diet provides only 6 to 7 mg of iron per 1,000 kcal. Women have difficulty achieving this high intake, because they generally have a relatively low caloric intake, and the usual U.S. Therefore, the Recommended Dietary Allowance (RDA) for women 11 to 50 years of age is 18 mg/day, but for men 19 years and older is only 10 mg/day. Because of iron losses during menstruation, women in their reproductive years require higher iron intakes than men. As a component of hemoglobin and myoglobin, it functions as a carrier of oxygen in the blood and muscles. The committee identifies such gaps in knowledge and suggests directions for research. Data from animal feeding experiments are also incomplete. Furthermore, most of the evidence is not related to dietary exposure but focuses, for example, on inhalation exposure in the workplace. Most such studies have focused on cadmium, chromium, and selenium. Interactions between the various trace elements are also briefly considered.Įpidemiologic data on the relationship between many of the trace elements and the incidence of diseases such as cancer, cardiovascular disease, and hypertension are incomplete. Also discussed are aluminum, cadmium, mercury, arsenic, and lead these elements have not been demonstrated to be essential for humans but were reviewed by the committee because they are frequently ingested as contaminants in food or water. This chapter is a summary of the role of the following essential trace elements in the etiology and prevention of chronic diseases: iron, zinc, fluoride, selenium, copper, chromium, iodine, manganese, and molybdenum. The difference between toxic intakes and optimal intakes to meet physiological needs for essential trace elements is great for some elements but is much smaller for others. Iron, as a constituent of hemoglobin and myoglobin, also plays a vital role in the transport of oxygen.Īll trace elements are toxic if consumed at sufficiently high levels for long enough periods. Trace elements function primarily as catalysts in enzyme systems some metallic ions, such as iron and copper, participate in oxidation-reduction reactions in energy metabolism. Some of them are known to be nutritionally essential, others may be essential (although the evidence is only suggestive or incomplete), and the remainder are considered to be nonessential. The second slide presentation, Poetry Terms focused on things like types of poems, sound elements, and figurative language that apply especially to teaching poetry.Trace elements (or trace metals) are minerals present in living tissues in small amounts. At the end of the presentation, there is also a full list of the terms with definitions ready to print out for your kids. I chose the examples from a variety of sources – most of them literature, of varied types, that kids will recognize. In the PowerPoint, most terms are introduced one per slide with definitions and good examples. If you could use a copy of just the list, you can download a free copy here: It’s a long PowerPoint that I’ve recently posted in my TPT store with the idea that teachers could pull it out throughout the year as they introduce various literature topics. Here is the list of terms that I’ve chosen to include in my Literary Terms slide presentation. What other categories of terms do you teach to your middle grade students throughout the year? And how do you group them? Learning terms and definitions by themselves doesn’t provide much value to kids, but they need to know, and be able to use, certain terms in order to discuss and understand what they read about literature – story elements, types of figurative language, vocabulary terms, etc.
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