RESUMO
OBJECTIVE: To determine whether children with calcium-deficiency rickets respond better to treatment with calcium as limestone or as ground fish. STUDY DESIGN: Nigerian children with active rickets (n = 96) were randomized to receive calcium as powdered limestone (920 mg of elemental calcium) or ground fish (952 mg of elemental calcium) daily for 24 weeks. Radiographic healing was defined as achieving a score of 1.5 or less on a 10-point scale. RESULTS: The median (range) age of enrolled children was 35 (6-151) months. Of the 88 children who completed the study, 29 (66%) in the ground fish group and 24 (55%) in the limestone group achieved the primary outcome of a radiographic score of 1.5 or less within 6 months (P = .39). The mean radiographic score improved from 6.2 ± 2.4 to 1.8 ± 2.2 in the ground fish group and from 6.3 ± 2.2 to 2.1 ± 2.4 in the limestone group (P = .68 for group comparison). In an intention to treat analysis adjusted for baseline radiographic score, age, milk calcium intake, and serum 25-hydroxyvitamin D concentration, the response to treatment did not differ between the 2 groups (P = .39). Younger age was associated with more complete radiographic healing in the adjusted model (aOR 0.74 [95% CI 0.57-0.92]). After 24 weeks of treatment, serum alkaline phosphatase had decreased, calcium and 25-hydroxyvitamin D increased, and bone mineral density increased in both groups, without significant differences between treatment groups. CONCLUSION: In children with calcium-deficiency rickets, treatment with calcium as either ground fish or limestone for 6 months healed rickets in the majority of children.
Assuntos
Carbonato de Cálcio/administração & dosagem , Suplementos Nutricionais , Produtos Pesqueiros , Raquitismo/terapia , Fatores Etários , Fosfatase Alcalina/sangue , Densidade Óssea , Cálcio/sangue , Cálcio/deficiência , Criança , Pré-Escolar , Dessecação , Feminino , Humanos , Lactente , Masculino , Nigéria , Pós , Radiografia , Rádio (Anatomia)/diagnóstico por imagem , Raquitismo/diagnóstico por imagem , Ulna/diagnóstico por imagem , Vitamina D/análogos & derivados , Vitamina D/sangueRESUMO
OBJECTIVE: To determine whether calcium supplementation alters the risk of lead toxicity. STUDY DESIGN: Children aged 12-18 months from 3 communities in Nigeria were assigned to receive daily calcium supplementation, as either calcium carbonate (400 mg) or ground dried fish (529 ± 109 mg), or placebo. All children received 2500 IU of vitamin A. Levels of blood lead, calcium, and vitamin D metabolites were measured at baseline and after 12-18 months (n = 358). RESULTS: The mean (± SD) baseline lead level was 11.1 ± 7.8 µg/dL (range, 1-43 µg/dL; median, 9 µg/dL); 44.7% of subjects had a lead level >10 µg/dL. After 12-18 months, the mean lead level was 8.1 ± 6.3 µg/dL (range, 1-48 µg/dL; median, 6 µg/dL), with 22.6% with a level >10 µg/dL. Lead levels at baseline varied among communities (P = .01) and were higher in children who used eye cosmetics or lived near a lead-acid battery melter (both P < .001). In a multiple regression model, the decrease in blood lead level was predicted by age, baseline lead level, and time of final lead value at 12-18 months (R(2) = 31%), but not by calcium supplementation (P = .98). CONCLUSIONS: Lead toxicity is common in Nigerian children, but calcium supplementation does not affect blood lead levels.
Assuntos
Carbonato de Cálcio/uso terapêutico , Suplementos Nutricionais , Produtos Pesqueiros , Alimentos Formulados , Chumbo/sangue , Fatores Etários , Cosméticos , Fontes de Energia Elétrica , Feminino , Humanos , Lactente , Masculino , Análise Multivariada , Nigéria , Características de Residência , Vitamina A/uso terapêutico , Vitaminas/uso terapêuticoRESUMO
OBJECTIVE: To test the hypothesis that rapid infant weight gain is associated with advanced skeletal maturity in children from the United States and South Africa. STUDY DESIGN: Longitudinal data from 467 appropriate-for-gestational-age infants in the Fels Longitudinal Growth Study (Dayton, Ohio) and 196 appropriate-for-gestational-age infants in the Birth to Twenty birth cohort study (Johannesburg, South Africa) were used. Multiple linear regression models tested the association between internal SD score change in weight from 0 to 2 years and relative skeletal age at 9 years, adjusting for body mass index, stature, and other covariates. RESULTS: In both studies, faster infant weight gain was associated with more advanced skeletal maturity (approximately 0.2 years or 2.4 months per SD score) at age 9 years (P <.0001-.005), even when adjusting for the positive associations of both birth weight and body mass index at age 9 years. This effect appeared to be accounted for by the greater childhood stature of subjects with more rapid infant weight gain. CONCLUSIONS: Relatively rapid infant weight-gain is associated with advanced skeletal development in late childhood, perhaps via effects on stature.
Assuntos
Desenvolvimento Ósseo/fisiologia , Aumento de Peso/fisiologia , Adolescente , Fatores Etários , Peso ao Nascer , Índice de Massa Corporal , Tamanho Corporal , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , África do Sul , Estados Unidos , Adulto JovemRESUMO
OBJECTIVE: To assess the effect of vitamin D(2) administration on serum vitamin D metabolite concentrations in calcium deficiency rickets. STUDY DESIGN: We administered vitamin D(2), 50,000 IU orally to 16 Nigerian children 15 to 48 months of age with radiographically active rickets. We measured calcium and vitamin D metabolites at baseline and at 1, 3, 7, and 14 days. RESULTS: At baseline, ranges of serum 25-hydroxyvitamin D (25(OH)D) concentrations were 18 to 40 nmol/L (7-16 ng/mL), and 1,25-dihydroxyvitamin D (1,25-(OH)(2)D) concentrations were 290 to 790 pmol/L (120-330 pg/mL). After vitamin D administration, serum 25(OH)D and 1,25(OH)(2)D concentrations rapidly rose and peaked at 2.8 and 1.9 times the baseline values (P < .001), respectively, at 3 days. Positive correlations between 1,25(OH)(2)D and 25(OH)D were strongest at day 3 (r = 0.84, P < .001) and weakest at day 14 (r = 0.41, P = .11). The relationship of 1,25(OH)(2)D with 25(OH)D at baseline and the increase in 1,25(OH)(2)D in response to vitamin D were similar to those described in children with vitamin D deficiency. However, unlike the pattern in vitamin D deficiency, 1,25(OH)(2)D remained positively correlated with 25(OH)D after administration of vitamin D. CONCLUSION: Dietary calcium deficiency increases the demand for 25(OH)D above that required in vitamin D deficiency to optimize 1,25(OH)(2)D concentrations. Assessment of vitamin D sufficiency in persons or communities may need to be adjusted for habitual dietary calcium intake.