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Hypercalciuria and bone disease are frequently associated with total parenteral nutrition (TPN) in children and adults. The aim of this study was to assess the influence of calcium, phosphorus, and vitamin D intakes on hypercalciuria. We observed seven children aged 4-13 years receiving home cyclic TPN for 4 consecutive years. Calcium and phosphorus intakes, constant during the 1st year, were reduced during the last 3 years to 50 and 30% of the initial intakes, and vitamin D was stopped during the 3rd and the 4th years. All children had hypercalciuria and one of them had acute painful osteopenia and nephrocalcinosis at the beginning of the study. Hypercalciuria was corrected and painful bone disease did not occur during the three following years, with TPN daily intakes of calcium, 0.35 mmol/kg, and phosphorus, 0.70 mmol/kg. Cessation of vitamin D administration during 48 months led to no further decrease in calciuria nor to the occurrence of clinical or biological signs of vitamin D deficiency. However, we hypothesize that excessive vitamin D intake may have facilitated the occurrence of the TPN-related bone disease in one patient and should be avoided. The possible role of parenteral aluminum loading is also discussed.

We report the beneficial effects of calcium infusions in a child with hereditary resistance to 1,25(OH)2D and alopecia. This patient after transient responsiveness to vitamin D derivatives became unresponsive to all therapy despite serum 1,25(OH)2D concentrations maintained at levels approximately 100-fold normal. A 7-mo trial with calcium infusions led to correction of biochemical abnormalities and healing of rickets. Bone biopsies (n = 3) showed a normal mineralization and the disappearance of the osteomalacia. Cultures of bone-derived cells demonstrated a lack of activation of 25-hydroxyvitamin D 24-hydroxylase and osteocalcin synthesis by 1,25(OH)2D3 (10(-9) and 10(-6) M). These results demonstrate that even in the absence of a normal 1,25(OH)2D3 receptor-effector system in bone cells, normal mineralization can be achieved in humans if adequate serum calcium and phosphorus concentrations are maintained; and calcium infusions may be an efficient alternative for the management of patients with this condition who are unresponsive to large doses of vitamin D derivatives.