Trace Minerals The Trace Minerals Needed in much

Trace Minerals

The Trace Minerals • Needed in much smaller amounts • Are essential • Difficult to study due to the trace amounts needed by the body • Food content dependent on soil content • Animal sources of mineral are generally better absorbed.

Trace Minerals Iron Iodine Fluoride Manganese Molybdenum Nickel Boron Zinc Selenium Copper Chromium Arsenic Silicon Cobalt

Iron • Ferrous (Fe++) – Reduced • Ferric (Fe+++) – Oxidized • Chief functions in the body – Part of the protein hemoglobin, which carries oxygen in the blood – Part of the protein myoglobin in muscles, which makes oxygen available for muscle contraction – Necessary for the utilization of energy as part of the cells’ metabolic machinery Copyright 2005 Wadsworth Group, a division of Thomson Learning

Iron • Found in minute amount in every cell • 15% is absorbed • Heme iron Vs. Nonheme iron – 40% of iron in animal flesh is heme iron – Heme iron is better absorbed than nonheme • Vitamin C enhances absorption

Iron Absorption Copyright 2005 Wadsworth Group, a division of Thomson Learning

Some losses via sweat, skin, and urine Transferrin carries iron in blood. Some iron delivered to myoglobin of muscle cells Liver (and spleen) dismantles red blood cells, packages iron into transferrin, and stores excess iron in ferritin (and hemosiderin). Some losses if bleeding occurs Bone marrow incorporates iron into hemoglobin of red blood cells and stores excess iron in ferritin (and hemosiderin). Iron-containing hemoglobin in red blood cells carries oxygen. Stepped Art Fig. 13 -3, p. 445

Iron Sources – two forms of iron in food 1. Heme iron – meats, poultry, fish; readily absorbed 2. Nonheme iron – plants foods; less absorbed a. Absorption enhanced by Vitamin C b. Absorption diminished by phytates, oxalates, and tannic acid

Iron: Heme vs. Nonheme Copyright 2005 Wadsworth Group, a division of Thomson Learning

Functions of Iron • Hemoglobin in red blood cells – Transports oxygen and carbon dioxide – High turnover, high demand for iron • Myoglobin in muscle cells – Binds oxygen • • Electron transport chain Enzyme cofactor Immune function Drug-detoxification pathway

Iron • 2001 RDA – Men: 8 mg/day – Women (19 -50 years): 18 mg/day – Women (51+ years): 8 mg/day • Upper level for adults: 45 mg/day • Significant sources – Red meats, fish, poultry, shellfish, eggs – Legumes, dried fruits Copyright 2005 Wadsworth Group, a division of Thomson Learning

Iron • Iron deficiency is the most common nutrient deficiency worldwide • Can occur if inadequate intake or blood loss • Females are prone due to menstruation, lower iron intake & pregnancy • Preschoolers also at risk due to high milk diets Copyright 2005 Wadsworth Group, a division of Thomson Learning

Iron • Deficiency symptoms – Microcytic, hypochromic anemia (low Hgb & Hct): weakness, fatigue, headaches – Impaired work performance and cognitive function – Impaired immunity – Pale skin, nailbeds, mucous membranes, and palm creases – Concave nails – Inability to regulate body temperature – Pica (craving for ice, clay, paste, and other non-food substances) Copyright 2005 Wadsworth Group, a division of Thomson Learning

• Both size and color are normal in these blood cells • Blood cells in irondeficiency anemia are small and pale because they contain less hemoglobin

Iron • Toxicity – “iron overload”; more common in men -Hemochromatosis – genetic defect -Hemosiderosis – chronic ingestion of too much iron; more common in alcoholics -Iron poisoning – acute toxicity from overdose of iron supplements; can be deadly in small children • Toxicity symptoms – GI distress – Iron overload: infections, fatigue, joint pain, skin pigmentation, organ damage Copyright 2005 Wadsworth Group, a division of Thomson Learning

Zinc • Essential nutrient • Better absorption from animal source • Deficiencies cause growth retardation and poor sexual development

Zinc Chief functions in the body – Part of many enzymes, esp. enzymes for transfer of carbon dioxide – Associated with the hormone insulin – Involved in making genetic material and proteins – Important to wound healing, taste perception, reproduction (the making of sperm), vision (transports and activates Vit. A) & immune function Copyright 2005 Wadsworth Group, a division of Thomson Learning

Zinc • 2001 RDA – Men: 11 mg/day – Women: 8 mg/day • Upper level for adults: 40 mg/day • Significant sources – Protein-containing foods – Red meats, shellfish – Whole grains Copyright 2005 Wadsworth Group, a division of Thomson Learning

Zinc in food Mucosal cells in the intestine store excess zinc in metallothionein. The pancreas uses zinc to make digestive enzymes and secretes them into the intestine. If the body Zinc is not absorbed does not and is excreted in shed need zinc intestinal cells instead. Thus, zinc absorption is reduced when the body does not need zinc. If the body needs zinc Metallothionein releases zinc to albumin and transferrin for transport to the rest of the body. Stepped Art Fig. 13 -6, p. 453

Zinc • Deficiency symptoms – In children, growth retardation and delayed sexual maturation – Impaired immune function – Hair loss – Eye and skin lesions – Loss of appetite and abnormal taste – Depressed immune function and poor wound healing - Night blindness

Zinc • Zinc Absorption and Metabolism – Zinc Transport • Transported by the protein albumin • Binds to transferrin • Excessive iron and copper can lead to a zinc deficiency and excessive zinc can lead to an iron and copper deficiency.

Zinc • Toxicity – not likely, unless supplement abuse • Toxicity symptoms – Loss of appetite, impaired immunity, low HDL, copper and iron deficiencies Copyright 2005 Wadsworth Group, a division of Thomson Learning

Selenium Readily absorbed Excreted through the urine and feces Co-factor for glutathione peroxidase Protects the heart and other cells from oxidative damage • Works together with vitamin E • Cancer prevention • •

Deficiency of Selenium • Muscle pain • Muscle wasting • Cardiomyopathy

Food Sources of Selenium • • Fish, meat (organ meat), egg, milk, shell fish Grains, seeds, nuts dependent on soil content RDA for adults is 55 ug/day Average intake exceeds RDA

Toxicity of Selenium • • Upper Level is 400 ug/day Garlicky breath Hair loss Nausea, vomiting Weakness Rashes Cirrhosis of the liver

Iodine • Found in an ion form, iodide • Used for thyroid hormone synthesis • Regulates metabolic rate, growth, development • Thyroid gland enlarges (goiter) with low intake of iodide • Cretinism is the stunting of fetal growth and mental development as a result of low iodine diet

Iodine • Chief functions in the body – A component of two thyroid hormones that help to regulate growth, development, and metabolic rate • 2001 RDA for adults: 150 g/day • Upper level: 1100 g/day

Iodine • Significant sources – Iodized salt, seafood, bread, dairy products, plants grown in iodinerich soil and animals fed those plants (content of iodine in soils affects food content) Copyright 2005 Wadsworth Group, a division of Thomson Learning

Iodine • Deficiency disease -Simple goiter-enlarged thyroid; affects 200 million people worldwide -Creatinism- severe mental and physical retardation in infants • Deficiency symptoms – Underactive thyroid gland, goiter • Toxicity symptoms – Underactive thyroid gland, elevated TSH, goiter (also causes enlarged thyroid gland) Copyright 2005 Wadsworth Group, a division of Thomson Learning

Food Sources of Iodine • Iodized salt (1/2 tsp. meets RDA for iodine) • Saltwater fish, seafood, dairy, grains • Sea salt is a poor source (loss during processing) • Plant source dependent on soil content • RDA for adult is 150 ug/day (50 ug to prevent goiter) • Average intake exceeds RDA

Toxicity of Iodine • • Thyroid hormone synthesis is inhibited “Toxic goiter” results Consumption of seaweed Upper Level is 1. 1 mg/day

Copper • Aids in iron metabolism • Absorption dependent on body’s needs • Absorption decreased with high intakes of vitamin C, phytic acid, fiber, zinc, iron, certain amino acids

Functions of Copper • • Increases iron absorption Formation of connective tissue In superoxide dismutase Immune system, blood clot, brain development, cholesterol metabolism

Deficiency of Copper • • • Anemia Decrease WBC Bone loss Inadequate growth Pre-term infants at risk Cardiovascular disease

Food Sources of Copper • • Organ meats Seafood Cocoa Mushroom, legumes, seeds, nuts, whole-grain RDA is 900 ug/day for adults Daily Value is set at 2000 ug Average intake is about or slightly below the RDA

Fluoride • Role in prevention of cavities • Resists acid and dental caries • Fluoride inhibits bacterial growth that may cause cavities • Fluoridated water (1 ppm)

“Food” Sources of Fluoride • • • Fluoridate water (~0. 2 mg/cup) Tea Seafood, seaweed Toothpaste Adequate intake is 3. 1 -3. 8 mg/day for adults Typical fluoridated water contains 0. 2 mg/cup

Toxicity of Fluoride • • • Fluorosis Mottling of the teeth in children Limit toothpaste to pea size for children In high amounts can weaken teeth in children Upper Level is 10 mg/day

U. S. Population With Fluoridated Water Copyright 2005 Wadsworth Group, a division of Thomson Learning

Manganese • Chief functions in the body – Cofactor for several enzymes – Component of bones and glands • 2001 AI – Men: 2. 3 mg/day – Women: 1. 8 mg/day • Upper level for adults: 11 mg/day Copyright 2005 Wadsworth Group, a division of Thomson Learning

Manganese • Significant sources – Nuts, whole grains, leafy vegetables, tea • Deficiency symptoms – Rare; requirements are low • Toxicity symptoms – Nervous system disorders – Has occurred in miners inhaling large quantities of dust causes brain damage Copyright 2005 Wadsworth Group, a division of Thomson Learning

Molybdenum • High intake will inhibit copper absorption • Required by several enzymes • Deficiency rare – Increased heart and respiration rates – Night blindness, mental confusion – Edema, weakness, coma • • RDA is 45 ug/day Average intake is 75 -110 ug/day Toxicity seen in animals Upper Level is 2 mg/day

Chromium • Chief functions in the body – Enhances insulin action – CHO & lipid metabolism • 2001 AI -Men: 35 g/day – Women: 25 g/day • Significant sources – Meats (especially liver) – Whole grains, brewer’s yeast Copyright 2005 Wadsworth Group, a division of Thomson Learning

Chromium • Deficiency symptoms – Diabetes-like condition; mimics symptoms of diabetes, especially in elderly • Toxicity symptoms – None reported Copyright 2005 Wadsworth Group, a division of Thomson Learning

Other Trace Minerals • Nickel is a cofactor for certain enzymes. • Silicon is used in bone and collagen formation. • Vanadium is for growth, development, and normal reproduction. • Cobalt is a key component of vitamin B 12. • Boron may be key in brain activities. • Arsenic is useful in some types of leukemia.

Mineral Pyramid

Contaminant Minerals • Contaminate minerals are also called heavy metals. • These include mercury, lead, and cadmium. • These minerals enter the food supply through soil, water, and air pollution. • They disrupt body processes and impair nutrition status.

Contaminant Minerals • Lead toxicity symptoms in children Learning disabilities in children Low IQ Behavior problems Slow growth Dental caries Iron-deficiency anemia Sleep disturbances like night walking, restlessness, and head banging – Nervous system disorders and seizures – Slow reaction time and poor coordination – Impaired hearing – – – –