Bioelectrical impedance vector analysis for evaluating zinc supplementation in prepubertal and healthy children.

BACKGROUND: The prevalence of abnormal nutritional status has increased in children and adolescents. Nutritional assessment is important for monitoring the health and nutritional status. Bioelectrical impedance vector analysis (BIVA) combines changes in tissue hydration and structure and body composition that can be assessed. OBJECTIVES: The objective of this study was to use BIVA to evaluate nutritional status in 60 prepubertal children, aged between 8 and 9 years, supplemented with zinc, to detect possible changes in body composition. DESIGN: We performed a randomized, controlled, triple-blind study. The children were divided into the control group (CG; sorbitol 10%, n=29) or the experimental group (EG; 10 mg Zn/day, n=31), and the duration of the experiment was 3 months. Anthropometric assessments were performed for all of the children. RESULTS: The body mass index-for-age increased after oral zinc supplementation in the EG (p=0.005). BIVA indicated that the CG demonstrated a tendency for dehydration and decreased soft tissue and the EG demonstrated a tendency for increased soft tissue, primarily the fat-free mass. After analyses of BIVA ellipses, we observed that this method could detect improvements in body composition in healthy children supplemented with zinc. CONCLUSIONS: These results suggest that BIVA could be an auxiliary method for studying a small population undergoing zinc intervention.

Effect of Zinc Supplementation on GH, IGF1, IGFBP3, OCN, and ALP in Non-Zinc-Deficient Children.

OBJECTIVE: Because most publications on growth and development deal with children with zinc deficiency, we decided to study the effects of this micronutrient on the secretion of growth hormone (GH), insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3), osteocalcin (OCN), and alkaline phosphatase (ALP) in healthy and eutrophic children. This study is original because the methodology was unique. METHODS: Forty schoolchildren participated in the study, 17 females and 23 males, aged 8 and 9 years. The study was carried out during a 3-month period. It was characterized as a triple-blind randomized controlled trial. The children were divided in a control group (20 schoolchildren using 10% sorbitol) and experimental group (20 schoolchildren using zinc). All were submitted to oral zinc supplementation (10 mg Zn/day) and venous zinc administration (0.06537 mg Zn/kg of body weight). Blood samples were collected at 0, 60, 120, 180, and 210 min. All schoolchildren were also submitted to anthropometric, clinical, and dietetic assessments as well as biochemistry analyses. RESULTS: Oral zinc supplementation in the experimental group (1) stimulated an increase in the consumption of protein and fat (p = 0.0007, p < 0.0001, p < 0.0001, respectively), (2) increased basal serum zinc (p < 0.0001), (3) increased plasma ALP (p = 0.0270), and (4) showed a positive correlation for IGF1, IGFBP3, and OCN, comparing before and after oral zinc supplementation (p = 0.0011, p < 0.0001, p < 0.0446, respectively). During zinc administration, plasma IGF1 and IGFBP3 increased significantly in the experimental group (p = 0.0468, p < 0.0001, respectively). Plasma GH increased in the experimental group but without statistical difference comparing before and after oral zinc supplementation. CONCLUSIONS: Zinc supplementation stimulated an increase in the consumption of some macronutrients and basal serum zinc and improved plasma alkaline phosphatase levels. Zinc administration increased hormones of the GH-IGF1 system.

Oral zinc supplementation may improve cognitive function in schoolchildren.

Zinc is an important micronutrient for humans, and zinc deficiency among schoolchildren is deleterious to growth and development, immune competence, and cognitive function. However, the effect of zinc supplementation on cognitive function remains poorly understood. The purpose of our study was to evaluate the effect of oral zinc supplementation (5 mg Zn/day for 3 months) on the Full Scale Intelligence Quotient (FSIQ), Verbal Intelligence Quotient (VIQ), and Performance Intelligence Quotient (PIQ) using a Wechsler Intelligence Scale for Children (WISC-III). We studied 36 schoolchildren aged 6 to 9 years (7.8 ± 1.1) using a nonprobability sampling method. The baseline serum zinc concentrations increased significantly after zinc supplementation (p < 0.0001), with no difference between sexes. Tests were administered under basal conditions before and after zinc supplementation, and there was no difference in FSIQ according to gender or age. The results demonstrated that zinc improved the VIQ only in the Information Subtest (p = 0.009), although the supplementation effects were more significant in relation to the PIQ, as these scores improved for the Picture Completion, Picture Arrangement, Block Design, and Object Assembly Subtests (p = 0.0001, for all subtests). In conclusion, zinc supplementation improved specific cognitive abilities, thereby positively influencing the academic performance of schoolchildren, even those without marginal zinc deficiency.

Positive effects of zinc supplementation on growth, GH, IGF1, and IGFBP3 in eutrophic children.

Zinc is an essential micronutrient for growth and development. Its deficiency causes growth retardation in children and adolescents. The present study analyzes the effect of zinc on growth hormone (GH) secretion, insulin-like growth factor 1 (IGF1), and insulin-like growth factor-binding protein 3 (IGFBP3) in normal children before puberty. Thirty normal children were studied, 15 boys and 15 girls, aged 6-9 years. They were orally supplemented with 5 mg Zn/day for 3 months and 0.06537 mg Zn/kg body weight was injected before and after oral supplementation. Dietary intake and anthropometric measurements were assessed at baseline and end of study. Plasma GH levels increased during intravenous zinc administration and IGF1 and IGFBP3 increased after oral zinc supplementation. There was a positive correlation between the areas under the curves of GH and zinc after oral supplementation. Zinc supplementation was possibly effective in improving the body zinc status of the children, secretory levels of IGF1 and IGFBP3, GH potentialization, and height.

Efeito do congelamento sobre a concentração de retinol em fígado de codorna / Effect of freezing procedure on the retinol concentration in liver quail

A deficiência de vitamina A tem sido caracterizada como problema de saúde pública nos países em desenvolvimento. Contudo, a ingestão de alta quantidade de vitamina A pode resultar em efeitos tóxicos e teratogênicos. Neste estudo foi analisado o efeito do congelamento sobre os níveis de retinol em fígado de codorna, utilizando-se a cromatografia líquida de alta eficiência (CLAE). Avaliou-se, também, sua contribuição para a ingestão dietética recomendada a crianças, homens e mulheres. Os valores médios de retinol nas amostras frescas e congeladas de fígado de codorna foram, respectivamente, de 6145,7 μg/100ge 5105,5 μg/100g. O congelamento do fígado causou redução significativa nos níveis de retinol, com perda de 17. Quanto à ingestão dietética de referência (DRI) de retinol para crianças de 1 a 3 anos e de 4 a 8 anos, um fígado de codorna, que equivale a 6 g, contribui, respectivamente, com 123 e 92, o que mostra que o consumo de um fígado de codorna ultrapassa os limites de ingestão diária dessa população. Em indivíduos adultos, esse alimento contribuiu com 41 das necessidades diárias para homens e com 52 para mulheres, o que indica que o fígado de codorna representa ótima fonte de vitamina A.