteriorated while taking apparently adequate treatment; either the family had not been administering the treatment or the diagnosis was incorrect (or both). Family frictions made it difficult to obtain a full family history but, after lengthy discussions, the child's mother later admitted to having been treated for rickets in childhood and blamed her own mother for her childhood difficulties associated with this disease.