RESUMEN
During lactation maternal losses of calcium and phosphorus through human milk average 220 to 340 and 110 to 170 mg/day, respectively. The present study reports maternal serum concentrations of vitamin D metabolites, parathyroid hormone, calcitonin, calcium, magnesium, and phosphorus during the first 6 months of lactation. Serum calcium and magnesium concentrations increased during the first 6 months of lactation. Serum 1,25-(OH)2 vitamin D was increased at 6 months of lactation compared to values in nonpregnant nonlactating controls. During this same period, serum parathyroid hormone decreased slightly and serum calcitonin remained unchanged. Our data do not support the observation that lactation represents a state of physiological hyperparathyroidism. On the contrary, our results suggest that lactating women are able to adequately compensate for the losses of calcium and phosphorus during the early months of lactation, although increased serum 1,25-(OH)2 vitamin D concentrations may be necessary to maintain calcium homeostasis with lactation beyond 6 months.
Asunto(s)
Calcitonina/sangre , Calcitriol/sangre , Hidroxicolecalciferoles/sangre , Lactancia , Hormona Paratiroidea/sangre , Calcifediol , Calcio/sangre , Femenino , Homeostasis , Humanos , Magnesio/sangre , Fósforo/sangre , Periodo Posparto , Embarazo , Factores de TiempoAsunto(s)
Huesos/metabolismo , Lactancia Materna , Ergocalciferoles/análogos & derivados , Minerales/metabolismo , Vitamina D/administración & dosificación , 25-Hidroxivitamina D 2 , Ergocalciferoles/sangre , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Leche Humana/metabolismo , Distribución Aleatoria , Luz SolarRESUMEN
Eighteen term, healthy, appropriate for gestational age, breast-fed infants were studied in a double-blind prospective study to determine whether or not supplemental vitamin D affected bone mineralization. All patients were from a single, private pediatric practice. Nine infants were randomly assigned to a vitamin D supplement of 400 IU/day and nine infants to a placebo. By 12 weeks of age, infants receiving placebo had a significant decrease in bone mineralization and in serum 25-hydroxyvitamin D concentrations compared to the vitamin D-supplemented group. It is not known whether or not the increased BMC at 12 weeks of age in vitamin D-supplemented breast-fed infants is of ultimate value. Supplemental vitamin D may be necessary for optimal bone mineralization in term breast-fed infants. A longer follow-up study and additional analyses are required to make conclusive statements.