Macro-mineral content of milk obtained during early lactation from mothers of premature infants

Milk from mothers giving birth prematurely was analyzed for Na, C1, K, Mg, Ca and P concentrations. The data presented are from analyses of milk samples representative of complete 24-hour expressions and collected serially over the first 29 days of lactation from mothers giving birth at term (FT) and mothers giving birth prematurely (PT).Mineral composition of FT and PT milks was similar during the first month of lactation. With the exceptions of Mg and P, the concentrations of the minerals studied were higher initially than at the end of the fourth week of lactation. From these data, intakes of premature infants fed their own mothers' milk can be estimated and compared to predicted mineral requirements for the premature infant. On the basis of this comparison, we suggest that the quantities provided of Na, C1, K and Mg, but not Ca and P, would be adequate to meet requirements of premature infants during the early weeks of life.     

The Human Milk Contents of Iron, Copper, Zinc, Calcium and Magnesium in a Population with a Habitually High Intake of Iron

The contents of iron, copper, zinc, calcium and magnesium were determined in human milk samples from 18 Ethiopian and 23 Swedish women. The Ethiopian women belonged to two groups with different socio-economic situations, a non-privileged and a privileged group. Both groups had an excessively high dietary iron intake–20 to 30 times that of the Swedish women–from the iron-rich traditional diet. In spite of this, the mean concentrations of iron in the milk, as well as of zinc and magnesium, were similar in all three groups. The mean copper concentration, however, was significantly lower in the Ethiopian than in the Swedish milk samples, the lowest mean value occurring in the privileged group. In contrast, a significantly higher mean calcium concentration was found in milk samples from the Ethiopian women than from the Swedish, the highest mean concentration being noted in the non-privileged group. The levels of minerals in breast milk showed no correlation to the birth weight of the infants or the length of gestation. Our data suggest that an excessively high dietary iron intake does not increase the breast milk content of iron in mothers with a good iron status. The reasons for the differences in the content of copper between the Ethiopian and Swedish milk samples are unclear. The higher calcium content in milk from the Ethiopian mothers, despite a low dietary calcium intake may be a result of an increased endogenous cholecalciferol synthesis due to greater exposure to sunshine.     

RESURVEY OF THE NUTRIENT CONTENT OF CANNED FOODS

After a 25 to 30 year period, the National Canners Association is resurveying the nutritive value of canned foods. Most of the earlier data are still valid even though significant changes have taken place in agricultural practice.     

Evolutionary events culminating in specific minerals becoming essential for life

Summary The environment in which living organisms evolved was apparently a primary determinant of which elements became essential for life. The first organic materials and, ultimately, life forms most likely were formed in an ancient sea containing minerals that provided structural integrity and catalytic ability to the first complex organic substances. The site at which life began has been suggested to be at the edge of the sea near sediments, or around a hydrothermal system. The strongest circumstantial evidence supports a hyperthermophilic beginning. Regardless of the site, the biological importance of elements tends to parallel oceanic abundance, but in higher forms of life this parallelism apparently has been mitigated by a natural selection process that resulted in some elements becoming more important because of their superior abilities over other elements to perform vital functions. The converse to biological importance is that toxicity of elements and oceanic abundance tends to be inversely related. The basis for this relationship may be that the efficiency of homeostatic mechanisms to cope with a high intake of a specific element probably reflects upon the exposure of an organism to the element during its evolution. Thus, a study of evolutionary events may be helpful in predicting and comprehending the essential and toxic nature of mineral elements in humans. Received: 24 February 2000, Accepted: 20 March 2000     

天津市社区老年人血清矿物质水平调查

目的了解天津市老年人8种健康相关的矿物质元素营养水平,为科学合理指导老年人改善膳食结构提供依据。方法采集714例社区老年人静脉血,用电感耦合等离子体-质谱仪(ICP-MS)对血清矿物质进行分析测定。结果血清矿物质中存在1种或1种以上元素缺乏的人高达92.7%,其中Zn缺乏最严重,其次是Mn,其余依次为Mg、Cr、Fe、Ca、Cu、Se,分别占总人群的79.3%、73.4%、58.5%、42.4%、39.8%、23.0%、1.5%、0.6%。此外,血清矿物质水平存在性别差异,其中血清Fe男性高于女性,而血清Ca、Cr、Cu低于女性。结论天津市老年人血清矿物质水平普遍低下,提示在日常生活中应注意相关元素的摄取,积极改进膳食结构。     

Interactions between Active Ingredient Ranitidine and Clay Mineral Excipients in Pharmaceutical Formulations

Excipients play an important role in pharmaceutical formulations. Many clay minerals, because of their large specific surface area and inert behaviour in reactions with active ingredients, are commonly used as excipients. In this study, the uptake of ranitidine (RT), the active ingredient of Zantac, on and released from palygorskite (Pal), kaolinite (Kao), and talc was evaluated under different physicochemical conditions. The results showed that the uptake of RT on these minerals was limited to the external surface areas only. Cation exchange and electrostatic interactions were responsible for the RT uptake on Pal and Kao, resulting in a monolayer sorption. In contrast, multilayer RT uptake was found on the talc surfaces. Under different desorbing conditions, significant amounts of sorbed RT remained on the solid surface after 5 h of desorption. The results suggest that the sorptive interactions between the active ingredients and the excipients may not be neglected in pharmaceutical formulations, should these minerals be used as additives and/or excipients.     

The Mineral Content of Mexican Fruits and Vegetables

As part of the development of new food composition tables for Mexico, a number of fruit and vegetable samples, grown in Mexico, were purchased fresh from the main market in Mexico City. After washing and drying to remove contaminants, the samples were freeze dried and analyzed for the major elements (Na, K, Ca, P, Mg, Fe) by flame photometric and spectrophotometric procedures and for the minor and trace elements (Cu, Zn, Mn, Co, Cr, Cd, Pb) by atomic absorption spectrophotometry. The results are compared with those from the United Kingdom and German food composition tables. In general there were no consistent differences between the European and Mexican data, though the P content of Mexican fruits tended to be lower. There were noticeably higher Pb levels in Mexican fruits than those of United Kingdom origin, while root and green vegetables showed similar Pb levels.     

Regulation of mineral metabolism from fetus to infant: metabolic studies

Optimal mineral intake is crucial, especially during the period of rapid growth that occurs during infancy and childhood. Two minerals that have been found to play key roles during this period are iron and zinc. Supplementation studies have shown that these minerals have significant effects on birth weight as well as on weight and height increase during childhood. However, because a myriad of nutritional factors influence growth, it has often been difficult to characterize the role of any given mineral on fetal and early childhood growth. Stable iron and zinc isotopes can be used to study how the mineral status of iron- and zinc-deficient pregnant women affects their ability to absorb and transfer iron to the fetus. Furthermore, these isotopic tracers can be employed to examine the ability of infants to modify mineral absorption over time as the mineral stores of birth are depleted. Further studies using stable mineral isotopes during gestation, infancy and childhood will provide additional information on the regulation of mineral absorption and transport during these key periods of growth.     

Review of polyphenol‐rich products as potential protective and therapeutic factors against cadmium hepatotoxicity

Recently, the growing attention of the scientific community has been focused on the threat to health created by environmental pollutants, including toxic metals such as cadmium (Cd), and on the need of finding effective ways to prevent and treat the unfavorable health effects of exposure to them. Particularly promising for Cd, and thus arousing the greatest interest, is the possibility of using various ingredients present in plants, including mainly polyphenolic compounds. As the liver is one of the target organs for this toxic metal and disturbances in the proper functioning of this organ have serious consequences for health, the aim of the present review was to discuss the possibility of using polyphenol‐rich food products (e.g., chokeberry, black and green tea, blueberry, olive oil, rosemary and ginger) as the strategy in protection from this xenobiotic hepatotoxicity and treatment of this heavy metal‐induced liver damage. Owing to the ability of polyphenols to bind ions of Cd and the strong antioxidative potential of these compounds, as well as their abundance in dietary products, it seems to be of high importance to consider the possibility of using polyphenols as potential preventive and therapeutic agents against Cd hepatotoxicity, determined by its strong pro‐oxidative properties. Although most of the data on the effectiveness of polyphenols comes from studies in animals, the fact that some of them are derived from experimental models that reflect human exposure to this metal allows us to assume that some polyphenol‐rich food products may be promising protective agents against Cd hepatotoxicity in humans.     

How minerals may influence the development and expression of immunity to endoparasites in livestock

This review attempts to explain how dietary mineral intake may affect the immune system, with particular reference to gastrointestinal nematode infestations of livestock, and considers its significance for other gut infections as well as for other species. Of the 56 minerals found in mammalian tissues, 16 are currently considered to be essential, and a further 13 probably essential, for cell and tissue function. To date, eight of these have been shown to affect the function of the mammalian immune system directly. Nine others have roles in physiological pathways such as neurological or endocrine function, or protein or carbohydrate metabolism, which in turn regulate the immune system. The remainder may in the future be shown to have immunologically specific roles. The pathogenesis of mineral effects on immunity involves a number of pathways and molecular mechanisms. Major areas requiring further investigation are the relationship between deficiency of minerals and in vivo immune-mediated protection against disease, in particular diseases of the mucosa, and the mechanisms by which the minerals or their deficiency exert their effect on immunity. Research is also required into the possibility that animals in the process of acquiring gut immunity have higher requirements for minerals.