Nutritional rickets revisited in children of Albanian origin (two cases)

Abstract

Listen

Translate article

Two cases of nutritional rickets of different etiology are described. Both were girls of Albanian origin. The first was a 10-month old girl born at full term who was presented with convulsions. Laboratory investigations revealed hypocalcemia (Ca 1.68 mmol/L), hypophosphatemia (Pi 0.52 mmol/L), high total alkaline phosphatase (ALP 579 IU/L) and rachitic lesions on the wrist and knees. Serum 25-hydroxy vitamin D (25OHD) and 1,25-dixydroxy vitamin D (1,25(OH)2D) were very low (1.0 nmol/L and 9.0 pmol/L respectively) and intact parathyroid hormone (iPTH) high (25.2 pmol/L). Urinary calcium excretion as expressed by the ratio of calcium/creatinine in a 2hr fasting urine sample (UCa/UCr) was high (1.52 mM/mM) while the renal tubular reabsorption of phosphate expressed by the ratio of maximum Pi reabsorption in the kidney in relation to glomerular filtration rate (TmP/GFR 0.5 mmol/L GF) was low. The baby had been exclusively breast fed to a vitamin deficient mother who had serum 25OHD 9.0 nmol/L in April and serum Ca 1.9 mmol/L. Her exposure to the sun was also scarce. After stopping the breast feeding and putting her on to a fortified milk formula as well as on a mixed food diet the girl had all biochemical markers normalized within three months. The other case was of a four-year old girl who had skin pallor, body weight<3rd centile, length<10th centile and clinical and radiological signs of rickets. She had low serum levels of phosphate (Pi 0.55 mmol/L), high ALP (742 IU/L) and iron deficient anemia. Her serum calcium was normal (SeCa 2.28 mmol/L) and so were her serum vitamin D metabolites (25OHD 47 nmol/L, 1,25(OH) 2D 49 pmol/L) and the serum iPTH (3.1 pmol/L). At first she was thought to have hypophosphatemic rickets, but after a short treatment with calcitriol and phosphate her serum Pi normalized (1.39 mmol/L). Hence the original diagnosis was reconsidered and after re-questioning about the child's diet, it was revealed that she did not eat meat, although she was drinking some milk and eating small quantities of dairy products leading to suspicion of nutritional rickets. After that, previous treatment stopped and meat was introduced in the diet for 4-6 times per week. The follow up of the child for the next eight months showed full normalization of her biochemical markers and healing of the rachitic lesions as verified by X-rays of the knees, justifying the final diagnosis of nutritional rickets.