Calcium plus vitamin D supplementation during pregnancy reduces postpartum fat mass in adolescents: A randomized trial.

BACKGROUND: Pregnancy during adolescence may increase the risk of overweight/obesity. There is evidence that increasing calcium intake, alone or vitamin D-combined, may favor loss of weight and/or fat mass. OBJECTIVES: We hypothesized that calcium supplementation during pregnancy reduces excessive fat accumulation during postpartum period. We aimed to investigate the effect of calcium plus vitamin D supplementation during pregnancy on body composition measurements throughout 1 year postpartum in Brazilian adolescents with habitually low calcium intake (~600 mg/day). METHODS: Adolescents (14-19 years) were randomly assigned to receive a daily supplement (600 mg of calcium plus 200 UI of cholecalciferol, n = 30) or a placebo (n = 26) from 26 weeks of gestation until parturition. Body composition was determined at 5, 20, and 56 weeks postpartum by dual-energy x-ray absorptiometry. The effects of intervention group, time point, as well as their interaction were assessed using repeated measures mixed-effects models. RESULTS: In the adjusted analysis, those supplemented showed lower total body mass [mean difference = -3.32 kg; confidence interval (CI) 95% -6.12 to -0.52 kg], trunk (-1.25 kg; CI 95% -2.34 to -0.15 kg), android (-0.29 kg; CI 95% -0.53 to -0.04 kg) and subcutaneous (-0.23 kg; CI 95% -0.43 to -0.03 kg) fat masses. In the supplemented group, BMI and postpartum weight retention significantly decreased from 5 to 20 weeks (-0.90 kg/m2 and -1.76 kg, respectively; p < .05). At 56 weeks, BMI was still lower (-1.22 kg/m2 ; p < .05) than 5 weeks. CONCLUSIONS: Our findings suggest that increasing calcium intake through supplementation in combination with vitamin D contributes to a more pronounced reduction in total body mass overtime, mostly as a consequence of fat mass reductions in central body regions. This trial was registered at clinicaltrials.gov as NCT01732328.

Maternal zinc intakes and homeostatic adjustments during pregnancy and lactation.

Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating effects, systematic reviews and meta-analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit. We hypothesize, therefore, that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and, therefore, mitigate immediate detrimental effects due to a low zinc intake. The specific questions addressed are the following: How is zinc utilization altered during pregnancy and lactation? Are those homeostatic adjustments influenced by maternal zinc status, dietary zinc, or zinc supplementation? These questions are addressed by critically reviewing results from published human studies on zinc homeostasis during pregnancy and lactation carried out in different populations worldwide.

Plasma zinc, copper, and serum thyroid hormones and insulin levels after zinc supplementation followed by placebo in competitive athletes.

Intense physical activity is associated with biological adaptations involving hormones and trace elements. Zinc supplementation may affect plasma copper concentration, thyroid-stimulating hormone (TSH), thyroid hormones, insulin, and glucose homeostasis, but data in athletes are scarce. The aim of this study was to evaluate in competitive athletes (cyclists, n = 7, 32 ± 8 years) the effect of zinc supplementation (22 mg/day as zinc gluconate) during 30 days, and discontinuation using placebo (maltodextrin) during the following 30 days, on plasma zinc and copper concentrations, serum thyroid hormones, insulin and glucose levels, and HOMA2-IR. Compared to baseline, plasma zinc and Zn:Cu plasma ratio increased, but plasma copper decreased after zinc supplementation (day 30) and discontinuation (day 60) (p < 0.05). Zn supplementation and discontinuation had no effect on TSH, T3, and T4. Fasting serum insulin and HOMA2-IR increased (27% and 47%, respectively) on day 60 compared to baseline (p = 0.03), suggesting a delayed effect of zinc supplementation. Moreover, plasma zinc was positively associated with serum insulin (r = 0.87, p = 0.009) and HOMA2-IR (r = 0.81, p = 0.03) after zinc supplementation (day 30), indicating that supplemental zinc may impair glucose utilization in cyclists.

Effect of zinc supplementation on the antioxidant, copper, and iron status of physically active adolescents.

Puberty associated with intense physical activity results in oxidation stress. Zinc supplementation may benefit antioxidant capacity although it may also affect iron and copper status. This study evaluated the effect of zinc supplementation on antioxidant, zinc and copper status of physically active male football players (13 years +/- 0.4 years), divided in two groups and studied during 12 weeks: Zn-supplemented (Zn-SUP, 22 mg Zn d(-1) as zinc gluconate, n = 21) and placebo (PLA, n = 26). At baseline, there was no significant difference in biochemical indices between the two groups. After treatment, plasma zinc and erythrocyte iron increased in both groups (p < 0.001); urinary zinc increased (p < 0.001) only in Zn-SUP, and erythrocyte zinc decreased (p = 0.002) only in PLA. Plasma iron and copper decreased (p = 0.01 and p = 0.015, respectively) only in Zn-SUP. Plasma ferric-reducing ability and plasma conjugated dienes increased, and erythrocyte osmotic fragility decrease in both groups, although the latter two were significantly lower in Zn-SUP compared to PLA (p < 0.01). In conclusion, our study indicates that the use of 22 mg d(-1) of supplemental zinc during 12 week in adolescent athletes did not affect growth, improved markers of antioxidant status but reduced plasma iron and copper. Therefore, it appears that the use of zinc supplementation by healthy adolescent athletes benefits their antioxidant capacity but impairs copper and iron nutritional status.

Plasma leptin, plasma zinc, and plasma copper are associated in elite female and male judo athletes.

The purpose of this study was to compare plasma leptin, plasma zinc, and plasma copper levels and their relationship in trained female and male judo athletes (n = 10 women; n = 8 men). Blood samples were obtained 24 h after training to measure plasma zinc, copper, and leptin levels. Subjects presented similar values to age (22 +/- 2 years old), body mass index (24 +/- 1 kg/m(2)), plasma zinc (17.2 +/- 2 micromol/L), copper (12.5 +/- 2 micromol/L), and leptin (5.6 +/- 1.3 microg/L). However, height, total body mass, lean mass, fat mass, and sum of ten-skinfold thickness were higher in male than female. Plasma leptin was associated with sum of ten skinfolds in male (r = 0.91; p < 0.001) and female athletes (r = 0.84; p < 0.003). Plasma zinc was associated with leptin in males (r = 0.82; p < 0.05) while copper was associated with plasma leptin in females (r = 0.66; p < 0.05). Our results suggest that young judo athletes lost sex-related differences in leptin levels. Plasma zinc, plasma copper, and energy homeostasis may be involved in regulation of plasma leptin.

Fatores associados ao consumo de café de trabalhadores atendidos pelo Programa de Alimentação do Trabalhador de Belém, Pará, Brasil / Coffee consumption associated factors among workers covered by the Workers' Food Program from Belém, Pará, Brazil

Objetivo. Devido ao elevado consumo de café no Brasil e às novas perspectivas quanto aos efeitos de sua ingestão à saúde, esse trabalho teve por objetivo avaliar as associações entre o consumo de café e os aspectos socioeconômicos, comportamentais e padrões alimentares de trabalhadores de empresas conveniadas ao Programa de Alimentação do Trabalhador, Belém, Pará, Brasil. Método. Trata-se de um estudo transversal com amostra de 1.054 trabalhadores, 69% do sexo masculino. O consumo de café e dos grupos de alimentos foi obtido por meio de um questionário de frequência alimentar semi-quantitativa. Resultados. Verificou-se tendência crescente e significativa da proporção de consumidores de café à medida que houve aumento na ingestão dos grupos de carnes e ovos (p = 0,04), óleos e gorduras (p = 0,003), e petiscos e lanches (p = 0,02). Houve diferença estatística significativa entre os grupos de consumo de café e as variáveis fumo (p = 0,04), aumento da idade (p = 0,006) e sexo feminino (p = 0,01). Não houve associação significativa com os demais parâmetros estudados. Conclusão. O consumo de café tem maior frequência em indivíduos com o consumo de alimentos protéicos e com maior densidade energética e está associado à idade, sexo e tabagismo.

Objective. Due to the high consumption of coffee in Brazil and the new perspectives on the health effects resulting from its intake, this study aims to assess associations between coffee consumption and dietary, and socio-economicbehavioralpatterns among workers from companies affiliated to the Programa de Alimentação do Trabalhador (Workers’ Food Program) in the city of Belém, in the state of Pará, Brazil. Method. This is a cross-sectional study with a sample of 1,054 workers, of which 69% were males. Consumption of coffee and other food groups was obtained by means of a semi-quantitative food frequency questionnaire. Results. It is shown that the number of coffee drinkers grew significantly as consumption of the meat and egg (p= 0.04), fat and oil (p = 0.003), and snack food groups (p = 0.02) increased. There was significant difference among coffee intake groups with tabagism (p = 0.04), age (p = 0.006) and sex (p = 0.01). There was no significant association with the remaining parameters analyzed. Conclusion. Coffee consumption is more likely to occur with the intake of high-energy, protein-rich foods; and is associated with age, sex and tabagism.

Supplementing young women with both zinc and iron protects zinc-related antioxidant indicators previously impaired by iron supplementation.

Iron supplementation impairs antioxidant status, whereas zinc is recognized as an antioxidant micronutrient. We investigated the effect of supplementing both zinc and iron on iron, zinc, and antioxidant status in 18 women (22-31 y) studied during 2 sequential 8-wk periods. From wk 1 to 8, only iron (50 mg/d) (Fe period) was supplemented and from wk 9 to 16, zinc (25 mg/d) (Fe+Zn period) was also given but at a different time of the day. Indicators of iron (serum iron, iron-binding capacity, and serum ferritin), zinc (serum and urinary zinc), and antioxidant status [ferric-reducing ability of plasma (FRAP); erythrocyte osmotic fragility (EOF); erythrocyte aminolevulinic acid dehydratase (delta-ALAD) activity, and in vitro zinc-delta-ALAD activation (Zn-delta-ALAD%)] were measured at baseline and after each supplementation period. Fe period modified indicators of iron status as expected (P < 0.05) but did not affect indicators of zinc status. Fe+Zn period did not affect indicators of iron status but increased serum and urinary zinc (P < 0.02). Antioxidant status was impaired after the Fe period, as indicated by decreased FRAP (P < 0.005) and delta-ALAD activity (P < 0.05) and increased EOF (P < 0.01). After the Fe+Zn period, FRAP values tended to increase (P = 0.1), delta-ALAD activity and EOF returned to baseline values, and Zn-delta-ALAD% decreased (P < 0.001) compared with baseline. In conclusion, supplementing young women with both zinc and iron protects zinc-related antioxidant indicators previously impaired by iron supplementation without impairment of iron status.