Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 13 The Trace Minerals The Trace Minerals • Essential nutrients found in the human body in <5g. • Needed in <20mg daily • Food sources varies widely • Nutrient interactions is very common Iron • The most abundant mineral on earth • The most abundant trace mineral in the body • An 130 pound woman has about 2300mg of iron in her body about the size of a dime • A 165 pound male will have about 4000mg of iron in his body • Key component of blood, highly valuable to the body • Once absorbed, very little leaves the body • ~95% of iron in the body is recycled and reused • Most iron is lost due to bleeding Iron • Occurs in two forms: – Heme – found in animal foods such as meat, poultry, and fish • Part of hemoglobin in red blood cells and myoglobin in the muscle cells • Easily absorbed by the body – Non-heme – found mostly in plants foods such as grains and vegetables • Not easily absorbed as heme iron • Compounds such as phytates in legumes rice, and grains, and polypherols in tea and soy protein inhibits absorption of non-heme iron • In general, the body absorbs only 10 – 15% of the iron ingested Iron • You can enhance absorption of iron by eating a food that’s high in vit C along with iron rich foods • As little as 25mg of vit C can double the absorption of iron • Eating non-heme iron with heme iron can also ehnance absorption • Too little or too much iron can be harmful Iron Functions • Hemoglobin and myoglobin transport Oxygen in red blood cells • Hemoglobin picks up carbon dioxide waste to the lung to be exhaled from the body • Needed for brain function, involved in the synthesis of neurotransmitter in the brain • Cofactor to enzymes • Involve in making of amino acids, collagens, and hormones Iron Factors that inhibit non-heme iron absorption; • Phytates and Fibers (found in grains and vegetables • Oxalates ( spinach, beets, rhubarb) • Calcium and phosphorus (milk) • Food additives • Tannic acid (found in tea and coffee) Iron Deficiency • Iron deficiency is the depletion of iron stores in the body • Iron deficiency anemia is the deletion of body’s stored iron accompany by low hemoglobin and hematocrit • High risk for iron deficiency – Women in their reproductive years – pregnant women – Infants and young children – Teenagers • Blood losses through bleeding • Microcytic anemia – small pale red blood cells • Iron deficency and pica Iron Deficiency – Iron deficiency is the most common form of nutritional disorder in the world • Iron deficiency anemia: – – – – – Decrease in hemoglobin levels Diminish delivery of oxygen through the body weakness, fatigue, headaches Weak immune system Pre-menopausal women, pregnant women, preterm and low birth weight children and toddlers are all at risk – Pica is craving for non nutrient substances like chalk or ice, common among pregnant women Iron Toxicity from supplementation can cause: • Constipation, nausea, vomiting, diarrhea • In the U.S. accidental consumption of supplements containing iron is leading cause of poisoning deaths in children under age 6 • Ingestion of as little as 2200mg as been shown to be fatal • The FDA requires warning label on iron supplements that contain 30mg of iron or more • Iron overload (hemochromatosis)– excessive storing of iron over several years Iron • Food sources – About half of Americans get their iron from enriched bread and other grains – Red meats, fish, poultry, shellfish, eggs contributes about 12% – Cooking food in iron skillet can increase can increase non-heme iron content Iron • RDA – Men: 8 mg/day • Adult male consume over 16mg on average – Women (19-50 years): 18 mg/day to cover loss during menstruation • Consume about 70% (13mg) of recommended intake on average – Women (51+ years): 8 mg/day – Pregnant women: 27 mg/day – Vegetarians require 1.8 time higher than non vegetarians due to components in plan foods that reduce absorption of iron • Upper level for adults: 45 mg/day Zinc • • • • Zinc is found in every cell of the body It is involved in more than 100 enzymes Not considered essential until 1974 Roles – Needed for DNA synthesis, and for growth and development – Helps keep immune system healthy – Helps in wound healing by reducing inflammation that usually accompanies wounds – Helps fight age-related macular degeneration (AMD) by working with enzymes needed to produce active c=vitamin A in the eyes Zinc • Rate of absorption varies from 15 to 40% • During digestion zinc is released in the pancreas and travel to the small intestine with dietary zinc • Zinc is excreted primarily in feces • Zinc is transported by albumin into the bloodstream • Large dose of zinc inhibit iron absorption due to iron binding to transferrin (protein that carries iron) Zinc • Deficiency symptoms – Hair loss – Loss of appetite – Impaired taste of foods – Delayed sexual maturation – impotence • Significant sources – Protein-containing foods – Red meats, shellfish – Whole grains Zinc • RDA – – – – Men: 11 mg/day Women: 8 mg/day Upper level for adults: 40 mg/day Vegetarians can have as much as 50% higher need for zinc • Toxicity symptoms – – – – Stomach pains Nausea, vomiting, diarrhea Can lower copper level in the body More than 300mg can suppress the immune system and lower HDL (good cholesterol) Iodine • Iodine is an essential mineral for the thyroid glands • The thyroid need iodine to make certain hormones that regulate the majority of the body’s cells – – – – – – Regulate body temperature, reproduction, growth, blood cell production, nerve and muscle function Influence the amount of energy released during basal metabolism Iodine Deficiency • Hypothyroidism – under activity of the thyroid hormone • Goiter – early sign of thyroid deficiency • Mental and physical retardation in babies born to mothers with iodine deficiency during pregnancy (cretinism) Iodine • Toxicity – overactive thyroid gland – Reduce the synthesis and release of thyroid hormones • RDA for adults: 150 g/day • Upper level: 1100 g/day • Significant sources – – – – Iodized salt, seafood, bread, dairy products, plants grown in iodine-rich soil and animals fed those plants Copper • Chief functions in the body – Necessary for absorption and use of iron in the formation of hemoglobin – Part of several enzymes • RDA for adults: 900 g/day • Upper level for adults: 10,000 g/day (10 mg/day) Copper • Significant sources – Seafood – Nuts, whole grains, seeds, legumes • Deficiency symptoms – Anemia, bone abnormalities • Toxicity symptoms – Liver damage Fluoride Fluoride is the safe form of fluorine, a poisonous gas Functions • Protect against tooth decay • Helps repair the enamel of the tooth that has already started to erode • Interferes with the ability of the bacteria to metabolize in carbohydrate, reducing the amount of acid Fluoride • AI – Men: 3.8 mg/day – Women: 3.1 mg/day • Upper level for adults: 10 mg/day • Significant sources – Drinking water (if fluoride containing or fluoridated) – Tea, seafood Fluoride • Deficiency symptoms – tooth decay, especially with children • Toxicity symptoms – Fluorosis (pitting and discoloration of teeth) – Occurs when teeth are forming, only infants and children up to age 8 are at risk – May occur from swallowing toothpaste or excessive use of dental products