Trace Minerals Flashcards
Trace Minerals
Microminerals; Nutrients needed by body in very small amounts (less than one-hundreth of 1% of total body weight); Concentrations in body highly regulated, Normal body function necessitates optimal range, Toxicity at intakes far above estimated
Trace Mineral Content of Food
Dependent upon composition of soil and water, Processing of foods, Many dietary components and factors within body affect bioavailability
Trace Minerals Dietary Need for Body
1 ppm or less
Examples of Trace Minerals
Iron, Zinc, Selenium, Iodine, Fluoride, Copper, Manganese, Chromium, Molybdenum
Iron
Dietary choices lead to not sufficient intake, Others consume too much iron; Transport of oxygen to tissues, Energy production, Maintenance of immunity, Synthesis of amino acids, hormones and neurotransmitters
Iron Function
Proteins: Hemoglobin (RBC) and Myoglobin (Muscle cells)
Hemoglobin Role
Oxygen-transferring protein of RBC that transports oxygen from lungs to body tissues, Hemoglobin accounts 80% of body’s iron
Heme VS Nonheme
Heme-Animal flesh
Nonheme-Plants
Factors that affect Iron Absorption
Increase: Gastric acid, Heme iron in food, High body demand for RBC (blood loss, high altitude, physical training, pregnancy), Low body stores of iron, Meat protein factor, Vitamin C
Decrease: Phytic acid, Oxalic acid, Polyphenols (Coffee, Red Wine), Full body stores, Excess minerals, Reduced gastric acid output, Antacids
RDA Iron for Adults
Males: 8mg/day
Females (19-50): 18mg/day
Females (51+): 8mg/day
Food Sources of Iron
Red meat, Fish, Poultry, Eggs, Legumes, Dry Fruits
Meat Fish Poultry (MFP) Factor
Associated with digestion of meat, fish, poultry and enhances absorption of iron
Iron Absorption
Varies with individuals health, life stage and iron needs/status, Varies 2-35% with average 18%, Enhanced with higher needs like pregnancy and other life stages with rapid growth
Anemia
Severe depletion of iron stores that results in low hemoglobin and small, pale, red blood cells (microcytic, hypochromic)
Nutrient Deficient Anemia
Iron, Cobalamin (Vitamin B12), Protein, Other Vitamins (B6)
Other Conditions that lead to Anemia
Hemorrhage, Genetic abnormality, Chronic disease states (Cancer, Hypothyroidism, Cardiovascular disease), Drug toxicity
Populations Vulnerable to Iron Deficiency
Infants, Adolescents, Women in childbearing years and Pregnant women
Symptoms of Iron-Deficiency Anemia
Fatigue, Anorexia, Reduced capacity to work, Poor immune response, Impaired cognition function
Treatment of Iron-Deficiency Anemia
Depends upon underlying cause and severity, Dietary modifications, Supplements, Appropriate medications, Severe iron deficiency anemia require blood transfusion, iron injections, intravenous iron therapy and treatment in hospital
Toxicity
10% population in US is positive iron balance, 1% iron overload; Two types- Hemochromatosis and Hemosiderosis; Iron overload with heart disease (oxidized LDL)
Zinc
Concentrated in bone, liver, kidney and muscle tissues; Amount in body is 1.5-2.5g
Zinc functions
Cofactor for more than 100 enzymes, Cellular growth, Bone formation, Cell mediated immunity, Part of insulin, Thyroid function, Behavior and learning
RDA for Zinc
Males (19-50): 15mg/day
Females (19-50): 12mg/day
Zinc Deficiency
1960-Children and adolescent boys in Egypt, Iran and Turkey; Rapid growth phases associated with higher zinc
Populations Vulnerable to Zinc Deficiency
Alcoholics, Trauma, Lacto-Vegetarians, Pregnant women, Elderly, Post-surgical patients
Zinc Deficiency Symptoms
Growth retardation, Skeletal abnormalities, Defective collagen synthesis, Poor wound healing, Delayed sexual maturation (children), Hypogeusia (diminished taste)
Significant Food Sources of Zinc
Protein-containing foods- Meat, fish, poultry; Whole grains, Vegetables
Metabolism of Zinc
Zinc is absorbed by intestinal cells, Attached to albumin and transferrin and circulated in blood, Excess stored in liver as metallothionein, Pancreas uses zinc to make digestive enzymes, Some losses in urine, skin, blood and semen
Selenium
Antioxidant, Cofactor for Glutathione Peroxidase; Selenium-poor soil correlates with cancer incidence
RDA Selenium for Adults
Adults: 55microg/day
Upper level: 100microg/day
Selenium Deficiency
Keshan disease, Kashin-Beck’s disease
Keshan Disease
Cardiomyopathy, Congestive heart failure, Necrosis of heart tissue
Kashin-Beck’s Disease
Disorder of bones and joints of hands, fingers, elbows, knees and ankles in children and adolescents; Occurs due to necrosis (death) of growth plates of bones and joint cartilage
