Selenium status of exclusively breast-fed infants as influenced by maternal organic or inorganic selenium supplementation

A longitudinal dietary Se supplementation study on lactating mothers was performed to determine the possibilities of improving the Se status of exclusively breast-fed infants. A total of 200 mothers randomized into three groups received either no Se supplements, 100 micrograms of selenite, or 100 micrograms of yeast-Se daily. Maternal and infant serum Se concentrations showed a linear correlation during exclusive breast-feeding. Yeast-Se in the dose administered was safe and more effective than selenite in increasing the Se concentrations of maternal serum and milk, and infant serum. The mean estimated daily Se intakes of the infants were 7.7 +/- 2.2, 8.9 +/- 2.2, and 11.5 +/- 4 micrograms, in the control, selenite, and yeast-Se groups respectively. Though the infant Se intakes of the unsupplemented and selenite-supplemented mothers were below the lower limit of the safe and adequate range as set by the US National Research Council, their serum Se concentrations increased steadily over the 6-mo study period. As maternal serum Se also increased by over 50% during the same period the results suggest that a maternal daily intake of 50-75 micrograms is adequate during lactation.     

保健食品中有机硒和无机硒的分析探讨

目的:建立同时测定保健食品中有机硒和无机硒含量的方法。方法:用硝酸-高氯酸混合酸体系将样品中的有机硒氧化成无机硒后测定总硒含量,同时用酸提取样品中的无机硒,再通过差减法获得有机硒的含量。结果:经回收实验和实际样品检测,方法的回收率为95.0%~105.6%,RSD为2.5%~4.9%。结论:该方法线性范围宽,相关性好,精密度和准确度好,可操作性强,应用范围广,具有较高的实用价值。     

Selenium in Human Nutrition in New Zealand

New Zealand's soil has a low concentration of selenium (Se), and its residents have a lower Se status than do most other peoples. However, New Zealanders do not suffer from the Se-responsive ills that afflict their farm animals and some people in China. New Zealanders, particularly those in the South Island, may have adapted to their low Se environment by thriftiness in urinary excretion of Se. Low glutathione peroxidase activities in their tissues have not resulted in noticeable damage or changes. The enzyme activity can be raised to a plateau by Se supplements, but there is no evidence that supplementation leads to better health. Since patterns of coronary heart disease, hypertension, and cancer in New Zealand resemble those in other Western countries, no direct link between these diseases and Se level is likely.     

Toxicity of organic and inorganic selenium to mallard ducklings

The toxicity of selenomethionine and sodium selenite to mallard ducklings (Anas platyrhynchos) was measured by feeding each form from hatching to six weeks of age at dietary concentrations of 0, 10, 20, 40, and 80 ppm selenium. At 80 ppm selenium, sodium selenite caused 97.5% mortality by six weeks and selenomethionine caused 100% mortality. At 40 ppm, these two forms of selenium caused 25 and 12.5% mortality. No mortality occurred at 10 or 20 ppm. Diets containing 20, 40, or 80 ppm selenium in both forms caused decreases in food consumption and growth. The only statistically significant effect of 10 ppm selenium was with sodium selenite, which resulted in larger livers than controls. Selenomethionine was more readily stored in the liver than sodium selenite at levels above 10 ppm selenium in the diet. Based on comparisons of residues of selenium in livers of surviving and dead ducklings, concentrations in the liver were not diagnostic of death due to selenium poisoning. Because both forms of selenium resulted in severe reductions in food consumption, selenium-induced starvation may have been related to duckling mortality. It was not clear whether either form of selenium at 10 ppm in the diet resulted in a leveling off of selenium concentrations in the liver within six weeks.     

Deposition of dietary organic and inorganic selenium in rat erythrocyte proteins

The deposition of selenium (Se) in erythrocyte proteins was studied in rats fed Se as sodium selenite, selenocystine, selenomethionine (Se-Met), high Se wheat or selenium-enriched yeast. Ion-exchange chromatography of acid hydrolyzates of selenium-enriched yeast, high Se wheat and intrinsically labeled 75Se wheat indicated that the majority of the Se was present as Se-Met. Gel filtration (Sephadex G-150) of erythrocyte lysates revealed that Se was deposited mainly in two proteins, glutathione peroxidase (GPx) and hemoglobin (Hb). When selenite or selenocystine was the dietary form of Se, the majority of the erythrocyte Se was present with GPx, but when the Se was supplied from either Se-Met, yeast or wheat, it was deposited to a greater extent in Hb than GPx. Injection of 75Se as either Se-Met or selenite gave results consistent with the feeding studies. 75Se-labeled selenite injection resulted in labeling of primarily GPx, but 75Se-Met injection labeled predominantly Hb. Hence, the dietary forms of Se influence the relative distribution of Se between GPx and Hb in erythrocytes, and this may be a factor contributing to the difference between human and animal erythrocytes.     

Selenium and zinc status are suboptimal in a sample of older New Zealand women in a community-based study

The importance of selenium and zinc in the immune functioning of the aged is widely recognized. Seniors in New Zealand are at particularly high risk of low selenium status because of the low selenium soil environment. The zinc status of the New Zealand elderly has never been assessed. In this cross-sectional study, the biochemical selenium, zinc and lipid levels, physical functional capacity and dietary intakes of 103 randomly selected free-living New Zealand women (mean age +/- SD, 75 +/- 3 y) were assessed. Among nonusers of selenium supplements (n = 80), 80% [95% confidence interval (CI): 70; 88%] had plasma selenium levels (0.85 +/- 0.23 micromol/L) below 1.00 micromol/L [ approximately 10% below mean plasma selenium necessary for full expression of glutathione peroxidase (GPx) activity in New Zealand subjects]. Plasma selenium was strongly correlated with GPx: r = 0.56; P < 0.0001. For nonusers of zinc supplements (n = 88), serum zinc concentrations were 12.4 +/- 1.4 micromol/L, with 12% (95% CI: 6; 21%) having levels below the cut-off value (10.7 micromol/L). Estimated mean daily selenium and zinc intakes were 34 +/- 10 microg and 8.7 +/- 2.0 mg, respectively. Subjects in the highest tertile of a functional capacity index had higher biochemical zinc and selenium values than those in the lowest tertile (P < 0.05). The correlation between plasma selenium and GPx indicates that selenium intake in these women is still insufficient for full expression of GPx activity. Lower serum zinc levels also appear to be prevalent. Because a suboptimal trace element status may be more common among those with a poor physical functioning, promotion of the consumption of nutrient dense foods or supplements to improve selenium and zinc status of elderly women in New Zealand may be beneficial.     

Growth characteristics and selenium status changes of yeast cells with inorganic and organic selenium supplementation: selenium,a chemopreventive agent

We attempted to determine the level and form of selenium (Se) that yielded the maximum Se status of yeast cells, for their evaluation as a source of Se for chemopreventive action. The influence of various Se concentrations from organic (selenomethionine) and inorganic (sodium selenite) Se compounds on growth pattern and cell viability and the alterations in the antioxidant enzyme system of yeast were evaluated. A continuous decrease in cell and colony-forming units counts was observed with increasing concentrations of Se from either source. Increasing Se status of yeast cells was found with increasing concentrations of Se with both forms, with much greater uptake for organic Se at maximum Se concentrations. A continuous increase in glutathione peroxidase (GSH-Px) activity with increasing Se concentrations in both forms revealed an active Se response in terms of antioxidant activity, with a more pronounced percentage increase with selenomethionine. A highly significant increase in total glutathione was observed with selenomethionine supplementation, compared with sodium selenite. A decreasing trend in reduced glutathione was observed with increasing organic or inorganic Se concentrations. An increasing trend in glutathione-S-transferase activity was observed with increasing Se concentrations for both forms. Significantly higher values of glutathione-S-transferase were associated with the organic form at higher Se concentrations. There was normal activity of Se in mammalian cells. The results showed that an organic Se source more greatly enhances the Se status of yeast cells and hence could help in chemoprevention if consumed by the population.     

Risk–taking behaviours in a sample of New Zealand adolescents

Abstract: We surveyed the risk–taking behaviour of students aged 16 years and over in two New Zealand high schools, with a particular focus on road safety, substance use, sexual behaviour and personal safety. The questionnaire was completed by 471 students, a participation rate of 99 per cent. We found that seven out of 10 students who had ridden either a bicycle or motorcycle in the previous 12 months had not always worn a helmet; that 56 per cent had driven a car without a licence; and 23 per cent had been involved in a motor vehicle crash. A lifetime incidence of 63 per cent for cigarette smoking, 34 per cent for marijuana use and 78 per cent for alcohol use was found. Forty per cent of the students reported ever having sexual intercourse. During the previous 12 months, 49 per cent of these had not always used contraceptives and 61 per cent reported not always wearing condoms as protection for sexually transmitted diseases. Twenty–five per cent had physically harmed another person and 10 per cent reported carrying a weapon with the intent of harming someone else. This study shows that adolescents are willing to provide information on risk taking and that they are engaging in high levels of health–harming behaviour. Such information is important for designing health promotion programs to address adolescent risk taking. ( Aust N Z J Public Health 1997; 21: 455–61)     

Selenium and iodine intakes and status in New Zealand and Australia

Most New Zealand soils contain relatively low concentrations of the anionic trace elements F, I and Se. Some areas of Australia also have a history of I deficiency. In view of current interest in establishing nutrient reference intakes for Se and I in New Zealand and Australia, it is timely to review current understanding of the intakes and status of these two elements. In spite of a recent increase in Se status, the status of New Zealanders remains low compared with populations of many other countries and may still be considered marginal, although the clinical consequences of the marginal Se status are unclear. There are no recent reports of blood Se levels in Australia, but earlier reports indicate that they were generally greater than those of New Zealanders. Similarly, the consequences of decreasing I status in Australia and New Zealand are unclear. Mild I deficiency in New Zealand has resulted in enlarged thyroid glands indicating an increased risk of goitre. Currently there is little evidence, however, of any associated clinical disease. Public health recommendations to reduce salt intake, together with the reduction in I content of dairy products, are likely to result in further decreases in the I status of New Zealand and Australian residents. Some action is needed to prevent this decline and it may be necessary to consider other means of fortification than iodized salt. The consequences of possible interactions between Se and I in human nutrition are also unclear and no practical recommendations can be made.     

Serum selenium concentrations and dietary selenium intake of New Zealand children aged 5-14 years

Serum Se concentrations and dietary Se intakes have been determined in relation to age, sex, ethnicity, region and index of deprivation in a nationally representative sample of New Zealand children aged 5-14 years from the 2002 National Children's Nutrition Survey. Dietary intake was assessed from computer-assisted, multiple-pass 24 h diet recall interviews (n 3275). Serum Se concentrations were obtained from a subset of urban-based children (n 1547). Mean (95 % CI) serum Se concentration in children was 0.96 (0.93, 1.00) micromol/l. Males (1.00 micromol/l) had higher serum Se levels than females (0.93 micromol/l; P = 0.027). M?ori children had lower serum Se than Pacific Islands children (P = 0.038) and New Zealand European and Other children (P = 0.005). Children in the Upper North Island (1.06 micromol/l) had higher mean serum Se values than those in the Lower North Island (0.98 micromol/l, P < 0.0005) and South Island (0.79 micromol/l, P < 0.0005), and serum Se in the Lower North Island was higher than that in the South Island (P < 0.0005). Mean dietary Se intake was 36 (34, 37) microg/d. The intakes of children aged 5-6 years (31 microg/d) were lower than those of children aged 7-10 and 11-14 years (35 and 38 microg/d, respectively; P < 0.00 005) and the intakes of 7-10-year-olds were lower than those of 11-14-year-olds (P = 0.002). Serum Se was associated with dietary Se after adjusting for all variables, including region (P = 0.006). The Se status of our children falls in the middle of the international range of serum Se concentrations, but that for children in the South Island is among the lowest values reported and may be a cause for concern.     

Reduction in organochlorine levels in the milk of New Zealand women

In this study, the authors investigated whether measures taken to reduce exposures subsequent to 1988 led to detectable reductions in levels of persistent organochlorine compounds in milk samples of New Zealand women collected in 1998-1999. The procedures and selection criteria used in a 1987-1988 study were replicated. Participants (n = 53) completed a questionnaire and provided a milk sample, which the authors analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyl congeners, and organochlorine pesticides. Levels of most compounds measured in this study declined approximately 70% from their 1987-1988 values. Levels were low, compared with those found in similar studies from other countries. These results provide evidence that exposure of New Zealand women to organochlorine substances has substantially declined, suggesting that policy measures to reduce exposures have been effective.     

Effects of supplementation with high-selenium wheat bread on selenium, glutathione peroxidase and related enzymes in blood components of New Zealand residents

The effects of supplementation with high-Se wheat bread on selenium (Se) concentrations, glutathione peroxidase (EC 1.11.1.9, GSHPx) activities and related enzymes in the prevention of lipid peroxidation were studied. Four New Zealand women were supplemented with 200 micrograms Se daily for 8-13 weeks followed by a post-dosing period of 9-12 weeks. GSHPx activities increased in whole blood, erythrocytes, plasma and platelets of all subjects but increases were considerably less than those of Se concentrations in whole blood, plasma and erythrocytes. During the post-dosing period Se concentrations and GSHPx activities fell to levels which were in most cases somewhat higher than baseline values. Glutathione-S-transferase activities in erythrocytes, plasma and platelets did not change during the study, nor did superoxide dismutase in erythrocytes and platelets, erythrocyte catalase or plasma alpha-tocopherol. Thus Se supplementation of healthy New Zealand subjects increased GSHPx activities but did not produce any adaptive changes in other components of the lipid peroxidation defense mechanisms.     

Selenium intake and serum selenium in Finland: effects of soil fertilization with selenium

Since fall 1984 all agricultural multinutrient fertilizers in Finland have been supplemented with sodium selenate in an attempt to improve the nutritional quality of local foodstuffs known to be exceptionally low in selenium. The intervention has been effective from the growing season 1985 and it has affected practically all domestic agricultural products. From 1984 to 1986 the mean Se concentration of different foods increased. The mean Se intake of the population, calculated on the basis of food consumption statistics and from the data of urinary Se excretion, as well as the average serum Se concentration of both urban and rural people increased also during the same period. Enrichment of fertilizers with sodium selenate seems an efficient and predictable way of increasing the Se concentration of foods and the Se intake of people in low-Se areas.     

Both inorganic and organic selenium supplements can decrease brain monoamine oxidase B enzyme activity in adult rats

It has been observed that the levels of brain monoamine oxidase B (MAO-B) increase during ageing. MAO catalyses the oxidative deamination of neurotransmitters, in which the by-product H2O2 is subsequently generated. Se exists naturally in inorganic and organic forms and is considered to play a key role in antioxidation functioning. The objective of the present study was to investigate two chemical forms of Se compounds for their inhibition effect on rat brain MAO-B. The total antioxidant capacity and lipid peroxidation of rats were also examined. The rats (age 7 weeks) were divided into four groups: the control group, tocopherol group (T group, positive control), selenite group (SE group, representing the inorganic Se group) and seleno-yeast group (SY group, representing the organic Se group). The rats were fed for 11 weeks with normal diets and 12 weeks with test diets. The serum total antioxidant capacity of the SE and SY groups was significantly higher than that in the control and T groups. In rat brains and livers, the lipid peroxidation levels were significantly decreased in the T, SE and SY groups. MAO-B activity showed a significant decrease in the T, SE and SY groups in rat brains but no significant change could be noted in the rat livers. In conclusion, the present study indicates that inorganic or organic Se supplementation can decrease the brain MAO-B enzyme activity in adult rats and can be accomplished by the effect of the Se antioxidation capability.     

Pertussis and influenza immunisation coverage of pregnant women in New Zealand

BackgroundImmunisation is an important public health policy and measuring coverage is imperative to identify gaps and monitor trends. New Zealand (NZ), like many countries, does not routinely publish coverage of immunisations given during pregnancy. Therefore, this study examined pregnancy immunisation coverage of all pregnant NZ women between 2013 and 2018, and what factors affected uptake.MethodsA retrospective cohort study of pregnant women who delivered between 2013 and 2018 was undertaken using administrative datasets. Maternity and immunisation data were linked to determine coverage of pertussis and influenza vaccinations in pregnancy. Generalised estimating equations were used to estimate the odds of receiving a vaccination during pregnancy.ResultsFrom 2013 to 2018 data were available for 323,622 pregnant women, of whom 21.7% received maternal influenza immunisations and 25.7% maternal pertussis immunisations. Coverage for both vaccines increased over time, pertussis increased from 10.2% to 43.6% and influenza from 11.2% to 30.8%. The odds of being vaccinated, with either vaccine, during pregnancy increased with increasing age and decreasing deprivation. Compared to NZ European or Other women, Māori and Pacific women had lower odds of receiving a maternal pertussis (OR:0.55, 95% CI: 0.54, 0.57; OR:0.60, 95% CI: 0.58, 0.62, respectively) and influenza (OR: 0.69, 95% CI: 0.67, 0.71; OR:0.90, 95% CI: 0.87, 0.94, respectively) immunisations during pregnancy. Women were also more likely to be vaccinated against pertussis if they received antenatal care from a General Practitioner or Obstetrician compared to a Midwife. A similar pattern was seen for influenza vaccination.ConclusionGaps in maternal coverage for pertussis and influenza exist and work is needed to reduce immunisation inequities.     

A comparison of methods of assessment of dietary selenium intakes in Otago, New Zealand

The aims of the present study were (1) to compare three methods of assessment of dietary Se intake, i.e. chemical analysis of duplicate diets, diet records and a food-frequency questionnaire (FFQ) designed specifically for Se, and (2) to determine dietary Se intakes of residents of Otago, New Zealand. The FFQ was completed by 110 free-living adults. Diet records (3 d) and duplicate diet collections were carried out by forty-three of these subjects chosen on the basis of low blood Se concentration, and during a period when consumption of the high-Se foods fish, kidney, liver and Brazil nuts was discouraged. Mean Se intakes were similar for duplicate diet analysis (29 (SD 13) micrograms/d) and diet record assessments (28 (SD 15) micrograms/d). Estimates of intakes from the FFQ for the subgroup of forty-three subjects were higher (51 (SD 26) micrograms/d) than those from duplicate diets and diet records. Values from duplicate diet analysis and diet record assessments were strongly correlated (r 0.7, P = 0.0001), but difference plots indicated a lack of agreement between the two methods. Thus, diet record assessment was not adequate for predicting dietary Se intakes of individuals. Significant correlations were found for relationships between Se intake from duplicate diets (microgram/kg body weight per d) and plasma Se, Se intake from diet records (microgram/d and microgram/kg body weight per d) and plasma Se; and Se intake from the FFQ and whole-blood Se. Se intakes from duplicate diets and diet records were similar to those reported previously for New Zealanders, but lower than the recommended intakes in the USA (National Research Council, 1989), Australia (Truswell et al. 1990) and the UK (Department of Health, 1991) and the World Health Organization/Food and Agriculture Organization/International Atomic Energy Agency (1996) normative requirement.     

Serum resistin levels in women taking combined oral contraceptives containing desogestrel or gestodene

Resistin is a hormone secreted by adipose tissue that could be involved in the development of insulin resistance. Previous studies confirmed that endogenous sex steroids may influence serum resistin concentration in women. The aim of our study was to investigate the influence of combined oral contraceptives containing desogestrel or gestodene on circulating levels of resistin. Fifty-three women were enrolled in the study. Thirteen patients received 20 μg ethinylestradiol/150 μg desogestrel, 15 women were treated with 20 μg ethinylestradiol/75 μg gestodene, 11 with 30 μg ethinylestradiol/150 μg desogestrel and 14 with 30 μg ethinylestradiol/75 μg gestodene. Blood samples for estimation of serum resistin and insulin levels were drawn before administration of oral contraceptive and after 6 cycles of therapy. We found that serum resistin level remained unchanged in women receiving ethinylestradiol/desogestrel and was reduced in women treated with formulations containing gestodene. We conclude that ethinylestradiol combined with desogestrel or gestodene is unlikely to induce insulin resistance through resistin pathway.     

Cardiovascular mortality attributable to high blood cholesterol in New Zealand

OBJECTIVE: To estimate mortality attributable to higher-than-optimal blood cholesterol in New Zealand in 1997, and the mortality burden that could be potentially avoided in 2011 if modest reductions in mean population blood cholesterol concentrations were achieved. DESIGN: Comparative risk assessment methodology was used to estimate the attributable and avoidable mortality due to higher-than-optimal total blood cholesterol (> 3.8 mmol/L). Disease outcomes assessed were deaths from ischaemic heart disease (IHD) and ischaemic stroke. RESULTS: Overall, higher-than-optimal blood cholesterol contributed to 4,721 deaths in New Zealand in 1997 (17% of all deaths). This included 4,096 IHD deaths (64%) and 625 ischaemic stroke deaths (38%). Modest reductions in mean population blood cholesterol concentrations (e.g. 0.1 mmol/L) could potentially prevent 300 deaths (261 IHD and 39 ischaemic stroke) each year from 2011. CONCLUSIONS: Higher-than-optimal blood cholesterol concentrations are a leading cause of mortality in New Zealand. Modest reductions in blood cholesterol levels could have a major impact on population health within a decade.