Reduction in Bone Loss from 5 to 20 Weeks Postpartum in Adolescents Supplemented with Calcium Plus Vitamin D during Pregnancy Is Not Sustained at 1 Year Postpartum: Follow-up Study of a Randomized Controlled Trial.

BACKGROUND: Calcium plus vitamin D supplementation of pregnant Brazilian adolescents with habitually low calcium intake (∼600 mg/d) reduced bone loss during the first 20 wk postpartum. OBJECTIVE: We investigated maternal bone mass changes during the first year postpartum as a follow-up of the clinical trial. METHODS: Pregnant adolescents (14-19 y) received calcium (600 mg/d) plus cholecalciferol (200 IU/d) supplementation (n = 30) or placebo (n = 26) from 26 wk of gestation until parturition. Bone area and bone mineral content and bone mineral density (BMD) at total body, lumbar spine, and hip (total and femoral neck) were assessed by DXA at 3 time points postpartum (5 wk, 20 wk, and 56 wk). Intervention group, time postpartum, and group × time interaction effects were tested by repeated-measures mixed-effects models adjusting for calcium intake, return of menses, breastfeeding practices, and body weight. RESULTS: Time (P < 0.05) but not group affected several absolute bone measurements. There was a group × time interaction for femoral neck BMD (P = 0.045). Mean ± SE values (g/cm2) at 5 wk, 20 wk, and 56 wk were, respectively, 1.025 ± 0.026, 0.980 ± 0.026, and 1.022 ± 0.027 for the placebo group and 1.057 ± 0.025, 1.030 ± 0.024, and 1.055 ± 0.025 for the supplemented group. An interaction also was observed for percentage change in femoral neck BMD relative to 5 wk (P = 0.049), with a more pronounced decrease in the placebo group (-4.58 ± 0.42%) than in the supplemented group (-3.15% ± 0.42%) at 20 wk (P = 0.019), and no difference between groups at 56 wk (-0.44% ± 0.71% in the placebo and -0.76% ± 0.62% in the supplemented group; P = 0.65). CONCLUSIONS: Calcium plus vitamin D supplementation of the adolescent mothers reduces the magnitude of bone loss at the femoral neck from 5 to 20 wk postpartum without an effect on bone changes after 1 y postpartum, indicating that there is no sustained effect of the supplement tested.

Lead exposure and indices of height and weight in Uruguayan urban school children, considering co-exposure to cadmium and arsenic, sex, iron status and dairy intake.

Child growth depends on complex factors including diet, nutritional status, socioeconomic, and sanitary conditions, and exposure to environmental chemicals. Lead exposure is known to impair growth in young children but effects in school-age children are less clear. The effects of co-exposure to low-level lead and other toxic metals on child growth are not well understood. We examined cross-sectional associations of blood lead (BLL) with growth indices (Z scores of body mass index for age, BAZ, and height for age, HAZ) in Uruguayan urban school children (n = 259; ~7 y). Potential differences in these associations in children with lower vs. higher urinary inorganic arsenic metabolites (U-As), urinary cadmium (U-Cd), sex (42% girls), iron deficiency (ID, 39% children), or intake of dairy foods below recommended levels were examined. BLL was measured using AAS, U-As using HPLC-HGICP-MS, and U-Cd using ICP-MS. Dietary information was obtained by two 24-h recalls completed by caregivers. Children's linear growth was within age and sex-appropriate reference values. Overweight (BAZ > 1 2 SD) was found in 20.1%, and obesity (BAZ > 2 SD) in 18.5%, of children. Ranges (5th, 95th percentile) of biomarker concentrations were: BLL, 0.8-7.8 µg/dL; U-Cd, 0.01-0.2 µg/L, and U-As, 4.0-27.3 µg/L. BLL was inversely associated with HAZ ([95% CI]: 0.10 [-0.17, -0.03]) in covariate-adjusted models. Although this association was slightly more pronounced in girls, children without ID, and children with lower U-As, there was little evidence of effect modification due to overlapping CIs in stratified models. BLLs were not associated with BAZ, except for a suggestion of a negative relationship in girls (-0.10 [-0.23, 0.02]) but not boys [0.001 [-0.11, 0.12]). Our findings indicate that exposure to low levels of lead was associated with lower HAZ in apparently normally growing urban school children. Larger future studies should help elucidate if these associations persist over time and across populations.

Calcium plus vitamin D supplementation during pregnancy interacts with polymorphisms in the promoter region of the VDR gene to affect postpartum bone mass of Brazilian adolescent mothers: A randomized controlled trial.

OBJECTIVE: We investigated whether calcium plus vitamin D supplementation interacts with polymorphisms in the VDR gene promoter region to affect changes on maternal bone mass from 5 to 20 wk postpartum in Brazilian adolescent mothers. METHODS: Pregnant adolescents (14-19 y) randomly received calcium plus cholecalciferol (600 mg/d + 200 IU/d, n = 30) or placebo (n = 26) from 26 wk of pregnancy until parturition. Bone mineral content (BMC), bone area (BA), and bone mineral density (BMD) at total body, lumbar spine, total hip, and femoral neck were evaluated at 5 and 20 wk postpartum. Serum 25-hydroxyvitamin D (25[OH]D) and parathyroid hormone concentrations were measured. Real-time polymerase chain reaction was used for genotyping rs7139166 (1521 pb G > C) and rs4516035 (1012 pb A > G). Interactions between supplementation and polymorphisms were adjusted for significant covariates. RESULTS: Changes in serum 25(OH)D from pregnancy to postpartum differed between supplemented and placebo groups for mothers carrying 1521 GG/1012 AA genotypes (P = 0.004). Only in the placebo group, mothers carrying 1521 GG/1012 AA had greater reduction in total BMD z score, femoral neck BMC, and BMD from 5 to 20 wk postpartum compared with those with 1521 GC/1012 AG (P < 0.05). In the placebo group, total hip BA decreased from 5 to 20 wk postpartum in adolescents with 1521 GG/1012 AA, but increased in those with 1521 GC/1012 AG (P < 0.05), in contrast to the supplemented group. CONCLUSION: Calcium plus vitamin D supplementation during pregnancy interacted with polymorphisms in the VDR gene promoter region affecting postpartum bone loss. The increased supply of calcium and vitamin D appeared to minimize postpartum bone loss particularly in adolescents with 1521 GG/1012 AA.

Calcium Plus Vitamin D Supplementation During the Third Trimester of Pregnancy in Adolescents Accustomed to Low Calcium Diets Does Not Affect Infant Bone Mass at Early Lactation in a Randomized Controlled Trial.

BACKGROUND: Pregnancy and lactation in adolescents with low calcium intake may impair fetal growth and infant bone mass. OBJECTIVE: We investigated the effects of calcium plus vitamin D supplementation during pregnancy in Brazilian adolescent mothers consuming low calcium diets (∼600 mg/d) on fetal biometry and infant bone mass, and the relation between infant and maternal bone mass during early lactation. METHODS: Infants of mothers who received calcium (600 mg/d) plus cholecalciferol (200 IU/d) supplementation (n = 30) or placebo (n = 26) from 26 wk of gestation until parturition were studied. Fetal biometric measurements at 23 and 36 wk of gestation were obtained from medical records. Infant anthropometric and total body bone measurements [bone mineral content (BMC), bone area (BA), and bone mineral density (BMD)] at 5 wk postpartum were assessed by dual-energy X-ray absorptiometry. Maternal BMD z scores for total body, lumbar spine, total hip, and femoral neck at 5 wk postpartum were obtained. Group comparisons were adjusted for significant covariates. RESULTS: Maternal mean serum 25-hydroxyvitamin D was 59 nmol/L at baseline in both groups. No differences in fetal measurements at 36 wk of gestation were observed between the groups, except for body weight and its increment from 23 to 36 wk, which were higher in the supplemented group (6.8%, P = 0.014 and 10.5%, P = 0.07, respectively). Infant BMC (61.1 ± 21.7 g), BA (167 ± 79 cm(2)), and BMD (0.385 ± 0.069 g/cm(2)) did not significantly differ between the groups. In the placebo group, infant BMC and BA were negatively correlated with maternal BMD z scores for total body (r = -0.40 and r = -0.47; P < 0.05) and hip (r = -0.41 and r = -0.46; P < 0.05). In contrast, no correlations were observed in the supplemented group. CONCLUSIONS: Calcium and vitamin D supplementation of the adolescents studied resulted in higher fetal body weight at 36 wk of gestation and had no effect on infant bone mass at 5 wk postpartum. Because correlations between maternal and infant bone mass were evident only in the placebo group, infant bone mass appeared to be more dependent on maternal skeletal mass when calcium intake was low. This trial was registered at clinicaltrials.gov as NCT01732328.

Effect of calcium plus vitamin D supplementation during pregnancy in Brazilian adolescent mothers: a randomized, placebo-controlled trial.

BACKGROUND: Pregnancy and lactation in adolescents with habitually low calcium intake may adversely affect maternal bone mass. OBJECTIVE: We investigated the effect of calcium plus vitamin D supplementation during pregnancy on bone mass during lactation in Brazilian adolescent mothers with low-calcium diets (∼600 mg/d). DESIGN: Pregnant adolescents (14-19 y) randomly received daily calcium (600 mg) plus vitamin D3 (200 IU) (n = 30) or a placebo (n = 26) from 26 wk of pregnancy (baseline) until parturition. The bone mineral content (BMC), bone area (BA), and bone mineral density (BMD) at the total body, lumbar spine, and hip (total and femoral neck) were evaluated by using dual-energy X-ray absorptiometry at 5 and 20 wk postpartum. Serum hormones and 25-hydroxyvitamin D [25(OH)D] were measured. Group comparisons were adjusted for significant covariates. RESULTS: The mean serum 25(OH)D concentration was 59 nmol/L at baseline. In comparison with the placebo, 25(OH)D tended to be 14-15 nmol/L higher postpartum in the supplemented group (P = 0.08). Total body and hip BMC and BMD decreased over time (P ≤ 0.005) in both groups with a group × time interaction at the femoral neck (P < 0.04). Supplemented mothers had higher lumbar spine BA (6.7%; P = 0.002) and lumbar spine BMC (7.9%, P = 0.08) than did mothers who consumed the placebo at 5 wk postpartum. At 20 wk postpartum, differences between groups were more evident, with higher lumbar spine BMC (13.9%), lumbar spine BA (6.2%), and lumbar spine BMD (10.6%) in the supplemented group (P ≤ 0.008). CONCLUSIONS: Calcium plus vitamin D supplementation during pregnancy of adolescents with low calcium intake results in higher lumbar spine bone mass and a reduced rate of femoral neck bone loss during lactation. Additional studies are required to determine whether bone effects are temporary or long-lasting. This trial was registered at clinicaltrials.gov as NCT01732328.

Serum 1,25-dihydroxyvitamin D and calcium intake affect rates of bone calcium deposition during pregnancy and the early postpartum period.

BACKGROUND: Factors affecting bone calcium deposition across pregnancy and lactation are not well characterized. OBJECTIVE: The impact of maternal age, calcium intake, race-ethnicity, and vitamin D status on the rate of bone calcium deposition (VO+) was assessed across pregnancy and lactation. DESIGN: Stable calcium isotopes were given to 46 women at pre- or early pregnancy (trimester 1), late pregnancy (trimester 3), and 3-10 wk postpartum. Three cohorts were included: 23 adolescents from Baltimore (MD), aged 16.5 ± 1.4 y (mean ± SD; Baltimore cohort); 13 adults from California, aged 29.5 ± 2.6 y (California cohort); and 10 adults from Brazil, aged 30.4 ± 4.0 y (Brazil cohort). The total exchangeable calcium pool, VO+, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D [1,25(OH)2D], parathyroid hormone, and calcium intake were evaluated. RESULTS: At trimester 3, inverse associations between 1,25(OH)2D and VO+ were evident in the Baltimore (P = 0.059) and Brazil (P = 0.008) cohorts and in the whole group (P = 0.029); calcium intake was not a significant determinant of VO+ in any group during pregnancy. At postpartum, a significant positive association was evident between VO+ and calcium intake (P ≤ 0.002) and between VO+ and African ethnicity (P ≤ 0.004) in the whole group and within the Baltimore and Brazil cohorts. CONCLUSIONS: Elevated 1,25(OH)2D was associated with decreased rates of bone calcium deposition during late pregnancy, a finding that was particularly evident in pregnant adolescents and adult women with low calcium intakes. Higher dietary calcium intakes and African ethnicity were associated with elevated rates of bone calcium deposition in the postpartum period.

Influence of coffee roasting on the incorporation of phenolic compounds into melanoidins and their relationship with antioxidant activity of the brew.

In the present study, the influence of coffee roasting on free and melanoidin-bound phenolic compounds and their relationship with the brews' antioxidant activity (AA), evaluated by TRAP, TEAC, and TRAP, were investigated. Changes in the relative content of free chlorogenic acids (CGA), free lactones, and melanoidin-bound phenolic acids during roasting indicate that phenolic compounds were incorporated into melanoidins mainly at early stages of the process, being thereafter partly oxidized to dihydrocaffeic acid, and degraded. Although less than 1% of CGA in green coffee was incorporated into melanoidins during roasting, the relative content of melanoidin-bound phenolic acids increased significantly during this process, reaching up to 29% of total phenolic compounds in brews from dark roasted coffees. Regardless of the AA assay used and considering all roasting degrees, the overall contribution of CGA to the AA of the whole brews was higher than that of melanoidin-bound phenolic compounds. It was estimated that the latter compounds contributed to 25-47% of the AA, depending on the assay used.

Modeling weight loss and chlorogenic acids content in coffee during roasting.

Roasting is a key step in the production of a high-quality coffee. Roasting degree is directly related to coffee chemical composition and may be determined objectively by weight loss after roasting. Chlorogenic acids (CGA) are thermally labile phenolic compounds that play an important role in the final cup quality and health benefits of coffee. Considering the interest in finding a reliable method to predict weight loss and CGA content in coffee, models have been developed to estimate these parameters during roasting. Weight loss was successfully modeled (r = 0.99) independent of the instant temperature. CGA degradation followed first-order Arrhenius-compliant kinetic models with good predictability (r = 0.98), especially for light to moderately dark samples. In both cases distinct models for Coffea arabica and Coffea canephora were calculated, because of differences in chemical composition and cell wall structure between these species. The proposed models may become important predictive tools in the coffee industry.

Vitamin D receptor gene FokI polymorphisms influence bone mass in adolescent football (soccer) players.

The genetic influence on bone mineralization during adolescence is unclear possibly due to modifying factors such as skeletal maturation and lifestyle. We evaluated the influence of polymorphisms of the vitamin D receptor (VDR) gene on longitudinal changes in bone mass, bone- and calcium-related hormones in 46 adolescent soccer players (11.8-14.2 years). Total body bone mineral content (TBMC) and density (TBMD) were measured at baseline and after 6 months. Insulin-like growth factor-I (IGF-1), testosterone, intact parathyroid hormone, and activity of plasma bone alkaline phosphatase were measured at baseline and after 3 months. The influence of FokI or TaqI VDR genotypes on changes in the outcome variables were analyzed by univariate ANOVA with adjustment for chronological age, skeletal age and body weight at baseline. At baseline, boys with Ff genotype had higher TBMC, TBMD, TBMD Z-score compared to those with FF genotype (P < 0.05). After 3 months, Ff boys also had higher increment in plasma IGF-1 (P < 0.05). FokI polymorphism did not influence changes in bone mass measurements after 6 months, although differences detected at baseline remained significant after 6 months. There were no differences in the outcome variables according to TaqI genotypes. This study demonstrates that FokI polymorphisms affect bone mass in Brazilian adolescent soccer players and suggests that the FokI effect on bone mineralization occurs during bone maturation, possibly at the initial pubertal stages.

The increase in human plasma antioxidant capacity after acute coffee intake is not associated with endogenous non-enzymatic antioxidant components.

This study evaluated the association between the main plasma endogenous non-enzymatic antioxidant components and the increase in human antioxidant capacity (AC) after acute coffee intake. Ten adults were tested before and 90 min after consumption of coffee or water, in a crossover design, with a 7-day interval between tests. AC (FRAP and TRAP), ascorbic acid, α-tocopherol and γ-tocopherol, albumin, bilirubin and uric acid were analyzed in plasma/serum. After coffee consumption FRAP and TRAP increased 2.6% and 7.6% (P<0.05), whereas after water consumption FRAP and TRAP decreased 2.5% and 1.0% (P <0.05), respectively. In general, AC assays correlated with uric acid and α-tocopherol (r >0.75; P <0.04), independently of treatment and time point. Changes in AC assays after coffee intake did not correlate with endogenous components, which remained unchanged. These results suggest that coffee components spare endogenous antioxidants or are themselves the main contributors to plasma AC increase after coffee intake.

Chlorogenic acids from green coffee extract are highly bioavailable in humans.

Chlorogenic acids (CGA) are cinnamic acid derivatives with biological effects mostly related to their antioxidant and antiinflammatory activities. Caffeoylquinic acids (CQA) and dicaffeoylquinic acids (diCQA) are the main CGA found in nature. Because green coffee is a major source of CGA, it has been used for production of nutraceuticals. However, data on the bioavailability of CGA from green coffee in humans are inexistent. The present study evaluated the pharmacokinetic profile and apparent bioavailability of CGA in plasma and urine of 10 healthy adults for 8 h after the consumption of a decaffeinated green coffee extract containing 170 mg of CGA. Three CQA, 3 diCQA, and caffeic, ferulic, isoferulic, and p-coumaric acids were identified in plasma by HPLC-Diode Array Detector-MS after treatment. Over 30% (33.1 +/- 23.1%) of the ingested cinnamic acid moieties were recovered in plasma, including metabolites, with peak levels from 0.5 to 8 h after treatment. CGA and metabolites identified in urine after treatment were 4-CQA, 5-CQA, and sinapic, p-hydroxybenzoic, gallic, vanillic, dihydrocaffeic, caffeic, ferulic, isoferulic, and p-coumaric acids, totaling 5.5 +/- 10.6% urinary recovery of the ingested cinnamic and quinic acid moiteties. This study shows that the major CGA compounds present in green coffee are highly absorbed and metabolized in humans.

Red blood cell metallothionein as an indicator of zinc status during pregnancy.

OBJECTIVE: We describe the levels and patterns of change in red blood cell (RBC) metallothionein (MT) during pregnancy and the neonate and relate RBCMT to other indicators of zinc and iron status. METHODS: As part of a double-masked controlled trial of prenatal zinc supplementation among 242 Peruvian pregnant women, we determined RBCMT at enrollment (10-16 wk), at 28 and 36 wk of gestation, and in the cord blood at delivery in 158 women (86 who received daily supplements containing 60 mg of iron and 250 microg of folic acid and 72 whose supplements also contained 25 mg of zinc). In addition, we measured plasma and urinary zinc concentrations, hemoglobin and serum ferritin, and, on a limited sample, RBC zinc and placental MT. RESULTS: RBCMT increased during pregnancy, and levels in the cord blood approximated maternal values at 36 wk. Only RBC zinc at 36 wk differed by supplement type (P < 0.05). Increases in RBCMT over pregnancy were, however, related to early pregnancy RBC zinc and inversely with the decline in plasma zinc from baseline to 36 wk of gestation. CONCLUSION: Changes in RBCMT throughout pregnancy were consistent with the hypothesized role of MT in regulating zinc homeostasis. RBCMT appears to not be responsive during pregnancy to changes in zinc status achieved with supplements.

Daily supplementation with iron increases lipid peroxidation in young women with low iron stores.

The aim of this study was to determine whether women with low iron stores (plasma ferritin

Bone mass and breast milk calcium concentration are associated with vitamin D receptor gene polymorphisms in adolescent mothers.

Lactation-associated bone loss has been reported in adolescent mothers. Polymorphisms in the vitamin D receptor (VDR) gene may contribute to differences in the physiologic skeletal response to lactation in these mothers. We evaluated the influence of VDR gene polymorphisms ApaI, BsmI, and TaqI on bone mass, bone and calcium-related hormones, and breast milk calcium of lactating adolescents with habitually low calcium intake. Total body bone mineral content (TBMC), total body bone mineral density (TBMD), lumbar spine BMD (LSBMD), serum hormones [intact parathyroid hormone (iPTH), 25-hydroxyvitamin D, insulin-like growth factor-I (IGF1), prolactin, and estradiol), and breast milk calcium were measured in 40 lactating Brazilian adolescents (15-18 y), and compared by VDR genotype subgroups after adjustment for calcium intake and postmenarcheal and lactational periods. TBMD and LSBMD Z scores were -0.55 +/- 1.01 and -1.15 +/- 1.48, respectively. LSBMD was higher (21%; P < 0.05) in adolescents with the aa genotype (n = 5) compared with those with the AA genotype (n = 7). TBMC and IGF1 were higher (23 and 50%, respectively; P < 0.05) in adolescents with tt (n = 4) than those with TT (n = 29) and Tt (n = 7) genotypes. Breast milk calcium and serum iPTH were higher (24 and 80%, respectively; P < 0.05) in adolescents with bb (n = 8) compared with those with BB (n = 21) genotype. These results indicate that bone mass and breast milk calcium are significantly associated with VDR genotypes in lactating Brazilian adolescents. Those with aa and tt genotypes had a better bone status and those with bb genotype had greater breast milk calcium.

Bone calcium turnover during pregnancy and lactation in women with low calcium diets is associated with calcium intake and circulating insulin-like growth factor 1 concentrations.

BACKGROUND: Few data exist on longitudinal changes in bone calcium turnover rates across pregnancy and lactation. OBJECTIVE: Our aim was to characterize calcium kinetic variables and predictors of these changes across pregnancy and early lactation in women with low calcium intakes. DESIGN: Stable calcium isotopes were administered to 10 Brazilian women during early pregnancy (EP; weeks 10-12 of gestation), late pregnancy (LP; weeks 34-36 of gestation), and early lactation (EL; 7-8 wk postpartum). Multicompartmental modeling was used to assess the rates of bone calcium turnover in relation to calcium intakes and circulating concentrations of parathyroid hormone (PTH), insulin-like growth factor 1, and 1,25-dihydroxyvitamin D. RESULTS: Rates of bone calcium deposition increased significantly from EP to LP (P = 0.001) and were significantly associated with serum PTH during LP (P < or = 0.01). Rates of bone calcium resorption were also higher during LP and EL than during EP (P < or = 0.01) and were associated with both PTH (P < or = 0.01) and IGF-1 (P < or = 0.05) during LP but not during EL. Net balance in bone calcium turnover was positively associated with dietary calcium during EP (P < or = 0.01), LP (P < or = 0.01), and EL (P < or = 0.01). The mean (+/-SD) calcium intake was 463 +/- 182 mg/d and, in combination with insulin-like growth factor 1, explained 68-94% of the variability in net bone calcium balance during pregnancy and lactation. CONCLUSIONS: Net deficits in bone calcium balance occurred during pregnancy and lactation. Increased dietary calcium intake was associated with improved calcium balance; therefore, greater calcium intakes may minimize bone loss across pregnancy and lactation in women with habitual intakes of <500 mg calcium/d.

Early (in uterus and infant) exposure to mercury and lead.

Mercury and lead are toxic metals widely spread in the environment with bio-accumulative features that raises public health concerns. Both metals are equally dispersed in the human food chain but exposure and risk of toxicity during early human development are modulated by the diet and nutritional status. Understanding how Hg and Pb occur and interact with nutrients is fundamental to establish guidelines for diminishing exposure and the risk of toxicity. The risk of fetal and infant exposure to Hg can be influenced by maternal amalgam filling (inorganic Hg) and fish consumption (monomethyl Hg), whereas the risk of exposure to Pb is complex: maternal absorption depends on nutrient interactions (Ca and P); and maternal body Pb accumulation responds to all factors known to interact with bone and calcium metabolism. Maternal exposure to Hg and Pb is more important during fetal development than during breastfeeding. Moreover, these metals (especially Pb) are frequently higher in infant formulas which do not carry the nutritional and psychological advantages and protection of breastfeeding. Infant's reference dose is lower for Hg than for Pb, but risk of Pb contamination for fetuses and infant (breast- or formula-fed) is higher and lasts longer than Hg. Breastfeeding is essential to complete infant development. Interruption or suppression of breast-feeding with cow's milk-based formulas is not an option to environmental pollution.

Effect of the period of resting in elite judo athletes: hematological indices and copper/ zinc-dependent antioxidant capacity.

The purpose of this study was to evaluate the effect of the resting period on hematological and copper-zinc-dependent antioxidant indices in Brazilian elite judo athletes (n = 7). Venous blood samples were collected after 24-h and 5-d periods of resting following a competition, with an interval of 30 d between collections. Two months prior to and during the study, each athlete received an individualized adequate diet. Body composition was determined at both study periods. The following were analyzed: in whole blood, hemoglobin, hematocrit, red cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width, and white cell count; in plasma, zinc, copper, iron, ceruloplasmin, and total iron-binding capacity; in erythrocytes, metallothionein, copper/zinc superoxide dismutase, and osmotic fragility. Dietary intake and body composition did not affect the biochemical measurements. A significant reduction in ceruloplasmin and superoxide dismutase activity was found after 5 d compared to 24 h of resting. A significant correlation between erythrocyte metallothionein and red cell distribution width was observed after 24 h of resting (r = -0.83, p = 0.02), whereas positive correlations of metallothionein with hemoglobin, red cell count, and mean corpuscular hemoglobin concentration were observed after 5 d of resting (r >/= 0.76, p

Zinc absorption and kinetics during pregnancy and lactation in Brazilian women.

BACKGROUND: Adjustments in zinc absorption and endogenous excretion maintain zinc homeostasis in nonpregnant adults fed low-zinc diets. The effects on zinc homeostasis of a low zinc intake during pregnancy and lactation have not been described in a longitudinal study. OBJECTIVE: We examined longitudinal changes in fractional zinc absorption (FZA) and zinc kinetics in 10 healthy Brazilian women who habitually consumed a marginal zinc diet ( approximately 9 mg Zn/d). DESIGN: Zinc status was measured at 10-12 (early pregnancy; EP) and 34-36 (late pregnancy; LP) wk of pregnancy and at 7-8 wk after delivery (early lactation; EL). Zinc kinetics and FZA were studied by using stable isotopic tracers. RESULTS: Zinc intake averaged 9 +/- 3 mg/d throughout the study. FZA increased from 29 +/- 6% at EP to 43 +/- 10% at LP and to 39 +/- 13% at EL (P < 0.05). FZA was inversely related to plasma zinc at EL (r = -0.73, P = 0.02) and LP (r = -0.72, P = 0.07). Plasma zinc mass was 23% greater at LP than at EP or EL (P < 0.05). The amount of zinc (mg/d) that fluxed between plasma and the most-rapidly-turning-over extravascular pool was 53% greater at LP than at EP or EL (P < 0.05). The zinc flux between plasma and the less-rapidly-turning-over zinc pool at EL was 27% greater than that at EP or LP, but this difference was not significant. CONCLUSIONS: FZA increased significantly in women with marginal zinc intakes during pregnancy and lactation; the increase was higher in women with low plasma zinc. Plasma zinc was distributed into a different exchangeable pool at LP than at EL.

Contribution of chlorogenic acids to the iron-reducing activity of coffee beverages.

The iron-reducing activity of coffee beverages was determined by the ferric reducing antioxidant power (FRAP) assay. The influence on FRAP due to the degree of roasting (light, medium, and dark), species (Coffea arabica and Coffea robusta), and caffeine content (regular and decaffeinated) was investigated using ground and soluble coffee samples. The concentration of specific chlorogenic acids and caffeine in the beverages was determined by high-performance liquid chromatography and related to FRAP using Pearson correlation coefficients. All measurements were expressed per unit of soluble solids. Beverages prepared with ground coffee had, on average, 27% higher FRAP values than those prepared with soluble coffee (p < 0.05). In the former beverages, FRAP of C. robusta samples was significantly higher (on average, 50.3%) when compared to that of C. arabica samples, and FRAP values decreased with increasing degree of roasting (p < 0.05). A strong correlation (r > 0.91) was found between FRAP and the total content of chlorogenic acids, particularly that of the caffeoylquinic acid isomers. The iron-reducing activity of coffee beverages was not influenced by caffeine.

Bone mass is recovered from lactation to postweaning in adolescent mothers with low calcium intakes.

BACKGROUND: Adolescent mothers may be at increased risk of irreversible bone loss during pregnancy and lactation, particularly when calcium intake is low. OBJECTIVE: Longitudinal changes in bone mass from lactation to postweaning were evaluated in 10 adolescent mothers aged 15-18 y who habitually consumed <500 mg Ca/d. DESIGN: Total-body bone mineral content (TBBMC), total-body bone mineral density (TBBMD), and lumbar spine bone mineral density (LSBMD) were measured at lactation (6-24 wk postpartum) and after weaning (12-30 mo postpartum). Serum hormones (intact parathyroid hormone, estradiol, and prolactin), serum calcium, and markers of bone turnover [urinary N-telopeptide cross-linking region of type I collagen (NTx) and plasma activity of bone alkaline phosphatase] were measured at lactation. RESULTS: TBBMC, total calcium content, TBBMD, and LSBMD increased from lactation to postweaning (P < 0.01). TBBMD and LSBMD were, respectively, 3.6% and 9.7% lower than predicted at lactation and 0.3% and 4.8% lower than predicted in the postweaning period. The increase in age-matched TBBMD adequacy was correlated with the time after resumption of menses (r = 0.86, P < 0.01). Calcium accretion from lactation to postweaning correlated negatively with estradiol (r = -0.86) and prolactin (r = -0.69) and positively with intact parathyroid hormone (r = 0.72) and NTx (r = 0.84) measured at lactation (P < 0.05). CONCLUSIONS: It appears that adolescent mothers with habitually low calcium intakes recover from lactation-associated bone loss after weaning. The rate of bone accretion, however, may not be sufficient to attain peak bone mass at maturity. Hormones regulating bone turnover during lactation may influence bone recovery in adolescent mothers.