Chapter 12 The Trace Elements

Copyright 2010, John Wiley & Sons, Inc. Review on Sodium and nerve conduction

Copyright 2010, John Wiley & Sons, Inc. Trace Elements Talk The trace elements include  Iron  Zinc  Copper  Manganese  Selenium  Iodine  Fluoride  Chromium  Molybdenum.

Trace Minerals They are required in amounts less than 100 mg per day. Trace elements have been difficult to study, as they are difficult to remove from the diet. Rate of bioavailability is a concern for trace elements. Copyright 2010, John Wiley & Sons, Inc.

Lack of which trace element is the most common nutritional deficiency worldwide? copper iodine iron zinc

Copyright 2010, John Wiley & Sons, Inc. Iron Talk Iron from the diet is absorbed into the intestinal mucosal cells. Iron from animal products is heme iron.  Heme iron is more efficiently absorbed than nonheme iron. Iron from plant products is nonheme iron.  Iron cookware can be a source of nonheme iron in the diet.

Copyright 2010, John Wiley & Sons, Inc. Heme Group

Copyright 2010, John Wiley & Sons, Inc. Iron in the Diet

Copyright 2010, John Wiley & Sons, Inc. Which of the following is a good source of heme iron? a)beef b)chicken c)salmon d)spinach

Copyright 2010, John Wiley & Sons, Inc. Heme Iron Absorption Fe2+= ferrous form. Acids help to keep iron in ferrous form, which is more easily absorbed. Ie) Vit C can enhance absorption 6x. Fe3+ ferric iron Excess iron stored in the liver as ferritin Most iron loss is due to blood loss. Iron is conserved in normal cell death Meat can enhance absorption of non- heme iron.

Copyright 2010, John Wiley & Sons, Inc. Iron in the Body Ferritin is the major iron storage protein. Transferritin is an iron transport protein in the blood. Iron is essential for the delivery of oxygen to cells. Two oxygen-containing proteins, hemoglobin and myoglobin, contain iron. Most of the iron in the body is part of hemoglobin, which is the iron containing protein in blood.

Copyright 2010, John Wiley & Sons, Inc. Which is the best indicator of iron stores in the body? ferritin hematocrit hemoglobin transferrin

Copyright 2010, John Wiley & Sons, Inc. DRIs for Iron

Copyright 2010, John Wiley & Sons, Inc. Iron Deficiency When iron is deficient, hemoglobin cannot be produced. When there is insufficient hemoglobin, red blood cells are microcytic and hypochromic and unable to deliver sufficient oxygen to the tissues. This is known as iron deficiency anemia. It is estimated that as much as 80% of the world’s population may be iron deficient and 30% suffer from iron deficiency anemia. People low in iron and other minerals can exhibit pica

Iron Deficiency Copyright 2010, John Wiley & Sons, Inc. 1.Low iron stores 2.Low iron in plasma 3.Low iron in RBC

Copyright 2010, John Wiley & Sons, Inc. Iron Toxicity and Overload Iron is essential for cellular metabolism, but too much can be toxic. A UL has been set at 45 mg/day from all sources. Iron poisoning can be life-threatening. It can damage the intestinal lining and cause abnormalities in body pH, shock and liver failure. Iron overload can happen over time and accumulates in tissues such as the heart and the liver. Hemosiderin is an insoluble iron storage compound produced by the body when iron exceeds the storage capacity of ferritin. The most common form of iron overload is hemochromatosis.

Copyright 2010, John Wiley & Sons, Inc. Which of the following is not a true statement? Cooking in iron skillets can provide dietary iron Vitamin C enhances the absorption of iron Phytates in cereal enhance the absorption of iron Calcium supplements decrease iron absorption

Copyright 2010, John Wiley & Sons, Inc. ___________ is an inherited condition that causes individuals to absorb and accumulate too much iron. hemochromatosis hematocrit absorption syndrome hyperferritosis reverse anemia

Copyright 2010, John Wiley & Sons, Inc. Zinc Talk Zinc is essential in the diet for growth and development. Zinc from animal sources is better absorbed than zinc from plant sources (where it is bound to phytates). Zinc can be bound by phytates, affecting bioavailability. Sprouting and fermenting deactivates. Refined grains are a poor source because zinc is lost during milling and not added back.

Zinc talk Absorption  In order to pass from mucosal cells into the blood, zinc must bind to metallothionein. This also binds copper. Functions  Zinc is the most abundant intracellular trace element.  Zinc is involved in the functioning of over 300 different enzymes, including superoxide dismutase, important for protecting cells from free radical damage.  Gene expression: proteins containing zinc fold around it to form a loop or finger which can bind to regulatory regions on DNA. (binds to: Vit A, Vit D, sex hormones, etc) Copyright 2010, John Wiley & Sons, Inc.

Zinc Talk Zinc for colds  Can prevent cold virus from binding to cells of the mucous membranes of nose and throat  Many studies show that it can decreased duration if consumed within 24 of symptom onset  Would not work in supplement form. Deficiency  Poor growth/development, skin rash, neurological change, impaired reproduction, skeletal abnormalities, reduced immune function  Can mimic deficiency states of A or D. Copyright 2010, John Wiley & Sons, Inc.

Zinc in the Diet

Copyright 2010, John Wiley & Sons, Inc. The symptoms of zinc deficiency include all of the following hair loss impaired reproduction reduced immune function

Copyright 2010, John Wiley & Sons, Inc. Copper Talk Copper may be important in helping to prevent certain types of anemia. The richest dietary source of copper is organ meats. Seafood, chocolate, nuts, seeds and whole-grain foods are also good sources % of consumed copper is absorbed. Affected by other minerals, antacids, Vit C. Copper must travel bound to proteins (albumin, ceruloplasmin) because copper ions can trigger oxidation leading to cell damage. The RDA for copper for adults is 900 micrograms per day.

Copper talk Functions  Iron and lipid metabolism  Connective tissue synthesis  Maintenance of heart muscle  Function of immune and nervous system.  A part of superoxide dismutase (SOD) Copyright 2010, John Wiley & Sons, Inc. Most common deficiency is anemia. It can also cause skeletal abnormalities similar to scurvy.

Copyright 2010, John Wiley & Sons, Inc. The following are functions of copper connective tissue synthesis maintenance of heart muscle functioning of the central nervous system

Copyright 2010, John Wiley & Sons, Inc. Manganese Talk Manganese is a constituent of some enzymes and an activator of other enzymes. Manganese-requiring enzymes are involved in amino acid, carbohydrate and cholesterol metabolism, cartilage formation, urea synthesis and antioxidant protection. Manganese, like copper and zinc, is needed for the activity of a form of superoxide dismutase. The best sources of manganese are whole grains and nuts. A naturally occurring Mn def has never been reported, but has occurred under lab conditions.

Copyright 2010, John Wiley & Sons, Inc. Selenium Talk The selenium content of plant foods, such as grains and seeds, depends on the selenium content of the soil in which they are grown (true for all minerals) Selenium functions via its interaction with ‘selenoproteins’ of which glutathione peroxidase is one. Similar to Superoxide dismutase it protects cells against oxidative damage.

Selenium Talk Selenium deficiency can lead to Keshan disease, affecting the heart muscle. (maybe a combo of viral infection and Se deficiency). Symptoms of selenium deficiency include muscular discomfort and weakness. There may be a connection, still being researched, between diets low in selenium and higher incidences of cancer. Copyright 2010, John Wiley & Sons, Inc.

Selenium in the Diet

Copyright 2010, John Wiley & Sons, Inc. Iodine Talk The iodine content of food depends on the soil where plants are grown or where animals graze. Soil near the ocean or sea is higher in iodine than soil inland. Most of the iodine in the diet comes from iodized salt. Iodized salt is salt fortified with iodine. “Natural” sea salt may be very low in iodine. More than half the iodine in the body is found in the thyroid gland. Iodine is an essential component of thyroid hormones, including thyroxine.

Copyright 2010, John Wiley & Sons, Inc. What is the primary function of iodine in the body? an antioxidant, to reduce the number of free radicals a component of hemoglobin a component of thyroid hormones, which regulate metabolic rate it functions in carbohydrate metabolism

Copyright 2010, John Wiley & Sons, Inc. Thyroid Hormones

Copyright 2010, John Wiley & Sons, Inc. A deficiency of iodine often causes an enlarged thyroid gland that forms a) a blockage of arteries leading to the heart b)a cyst c)a goiter d)a shmoiter

Copyright 2010, John Wiley & Sons, Inc. Iodine and Thyroid Hormones

Copyright 2010, John Wiley & Sons, Inc. Iodine Talk When the supply of iodine is adequate, the body can produce the needed thyroid hormones. The RDA for iodine for adult men and women is 150 micrograms per day. The RDA for iodine is higher during pregnancy and lactation. Consuming diets high in goitrogens, such as cabbage, cassava and millet, limits the bioavailability of iodine. Iodine deficiency may result in hereditary cretinism. The UL for adults is 1100 micrograms of iodine per day. Iodine toxicity is possible.

Copyright 2010, John Wiley & Sons, Inc. Substances that interfere with the utilization of iodine or with the function of the thyroid gland are called deleterious iodine compounds goitrogens thyroid function abusers (TFA) thyroid interference aggregates

Copyright 2010, John Wiley & Sons, Inc. Chromium Talk Dietary sources of chromium include brewer’s yeast, liver, nuts and whole grains. Cooking in stainless steel can increase food’s chromium content. Chromium is involved in carbohydrate and lipid metabolism.

Copyright 2010, John Wiley & Sons, Inc. Marginal chromium deficiency has been linked to breast cancer polio strokes type 2 diabetes

Copyright 2010, John Wiley & Sons, Inc. Fluoride Talk Fluoride is important for dental health. Fluoride is present in small amounts in almost all soil, water, plants and animals. The most common sources of fluoride are fluoridated water, tea, marine fish eaten with their bones, such as canned salmon or sardines, and topical toothpaste. Tea contributes to Fl intake in countries that drink large amounts (1-6mg fl per liter) Water and toothpaste contributes to FL in the U.S. ( mg/ liter) Calcium-rich foods reduce the bioavailability of fluoride.

Copyright 2010, John Wiley & Sons, Inc. Fluoride Toxicity

Copyright 2010, John Wiley & Sons, Inc. Summary of Trace Elements

Copyright 2010, John Wiley & Sons, Inc. Summary of Trace Elements

Copyright 2010, John Wiley & Sons, Inc. Benefits and Risks of Trace Element Supplements

Copyright 2010, John Wiley & Sons, Inc. Which mineral functions to protect the body from oxidative damage and also helps synthesize thyroid hormone? copper manganese selenium zinc

Copyright 2010, John Wiley & Sons, Inc. Chapter 12 Copyright 2010 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein..