Selenium status of New Zealand infants fed either a selenium supplemented or a standard formula

Objective: New Zealand soils are deficient in the essential micronutrient, selenium. New Zealand infants have low selenium levels at birth and experience a further decline if fed cows milk based formula. This study examined the selenium status of infants fed with a new commercially available selenium supplemented formula.
Methodology Forty-four newborn infants, whose mothers wished to formula feed, were randomized in an open controlled trial to be fed a commercially available selenium supplemented cows milk formula (containing 17 μg Se/L) or an unsupplemented formula (containing 4.6 μg Se/L). Cord, 1 and 3 month blood samples were obtained for selenium status (plasma and red cell selenium and glutathione peroxidase) and thyroid function.
Results Mean plasma selenium and glutathione peroxidase values were significantly higher in supplemented than unsupplemented infants at 1 month (unpaired t -tests; P <0.0001 and P = 0.001 respectively) and 3 months ( P <0.0001 and P = 0.0005). Analysis within treatment groups between time points (paired t -tests) showed that selenium supplementation prevented the fall in plasma selenium from birth to 1 month seen in unsupplemented infants and was associated with a rise in levels between 1 and 3 months ( P = 0.002).
Conclusions Supplementing cows milk formula with selenium to replicate the levels found in breast milk is nutritionally sound. Feeding from a few days of age with a formula containing 17 μg Se/L in infants with low selenium status at birth is sufficient to cause a rise to 80% of adult levels at 3 months of age.     

Zinc and iron adequacy and relative importance of zinc/iron storage and intakes among breastfed infants

Neonatal nutrient storage and supplies from breast milk contribute to nutrient status and growth of infants during their early life. This study investigated the adequacy of zinc and iron intakes among breastfed infants during the first 4 months and determined the relative importance of zinc/iron storage versus nutrient intakes with infant's biochemical status and growth. A longitudinal study followed lactating women and their breastfed infants from birth to 4 months postpartum. Cord zinc and ferritin concentrations, as indicators of nutrient storages, were determined. Zinc and iron intakes from breast milk were determined by measurement of breast milk volume together with milk zinc and iron concentrations at 2 and 4 months postpartum. Inadequacy of nutrient intakes was determined using average requirement (AR) which were 1.6 and 0.24 mg/day for zinc and iron respectively. Infant's serum zinc and ferritin were determined at 4 months of age. The data were collected from 64 and 56 participants at 2 months and 4 months postpartum. Inadequate zinc intake was found in 14.5 and 40% of infants at 2 and 4 months old, respectively. The prevalence of biochemical zinc and iron deficiency in infants were 76 and 11%, respectively. Iron endowment was significantly associated with serum ferritin at 4 months. The cumulative zinc intake was positively associated with weight gain and weight-for-length Z-score, but not length. This study provides quantitative data on zinc and iron intakes, and demonstrates the relative importance of nutrient storage versus intakes on biochemical status and growth of breastfed infants.     

Selenium Supplementation in X-linked Muscular Dystrophy

ABSTRACT. The selenium concentrations in serum and erythrocytes and the erythrocyte glutathione peroxidase activity were determined in 15 boys with the Duchenne type and in 5 boys with the Becker type of X-linked muscular dystrophy before and during long-term selenium and α-tocopherol supplementation and compared with values in unsupplemented controls. The purpose of the treatment was to improve the muscular strength. Twelve of the 20 patients had pretreatment levels of selenium in serum that were within the 95 % confidence limit of the unsupplemented control children. The values in 2 patients, both with the Duchenne type of muscular dystrophy, fell below this level. Selenium supplementation in a daily dose of 6 μg/kg/day for 6 months caused a substantial rise in both serum and erythrocyte selenium, suggesting suboptimal pretreatment body contents of selenium. The greatest increases in both serum and erythrocyte selenium were observed in subjects with initially low selenium levels. Only in 4 of the 20 patients did the selenium supplementation result in a significant rise in erythrocyte glutathione peroxidase activity. As no sure improvement was noted in muscular strength during this treatment period, the Se dose was increased to 20 μg/kg/day. This resulted in a further rise in both serum and erythrocyte selenium, but not in erythrocyte glutathione peroxidase activity.     

Selenium in Plasma and Erythrocytes in Patients with Down's Syndrome and Healthy Controls

ABSTRACT. The mean plasma selenium concentration (P-Se) in 65 patients with Down's syndrome (DS) did not differ from that in 90 healthy controls. The concentration of selenium in the erythrocytes (E-Se) was higher in DS patients than in controls ( p <0.001). P-Se and E-Se increased progressively with age through childhood in both DS children and controls. The former children, however, started out with higher levels of E-Se and reached adult concentrations earlier (at 7-17 years) than controls (18 years). Adult DS patients and controls did not differ in their mean P-Se or E-Se concentration. There was a significant correlation between P-Se and E-Se both in DS patients and in controls. In DS patients each of these two variables was significantly correlated to glutathione peroxidase (GSH-Px) activity in erythrocytes. A sex difference in the DS children, but not in the controls, was observed with regard to P-Se and E-Se levels, these being higher in DS girls during childhood (0-17 years). This was in accordance with an earlier finding of higher GSH-Px activity in DS girls than in DS boys.     

Iodine status of breastfed infants and their mothers' breast milk iodine concentration

Iodine is an essential nutrient for growth and development during infancy. Data on iodine status of exclusively (EBF) and partially breastfed (PBF) infants as well as breast milk iodine concentration (BMIC) are scarce. We aimed to assess (a) infant iodine nutrition at the age of 5.5 months by measuring urinary iodine concentration (UIC) in EBF (n = 32) and PBF (n = 28) infants and (b) mothers' breast milk iodine concentration (n = 57). Sixty mother–infant pairs from three primary health care centres in Reykjavik and vicinities provided urine and breast milk samples for iodine analysis and information on mothers' habitual diet. The mother–infant pairs were participants of the IceAge2 study, which focuses on factors contributing to infant growth and development, including body composition and breast‐milk energy content. The median (25th–75th percentiles) UIC was 152 (79–239) μg/L, with no significant difference between EBF and PBF infants. The estimated median iodine intake ranged from 52 to 86 μg/day, based on urinary data (assuming an average urine volume of 300–500 ml/day and UIC from the present study). The median (25th–75th percentiles) BMIC was 84 (48–114) μg/L. It is difficult to conclude whether iodine status is adequate in the present study, as no ranges for median UIC reflecting optimal iodine nutrition exist for infants. However, the results add important information to the relatively sparse literature on UIC, BMIC, and iodine intake of breastfed infants.     

Increased Plasma and Erythrocyte Selenium Concentrations but Decreased Erythrocyte Glutathione Peroxidase Activity after Selenium Supplementation in Children with Down Syndrome

ABSTRACT. An investigation was made of the activity of glutathione peroxidase (GSH-Px) in erythrocytes and the levels of selenium in plasma and erythrocytes before, during and after selenium supplementation in children with Down syndrome (DS). This subject is of interest since it has been suggested that selenium supplementation could enhance the GSH-Px activity in erythrocytes, probably leading to unproved protection against oxygen radicals, which might cause damage by lipid peroxidation, especially in the brain. Forty-eight children with DS were treated with selenium-rich yeast tablets (10 μg/kg body weight/day) for 6 months. The supplementation was well tolerated and no side effects were observed. Selenium supplementation resulted in increased concentrations of selenium both in plasma and erythrocytes, but decreased GSH-Px-activity in erythrocytes. Plasma and erythrocyte selenium levels had almost regained the initial values 12 months after termination of the supplementation. Erythrocyte GSH-Px activity, on the other hand, remained reduced and did not return to the presupplementation levels. Until we gain more knowledge about the biological functions of selenium in man and the role of oxygen metabolism in the development of presenile dementia in DS, universal selenium supplementation in DS patients cannot be recommended.     

Plasma lipids and apolipoproteins in breastfed and formula-fed Swedish infants

This study was carried out to compare plasma lipid pattern in breastfed and formula-fed infants and the effects of exchanging breast milk for formula and of introducing weaning foods. Healthy infants, exclusively breastfed at least until 3 mo, were at this age randomly assigned to infant formulas with similar fat composition. Formula was gradually introduced when breastfeeding was discontinued. One group continued to breastfeed beyond 6 mo of age. All infants received the same weaning foods and were studied between 3 and 12 mo of age. Decreased plasma concentrations of total and low-density lipoprotein cholesterol (TC, LDL-C), apolipoprotein B (apo B) and A1 (p < 0.001), and of high-density lipoprotein cholesterol (p < 0.05) were found when breast milk was exchanged for formula before 6 mo. At this age plasma TC, LDL-C and apo B were lower in formula-fed than in breastfed infants (p < 0.001). These plasma lipids then increased (p < 0.01) when the intake of formula decreased and that of weaning foods increased. However, plasma TC and/or LDL-C remained lower at 12 mo in formula-fed than in breastfed infants (p < 0.05). Our results indicate that the plasma lipid profile of infants is highly responsive to the dietary nutrient intake, as indicated by the decrease in plasma lipids and apolipoproteins when breast milk was exchanged for formula and by the increase in these concentrations when the intake of weaning foods gradually increased.     

Longitudinal Study of the Selenium Content in Human Breast Milk in Belgium

ABSTRACT. The selenium content of expressed human milk obtained at different stages of lactation from 32 lactating mothers was measured by hydride generation atomic absorption spectrometry after previous wet acid digestion. The highest selenium level was found in colostrum (14.8 ng/g; wet weight), subsequently the content declined and plateaued off after one month (9.4 ng/g; wet weight). The daily selenium intake for Belgian infants of 3 months of age was found to be 7.1 μg (girls) and 8.1 μg (boys), which is lower than the values obtained in most other countries and lower than the recommended safe and adequate daily intake of 10 to 40 μg/day for the same age group.     

Studies on Perceived Breast Milk Insufficiency: III. Consequences for Breast Milk Consumption and Growth

ABSTRACT. Fifty-one mother–infant pairs were followed prospectively during the period 3 days to 18 months after delivery. In total 54.9% of the mothers experienced transient lactation crises, emanating mostly from a perception of breast milk insufficiency. Within the crisis group no significant difference in the infants' intake of breast milk during the crises compared with control measurements 1 week later was found. Nor had the crises any immediate impact on growth of the infants. A comparison between the crisis and the non-crisis group, revealed that the breast milk consumption in the crisis group was throughout lower with significant differences at 3 and 5 months. The infants in the crisis group also had a significantly lower weight at 2, 3, 4 and 9 months and were significantly thinner for their height at 1–6 months and at 9 months, although both groups were above the NCHS mean. We conclude that even if the infants in the crisis group had a lower consumption and a slower growth development, the differences were comparatively small. Furthermore, evidence was provided that the breast milk insufficiency occasionally perceived as acute by the mothers was in most cases not real.     

Selenium status of preterm infants: the effect of postnatal age and method of feeding

Indicators of selenium (Se) status were measured in a longitudinal study of 63 preterm and 46 term infants. Se levels in both groups were similar in the first few days of life. Preterm infants fed parenteral nutrition (PN) for several weeks developed very low plasma Se levels (<10/μg/l). In those receiving either breast milk or formula in conjunction with PN, plasma Se also declined over the first 6 weeks. In the breastfed term infants plasma levels increased by 50%, but there was no increase in the term formula-fed group. In healthy preterm infants who received mainly breast milk, plasma Se concentrations remained constant at newborn levels and were below those of breastfed term infants at 6 weeks. Erythrocyte GSHPx activity did not reflect plasma Se or Se intake. In conclusion, the type of feeding, and hence Se intake, influenced plasma Se concentration in preterm infants. Provision of enteral feeding in conjunction with PN was unable to prevent a decline in plasma Se and at 6 weeks levels were well below those of the reference breastfed term infants.     

Plasma total homocysteine increases from day 20 to 40 in breastfed but not formula-fed low-birthweight infants

Homocysteine is an intermediate in the folate cycle and methionine metabolism. This study investigated whether formula-fed infants have different plasma total homocysteine to their breastfed counterparts, and during what period any difference developed. Plasma total homocysteine was determined in 53 formula-fed and 15 breastfed healthy low-birthweight babies (< or = 2500 g) around days 10, 20 and 40. Total homocysteine was also measured in human milk. Mean +/- SD plasma total homocysteine levels (micromol l(-1)) at days 10, 20 and 40 were 6.4 +/- 2.6, 6.7 +/- 2.4 and 9.1 +/- 2.4 (breastfed), and 7.5 +/- 3.2, 7.3 +/- 2.1 and 7.4 +/- 1.6 (formula-fed). Homocysteine of breastfed babies at day 40 was higher than that of breastfed babies at day 20 (p < 0.0001), and that of formula-fed counterparts at day 40 (p = 0.002). Homocysteine correlated negatively with formula (day 10) and breast milk (day 40) volume intakes. Median (range) homocysteine in 12 mature human milk samples was 0.30 (not detectable to 0.7) micromol l(-1). Conclusion: Increasing plasma total homocysteine in breastfed babies to higher levels compared with formula-fed babies may be caused by a gradually developing suboptimal B-vitamin status in lactating women.     

Intestinal microflora in breastfed colicky and non-colicky infants

BACKGROUND: Infantile colics are a common problem in the first months of life. During this period, a process of intestinal colonization rapidly occurs. A difference in the gut microflora could play an important role in the pathogenesis of colics, changing the metabolism of carbohydrates and fatty acids. Actually, in the literature, only few data have been collected about this topic. In this study, we evaluated intestinal microflora in breastfed colicky and non-colicky infants. METHODS: Seventy-one breastfed infants, aged 3.2 +/- 0.6 wk, free from episodes of gastroenteritis and without previous assumption of antibiotic and probiotic drugs, were enrolled in the study. They were divided into two groups: colicky (42 cases) and non-colicky (29 cases), according to Wessel's criteria. Stool samples were collected, diluted and cultured on several selective media to detect lactobacilli, clostridia, gram-negative anaerobes and Enterobacteriaceae. Statistical analysis was performed using Student's t-test, chi2 test and a non-parametric test (Mann-Whitney U-test). RESULTS: Differences in gut microflora were found among colicky and non-colicky infants: colicky infants were less frequently colonized by Lactobacillus spp., and more frequently by anaerobic gram-negative bacteria. CONCLUSION: Our study indicates that colicky infants have different patterns of gut microflora. Further studies are required to understand whether gut microflora is the primary cause of colics or its consequence.     

Differences in the pattern of milk intake between breast and bottle fed infants

Two hundred and nine 6-day-old healthy term infants were test weighed either during bottle feeding (n = 77) or breast feeding (n = 132). Cross-sectional data collection avoided repeated interruptions of individual feeds. Bottle fed infants (fed ad libitum) and breast fed infants consumed a similar feed volume (respectively, 67 ± 2 ml versus 75 ±6 ml, mean ±S.E.M.) over a similar period of time (mean 25 min); yet the pattern of milk flow during feeding was significantly different in the two groups. In bottle fed infants, there was a linear pattern of milk intake over the first 10 min of feeding, by which time 81% of the feed has been consumed, contrasting with a biphasic intake pattern in breast fed infants in whom a total 84% of the feed was consumed either in the first 4 min or between 15 and 19 min after the start of the feed. It is speculated that these differences in the pattern of milk intake could influence the physiological responses to feeding and might account for differences between breast and bottle fed infants in gut hormonal responses to milk feeds.     

Accuracy and precision of test weighing to assess milk intake in newborn infants

BACKGROUND: Test weighing is commonly used to estimate milk intake in newborn infants. OBJECTIVE: To assess the accuracy and precision of test weighing in clinical practice. METHODS: Infants fed by bottle, cup, or nasogastric tube were weighed before and immediately after feeding by a blinded investigator. Actual milk intake was determined by reading the millilitre scale of the milk container before and after feeding. The accuracy and precision of test weighing was assessed by examining the frequency distribution of the difference between weight change and actual milk intake. RESULTS: Ninety four infants completed the study. The mean difference between weight change and actual milk intake was 1.3 ml, indicating good accuracy. The precision of test weighing, however, was poor: 95% of differences between weight change and actual milk intake ranged from -12.4 to 15 ml. The maximum difference was 30 ml. Imprecision was not influenced by the presence of monitor or oxygen saturation wires, intravenous lines, or vomiting of the infant. CONCLUSIONS: Test weighing is an imprecise method for assessing milk intake in young infants. This is probably because infant weighing scales are not sensitive enough to pick up small changes in an infant's weight after feeding. Because of its unreliability, test weighing should not be used in clinical practice.     

Gastric emptying in pre-term infants: the effect of breast milk fortifier

Failure of adequate gastric emptying frequently prevents successful, early enteral nutrition in the preterm infant. The effect on gastric emptying of adding breast milk fortifier is unknown, but clinical experience suggests that it is less well tolerated by some infants. We therefore compared gastric-emptying rates of breast milk and fortified breast milk within pre-term infants, using a previously described ultrasonic technique. Eleven infants were studied on 22 occasions. Median (range) gestation of the group was 28 weeks (25-31) with birth weight 1090 g (714-1360). The human milk fortifier FM-85 (Nestlé, Vevey, Switzerland) was used in all infants. Half-emptying time for unfortified breast milk was less than half that for fortified breast milk. Mean (±SEM) half emptying times were 21 min (±3.6) and 48 min (±4.0), respectively. Breast milk emptied faster than fortified breast milk in 10 out of 11 patients. These data demonstrate that the addition of human milk fortifier can significantly slow gastric emptying. This has important implications for the management of infants who have feed intolerance.     

母乳强化剂在母乳喂养早产儿中的应用

目的 通过前瞻性对照试验评价强化母乳对住院早产儿短期生长、营养状况的影响.方法 出生胎龄≤34周、出生体重≤1 800 g的24例早产儿分为强化母乳组(试验组,11例)和早产配方奶组(对照组,13例).试验组早产儿的母乳喂养量均超过总奶量的50%,当喂养量达到100 ml/(kg·d)时开始添加FM85母乳强化剂,不够的奶量用早产配方奶补足;对照组全部用早产配方奶喂养.对两组的生长速度、血生化指标、肠内外营养情况、合并症进行比较.结果 试验组出生胎龄(30.6±2.9)周,平均出生体重(1 80±286)g;对照组出生胎龄(31.6±1.9)周,平均出生体重(1 436±201)g.试验组在住院期间,平均母乳量占总喂养量81.6%,母乳强化剂在平均胎龄34.1周、生后24.6 d时开始添加.试验组与对照组的体重[18.9 vs 7.1 g/(kg·d),P=0.364]、身长(1.16 vs .00 cm/周,P=0.308)、头围(0.79 vs .61 cm/周,P=0.057)的增长速度近似,差异无统计学意义.出院时两组血尿素氮水平相似,试验组血清白蛋白、前白蛋白、血磷水平较对照组低,血清碱性磷酸酶和血钙值较对照组高,喂养不耐受、坏死性小肠结肠炎、院内感染的发生率无统计学意义.结论 强化母乳喂养与早产配方奶喂养的早产儿在住院期间的生长速度相似.     

Quantifying breast milk intake by term and preterm infants for input into paediatric physiologically based pharmacokinetic models

Despite the many benefits of breast milk, mothers taking medication are often uncertain about the risks of drug exposure to their infants and decide not to breastfeed. Physiologically based pharmacokinetic models can contribute to drug‐in‐milk safety assessments by predicting the infant exposure and subsequently, risk for toxic effects that would result from continuous breastfeeding. This review aimed to quantify breast milk intake feeding parameters in term and preterm infants using literature data for input into paediatric physiologically based pharmacokinetic models designed for drug‐in‐milk risk assessment. Ovid MEDLINE and Embase were searched up to July 2, 2019. Key study reference lists and grey literature were reviewed. Title, abstract and full text were screened in nonduplicate. Daily weight‐normalized human milk intake (WHMI) and feeding frequency by age were extracted. The review process retrieved 52 studies. A nonlinear regression equation was constructed to describe the WHMI of exclusively breastfed term infants from birth to 1 year of age. In all cases, preterm infants fed with similar feeding parameters to term infants on a weight‐normalized basis. Maximum WHMI was 152.6 ml/kg/day at 19.7 days, and weighted mean feeding frequency was 7.7 feeds/day. Existing methods for approximating breast milk intake were refined by using a comprehensive set of literature data to describe WHMI and feeding frequency. Milk feeding parameters were quantified for preterm infants, a vulnerable population at risk for high drug exposure and toxic effects. A high‐risk period of exposure at 2–4 weeks of age was identified and can inform future drug‐in‐milk risk assessments.     

Concentrations of alpha‐ and gamma‐tocopherols in human breast milk during the first months of lactation and in infant formulas

The aim of this study was to determine the concentrations of alpha‐ and gamma‐tocopherols in human breast milk samples from different periods of lactation and to compare them with tocopherol content in commercially available formulas for infants at corresponding ages. The study included 93 breast milk samples obtained on the 2nd (colostrum, n = 17), 14th (n = 30), 30th (n = 27) and 90th day of lactation (n = 19), along with 90 samples of commercially available initial and follow‐on infant formulas. Concentrations of tocopherols were determined using normal‐phase high‐performance liquid chromatography. Depending on the stage of lactation, human breast milk contained 2.07–9.99 mg L^?1 of alpha‐tocopherol and 0.22–0.60 mg L^?1 of gamma‐tocopherol. Breast milk concentrations of alpha‐tocopherol decreased with the time of lactation, while significant differences in gamma‐tocopherol concentration were observed only between the 14th and 30th day of lactation. There was no significant correlation between the dietary intake of vitamin E and its estimated breast milk concentration, also in women who declared vitamin supplementation. Compared with colostrum, infant formulas were characterised by significantly lower concentrations of alpha‐tocopherol and vitamin E. This finding indicates the need of additional vitamin E supplementation of bottle‐fed infants during the initial 2–3 days of life.     

Superoxide dismutase and glutathione peroxidase in polymorphonuclear leucocytes

Superoxide dismutase (SOD) and glutathione peroxidase (GPX) protect aerobic organisms against the toxic superoxide anion and hydrogen peroxide, which are generated during phagocytosis by polymorphonuclear leucocytes (PMNs). PMNs of children with bacterial infections and with infectious hepatitis contained significantly elevated SOD activity, whereas GPX activity remained in the normal range. In contrast, PMNs of children with viral infections and rheumatoid arthritis exhibited a decreased SOD activity, while GPX activity was again unchanged. The children's age, sex or treatment did not effect the enzyme activities in PMNs. Since SOD generates bactericidal hydrogen peroxide and regulates the release of the toxic superoxide radical into the surrounding tissues, this study may add new understanding to the pathophysiological aspects of acute and chronic inflammatory processes.This study contains data of a thesis submitted as part of the requirement for an M.D.