RESUMEN
In 10 patients with renal tubular acidosis, seven with type I and three with Fanconi syndrome, simultaneous measurements of vitamin D metabolites and electrolytes were made. No marked abnormalities of calcidiol2, calcidiol3, 24,25(OH)2D, or calcitriol were found in these patients, whose mean serum HCO3 was 18 +/- 3 mM/L (SD). Further, no relationship between serum HCO3 and calcitriol could be found. These results suggest that either vitamin D deficiency may be required before any alterations in the production of calcitriol are seen, or that the effects of acidosis in animals may not be reflected in humans. Further, it appears less likely that the bone disease found in renal tubular acidosis is related to abnormalities in vitamin D metabolism resulting from systemic acidosis, but that bone disease is more likely related to the acidosis and hypercalcuria prevalent in this disorder.
Asunto(s)
Acidosis Tubular Renal/sangre , Calcitriol/sangre , Animales , Bicarbonatos/sangre , Calcio/sangre , Calcio/orina , Pollos , Niño , Femenino , Humanos , Masculino , Fosfatos/sangre , Fosfatos/orina , Ratas , Vitamina D/sangreAsunto(s)
Cistinosis/tratamiento farmacológico , Enfermedades Renales/tratamiento farmacológico , Vitamina D/metabolismo , Calcifediol/sangre , Calcifediol/uso terapéutico , Calcitriol/sangre , Calcitriol/uso terapéutico , Niño , Cistinosis/sangre , Cistinosis/metabolismo , Dihidrotaquisterol/sangre , Dihidrotaquisterol/uso terapéutico , Ergocalciferoles/análogos & derivados , Ergocalciferoles/sangre , Ergocalciferoles/uso terapéutico , Humanos , Enfermedades Renales/sangre , Enfermedades Renales/metabolismo , Vitamina D/sangreAsunto(s)
Dihidroxicolecalciferoles/sangre , Sangre Fetal/análisis , Hidroxicolecalciferoles/sangre , 25-Hidroxivitamina D 2 , Calcitriol , Calcio/sangre , Dihidroxicolecalciferoles/biosíntesis , Femenino , Humanos , Hipocalcemia/sangre , Recién Nacido , Enfermedades del Prematuro/sangre , Magnesio/sangre , Intercambio Materno-Fetal , Hormona Paratiroidea/sangre , Fósforo/sangre , Embarazo , Población UrbanaRESUMEN
Osteodystrophy frequently accompanies severe childhood hepatobiliary disease. Proposed causes include malabsorption of vitamin D and calcium, and diminished 25-hydroxylation of vitamin D. Two children, ages 23 and 35 months, with radiographic and biochemical evidence of rickets with extrahepatic biliary atresia, were treated with 1,25-dihydroxyvitamin D3. The minimal effective therapeutic dose and efficacy of 1,25-(OH)2D3 in the treatment of rickets associated with severe childhood hepatic disease were determined. Oral 1,25-(OH)2D3 was ineffective at doses of 0.10 microgram/kg/day. Parenteral doses of 0.20 microgram/kg/day effectively produced radiographic, bone mineral (photon absorptiometric), and biochemical evidence of healing. The need for four times the physiologic dose of 1,25-(OH)2D3 by the parenteral route suggested enhanced catabolism of, or end-organ resistance to, 1,25-(OH)2D3 in our patients with severe cholestatic liver disease treated with phenobarbital.
Asunto(s)
Dihidroxicolecalciferoles/uso terapéutico , Hidroxicolecalciferoles/uso terapéutico , Hepatopatías/complicaciones , Raquitismo/tratamiento farmacológico , Conductos Biliares/anomalías , Femenino , Humanos , Lactante , Masculino , Raquitismo/etiologíaRESUMEN
Rickets with alopecia, an inborn error of vitamin D metabolism, is described in two sisters. The rachitic disorder began during the first year of life and was refractory to 50,000 IU of vitamin D2/day. Surprisingly, both children had marked elevations in serum concentrations of 1,25-(OH)2D. Although the molecular basis for this disorder is not evident to date, intestinal end-organ unresponsiveness to exceedingly high levels of 1,25-(OH)2D was present, in addition to hyporesponsiveness of bone to these high levels of the hormone, since normocalcemia was maintained despite elevated serum levels of PTH. Therapy with oral 1,25-(OH)2D3 failed to reverse the disorder, but oral phosphorus supplements resulted in significant radiographic and clinical improvement.
Asunto(s)
Alopecia/complicaciones , Hipofosfatemia Familiar/complicaciones , Errores Innatos del Metabolismo/complicaciones , Vitamina D/metabolismo , Alopecia/genética , Alopecia/metabolismo , Calcio/metabolismo , Niño , Preescolar , Dihidroxicolecalciferoles/sangre , Dihidroxicolecalciferoles/uso terapéutico , Femenino , Humanos , Hipofosfatemia Familiar/genética , Hipofosfatemia Familiar/metabolismo , Errores Innatos del Metabolismo/genética , Errores Innatos del Metabolismo/metabolismo , Fenotipo , Fósforo/metabolismo , Fósforo/uso terapéuticoAsunto(s)
Dihidroxicolecalciferoles/uso terapéutico , Hidroxicolecalciferoles/uso terapéutico , Hipocalcemia/prevención & control , Enfermedades del Prematuro/prevención & control , Calcio/metabolismo , Dihidroxicolecalciferoles/farmacología , Humanos , Hidroxicolecalciferoles/sangre , Recién Nacido , Absorción Intestinal/efectos de los fármacos , Magnesio/sangre , Hormona Paratiroidea/sangre , Fósforo/sangre , Estudios ProspectivosRESUMEN
Two children who were receiving maintenance hemodialysis were treated with 1 to 4 microng/day of 1 alpha-hydroxyvitamin D3 for 500 to 700 days, respectively. Sequential parathyroid hormone levels and radiologic evaluations showed considerable improvement in one patient. The second patient initially responded with healing of the bone disease. Subsequent deterioration may be related either to medical noncomplicance and/or interference by diphenylhydantoin in the subsequent hepatic 25-hydroxylation of 1 alpha-OH-D3.