Nadia M.F. Trugo

Effect of Subadequate Maternal Vitamin-A Status on Placental Transfer of Retinol and Beta-Carotene to the Human Fetus

The placental transfer of retinol and beta-carotene was assessed based on maternal serum, cord serum and placental levels at term parturition in women with adequate (n = 15; serum retinol > 20 micrograms/dl) and subadequate (n = 16; serum retinol < or = 20 micrograms/dl) vitamin-A status. There was no difference in retinol and beta-carotene levels in placenta and cord serum between these groups. However, differences in the relation of maternal, placental and cord blood components were observed between women with adequate and subadequate vitamin-A status. In women with subadequate status, circulating fetal retinol levels correlated with placental retinol levels, and maternal serum beta-carotene correlated with placental retinol. Within this group, maternal serum beta-carotene and cord serum retinol correlated significantly in women with serum retinol levels lower than 15 micrograms/dl. These results suggest that beta-carotene may be a precursor of retinol in placenta and that this conversion may depend on the nutritional status of the mother, being particularly effective in a more depleted state.

Nutrient composition of banked human milk in Brazil and influence of processing on zinc distribution in milk fractions.

OBJECTIVE AND METHODS We measured the contents of fat, protein, lactose, calcium, phosphorus, zinc, iron, copper, and vitamin A in processed mature milk samples (individual, n = 60, and pooled, n = 10) from a reference human milk bank in Brazil and assessed the effect of pasteurization followed by freezing on the nutrient composition and the pattern of zinc distribution in fractions (fat, whey, and casein) of milk samples (n = 15). RESULTS Mean nutrient concentrations were within expected ranges in mature milk from healthy women, except fat, which was lower. Interindividual variability of nutrient concentrations was high (coefficient of variation, 21-62%) but reduced overall in pooled samples. Processing of milk samples did not affect the nutrient contents but did cause a significant shift (P < 0.04) in the relative distribution of zinc, with a decrease in the whey fraction and an increase in the fat fraction. CONCLUSIONS Redistribution and possible alterations in the zinc-binding pattern during processing in human milk banks may reduce zinc bioavailability to the infant.

Effect of germination of legume seeds on chemical composition and on protein and energy utilization in rats

Abstract Chemical composition of soybeans, lupin seeds and black beans, and protein utilization and energy digestibility of soybeans and lupin seeds determined in a rat model, were compared before and after a 48-h germination. Black beans had a much higher starch content and lower levels of low-molecular-weight (LMW) sugars than soybeans and lupin seeds. Lupin seeds had about twice as much non-starch polysaccharides than the other legumes and higher insoluble dietary fiber. Soluble dietary fiber represented over one third of total dietary fiber in all legumes. After germination, LMW α-galactosides decreased in all seeds, particularly in lupins. Sucrose levels increased in lupins and black beans but decreased in soybeans. Biological indices were significantly higher in lupin seeds than in soybeans. Germination produced a small increase in protein utilization in both legumes. These results indicate that the main advantage of a 48-h germination of legume seeds is the reduction in the α-galactosides.

Polyunsaturated fatty acids and conjugated linoleic acid isomers in breast milk are associated with plasma non-esterified and erythrocyte membrane fatty acid composition in lactating women

Maternal adipose tissue is a major contributor to breast milk long-chain fatty acids, probably through the pool of plasma NEFA. The fatty acid composition of the erythrocyte membrane (EM) is a biochemical index of the intake of fatty acids not synthesized endogenously and of PUFA and long-chain PUFA fatty acid status. The present study investigated the associations between breast milk fatty acid composition and the composition of plasma NEFA and of EM fatty acids with special reference to PUFA, long-chain PUFA and conjugated linoleic acid (CLA). The detailed fatty acid composition of mature breast milk was also reported. Thirty-three healthy, lactating Brazilian women donated milk samples; of these, twenty-four also donated blood samples in an observational cross-sectional study. Breast milk fatty acid composition presented several associations with NEFA and EM composition, which explained most (> or =50 %) of the variability of selected milk PUFA, long-chain PUFA and CLA. Milk CLA was associated with fatty acids that are markers of dairy fat intake in the diet, NEFA and EM. In general, breast milk n-3 fatty acids and CLA, but not n-6 fatty acids, were associated with EM composition, whereas both the n-6 and n-3 fatty acids and CLA in milk were associated with NEFA composition, possibly owing to its role as a direct source of fatty acids for breast milk. These findings emphasize the contribution of the NEFA pool derived from the adipose tissue to the long-chain fatty acid composition of breast milk.

Calcium homeostasis during pregnancy and lactation in primiparous and multiparous women with sub-adequate calcium intakes

Abstract Low calcium intake and parity may be factors affecting calcium homeostasis during pregnancy and lactation. In this study, changes of urinary indices related to bone and renal adjustments of calcium homeostasis were measured in each trimester of pregnancy and in the lactation period, in primiparous (n=35) and multiparous (n=25) women with habitual calcium intakes about half the RDA for this nutrient, in comparison to neverpregnant (control) women (n=23) with similar calcium intakes. Calcium and phosphorous urinary excretion did not change during pregnancy but decreased in the lactation period, similarly in primiparas and mutiparas (p

Cobalamin and cobalamin-binding capacity in human milk

Abstract Information on variability of cobalamin and its binding protein concentrations in human milk is scarce. We investigated their relationship and longitudinal changes up to the third month of lactation, and their inter and intraindividual variability within the day, between breasts and within the feed in samples from nine healthy lactating women. Cobalamin and its binding protein, cobalophin, expressed as cobalamin-binding capacity, presented higher correlations in colostrum and transition milk (r=0.621 and 0.842, respectively) than in other periods of lactation (r

Evidence of inadequate docosahexaenoic acid status in Brazilian pregnant and lactating women

Recently published data concerning dietary intake of fat and food sources of (n-3) long-chain polyunsaturated fatty acids (LCPUFA) in Brazil are reviewed together with data on biochemical indices of PUFA status during pregnancy and lactation and PUFA composition of breast milk in Brazilian adolescents and adults. Potential inadequacies of docosahexaenoic acid (DHA) status among Brazilian pregnant and lactating women have not yet been thoroughly evaluated. The data reviewed show that dietary intake of food sources of n-3 LCPUFA is low and possibly deficient in Brazil, and that biochemical indices of maternal DHA status and breast milk DHA content are low compared to the international literature. These data indicate inadequate DHA status among Brazilian women during pregnancy and lactation, but this evidence needs confirmation through comprehensive and specific population-based studies.

Effect of iron supplementation during lactation on human milk composition

Abstract There are no reports of studies specifically designed to test the effect of maternal iron supplementation on human milk composition. The purpose of this study was to evaluate the effect of moderate (40 mg Fe/day as FeSO 4 ) iron supplementation of nursing women for 3 months after delivery (non-supplemented, n=14: supplemented, n=14) on levels of iron, lactoferrin, total iron-ligands, and zinc in milk. Iron supplementation did not alter significantly iron and zinc levels in milk and the low iron to lactoferrin ratio was maintained, thus preserving the important functions of lactoferrin for the infant organism. However, iron supplementation increased total iron ligands in milk as measured by the total iron-binding capacity and increased the proportion of lactoferrin in total protein secreted. Also, lactoferrin levels tended (P = 0.059) to be higher in milk of the supplemented women. Our results suggest that the increase in total iron ligands and in the proportion of lactoferrin in total protein in milk after iron supplementation may be a response of the mammary gland to a higher plasma transferrin saturation. ( J. Nutr. Biochem. 5:331–337, 1994 .)

Essential and long-chain polyunsaturated fatty acid status and fatty acid composition of breast milk of lactating adolescents.

The aims of the present study were to evaluate essential fatty acids (EFA) and long-chain PUFA (LCPUFA) status in lactating adolescents and its association with breast milk composition. Healthy nursing adolescents from Rio de Janeiro, Brazil (n 30; 14-19 years; 30-120 d postpartum), exclusively or predominantly breast-feeding, participated in this study. Breast milk and blood samples were collected after overnight fasting. Fatty acid composition of breast milk, erythrocyte membrane (EM) and plasma NEFA were determined by GC. Indices of fatty acid status (mean melting point (MMP); EFA status index; DHA status indices, 22 : 5n-6:22 : 4n-6 and 22 : 6n-3:22 : 5n-6 ratios) were calculated from EM fatty acid composition. Dietary intake of n-3 fatty acids was low when compared with current recommendations for lactating women. MMP was associated with indices of DHA status, some individual fatty acids in EM and years post-menarche and weeks postpartum, suggesting the use of erythrocyte MMP as a possible comprehensive biochemical marker of LCPUFA status in this physiological condition. The DHA status of lactating adolescents and their milk DHA concentrations were similar to the values of Brazilian lactating adults, but lower compared with the values of lactating adults from other countries. Therefore, these lactating adolescents were apparently not disadvantaged, as compared with the Brazilian adults, when EM and breast milk fatty acid composition were considered. In general, PUFA in milk from adolescents presented few associations with their concentrations in plasma NEFA and with maternal status. However, milk DHA was associated with maternal LCPUFA and DHA states.

Bioavailability of iron, zinc, folate, and vitamin C in the IRIS multi-micronutrient supplement: effect of combination with a milk-based cornstarch porridge.

The effect of combining a multi-micronutrient supplement with a milk-based cornstarch porridge on the bioavailability of iron, zinc, folate, and vitamin C was evaluated using the plasma curve response over time (8 hours) in healthy women. Three tests were carried out in a crossover design: S (multi-micronutrient supplement), MS (multi-micronutrient supplement plus test meal), and M (test meal). Relative bioavailability was determined as the percent ratio of the area under the curve (AUC) in MS corrected by M, and AUC in S. Compared to S, AUC in MS was smaller for iron (p < .05), for zinc (p < .01), and for folate (p < .05), but not different for vitamin C. Relative bioavailability was lower (p < .05) than 100% for iron (80%), zinc (70%), and folate (85%). The decrease in bioavailability of these nutrients when the multi-micronutrient supplement is combined with a milk-based cornstarch porridge is small. Therefore, the tested meal is a suitable vehicle for the multi-micronutrient supplement.