Trace minerals
Essential mineral nutrients. Found in human body in amounts less than 5 grams. Sometimes called microminerals.
Iron
(Fe++ and Fe+++). One of the most important/abundant trace minerals. Cofactor (mineral that works with an enzyme to facilitate a chemical reaction). The most common nutrient deficiency worldwide. Most iron is contained in Hemoglobin (oxygen-carrying proteins).
Heme and non-heme iron
Heme: the iron-holding part of hemoglobin and myoglobin proteins. Heme iron: found only in animal foods (meat, poultry, fish): 10% total iron consumed/day is heme; 25-35% heme iron is absorbed. Non-heme iron: found in both plant/animal foods: 90% total iron consumed/day is non-heme.
Heme and nonheme iron in foods
Only foods derived from animal flesh provide heme, but they also contain nonheme iron. All the iron in foods derived from plants is nonheme iron. Heme accounts for about 10% of the average daily iron intake, but 35% of the iron absorbed. Heme Iron is absorbed better than nonheme iron!
Nonheme iron absorption
Enhanced by: 1) MFP factor: factor associated with the digestion of Meat, Fish, and Poultry. 2) Vitamin C. 3) Acids (in food and HCl in stomach). 4) Sugars. Inhibited by: 1) Phytates. 2) Fiber. 3) Oxalates. 4) Calcium. 5) Tannic acid (Tea/coffee).
Iron
Forms: 2 irons: 1) Ferrous iron (reduced state) Fe++; and 2) Ferric iron (oxidized state) Fe+++. Chief function: part of hemoglobin (oxygen carrier in blood), part of myoglobin (oxygen-holding protein in muscle), cellular energy utilization-electron transport chain. Foods: Red meats, poultry, fish, shellfish, eggs, legumes, dried fruit. Deficiency and disease symptoms: Iron deficiency anemia: blue sclera of eyes, hypochromic/microcytic RBC's, decreased immunity, decreased work production, weakness/fatigue, decreased cognition, increased distractibility, itching, pale nail beds, concave (spoon) nails, decreased ability to regulate temperature, pica (geophagia-clay eating and pagophagia-ice craving). Consuming a good iron source with vitamin C increases iron absorption (hamburger and tomato, spaghetti with tomato sauce). Using cast-iron cookware adds supplemental iron to diet.
Iron Toxicity
Iron overload->liver damage->liver transplant. Symptoms: Lethargy, joint pain, organ damage, enlarged liver, death...as few as 5 iron tablets have caused death in young children. Hemochromatosis: hereditary iron metabolism defect leading to iron deposits in tissues->tissue damage...most common genetic disorder in US...affecting 1.5 million people. Hemosiderosis: long term dietary/supplementary iron overload->deposits of iron storage protein hemosiderin in liver and other
tissues.
Normal RBC and RBC in Iron Deficiency Anemia
Red blood cells are termed erythrocytes; these RBC's are normochromic and normocytic. Small RBC=microcytic; pale RBC=hypochromic iron deficiency. Anemia is termed hypochromic, microcytic anemia. Iron deficiency is the leading nutritional deficiency in the U.S., affecting 7.8 million women of childbearing years and adolescent girls, and 700,000 one- and two-year-olds.
Zinc
Chief function: Zinc is required as a cofactor by over 100 enzymes...zinc is a metalloenzyme; associated with insulin, involved in making genetic material and proteins, immune reactions, transport of Vit A, taste perception, wound healing, making of sperm, normal fetal development. Foods: Protein containing foods, whole grains, vegetables. Deficiency symptoms: decreased taste acuity, decreased wound healing, growth retardation/delayed onset of puberty, (dwarfism in Middle Eastern countries), impaired DNA/Protein synthesis, anorexia. Toxicity: Anemia, raised LDL, lowered HDL, GI upsets, renal failure, heart muscle degeneration. Other iron facts: Acrodermatitis enteropathica: rare inherited zinc malabsorption disease->additional more severe deficiency symptoms. The elderly are often zinc deficient because of decreased consumption of protein foods, whole grains, and vegetables (expensive foods)...zinc deficiency->decreased taste acuity and decreased wound healing which leads to even less consumption of good zinc sources and greater susceptibility to infection.
Zinc's routes through the body
Enterohepatic circulation of zinc from the intestines through the vascular system to the pancreas and back to the intestines.
Zinc deficiency in middle eastern countries
Stunted growth of dwarfism. Zinc deficiency was first reported in the 1960's in children/adolescent boys in Egypt, Iran, and Turkey. Children have high zinc needs because they are actively growing. Native middle eastern diets are typically low in higher zinc foods (meat) and the staple foods (legumes, unleavened breads, and other whole grain goods) are high in fiber and phytates, which inhibit zinc absorption. These zinc deficient male children and adolescents exhibit a zinc-deficient type of dwarfism that stunts growth (may only by 4 feet tall as adults), arrests sexual maturation (hypoganadism/males do not develop the capacity to reproduce), inhibits absorption of other nutrients (higher malnourished state), and impairs cognitive development. The stunted growth and arrested sexual maturation are only partially reversible when zinc is restored into the diet.
Iodine
(I-) Chief function: component of thyroid hormones which regulate growth, development, and BMR. Foods: Iodized salt, seafood. Deficiency diseases- Simple goiter (enlargement of thyroid gland due to iodine deficiency and thyroid gland malfunction). Cretinism (congenital disease characterized by mental and physical retardation caused by iodine deficiency during pregnancy). Deficiency symptoms- Goiter: enlargement of thyroid gland, hypothyroidism->weight gain and slow BMR. Cretinism: severe mental and physical retardation. Toxicity: enlarged thyroid gland and goiter...just like deficiency.
Selenium
Chief Function: antioxidant, helps regulate thyroid hormone, decreases risk of some cancers. Foods: seafood, meat, whole grains. Deficiency symptoms: Predisposition to type of heart disease characterized by cardiac muscle becoming fibrous (Keshan disease...named for a province in china where it was studied...prevalent in regions of china where soil lacks selenium...primary cause of this disease is probably a virus...but selenium deficiency predisposes people to the virus and inadequate selenium prevents the action of the virus). Toxicity: GI disorders, loss of hair and nails, skin lesion, nervous system disorders.
Copper
(Cu++). Chief function: Metalloenzyme (part of several enzymes), necessary for iron absorption and use of iron in hemoglobin formation (catalyzes oxidation of ferrous iron to ferric iron). Foods: seafood, nuts, whole grains, seeds, legumes. Deficiency symptoms: anemia, bone abnormalities. Toxicity: Vomiting, liver damage. Other copper facts: Two genetic disorders affect copper status: 1) Menkes disease (intestinal cells absorb copper, but cannot release copper into circulation->life threatening copper deficiency); 2) Wilson's disease (copper acculates in liver and brain->life threatening toxicity)...wilson's disease is controlled by reducing copper intake, using chelating agents (penicillimine), and taking zinc supplements to interfere with copper absorption.
Manganese
(Mn++). Chief Function: Metalloenzyme (cofactor for several enzymes). Foods: nuts, whole grains, leafy vegetables. Deficiency symptoms: in experimental animals: poor growth, nervous system disorders, reproductive abnormalities. Toxicity: nervous system disorders. Other manganese facts: miners who inhale large quantities of manganese on the job over long periods of time show symptoms of a brain disease, along with abnormalities in appearance and behavior.
Fluoride
Chief function: Involved in bone and tooth formation, helps make teeth decay-resistant by forming crystalline deposits in bones and teeth, fluorapatite is a stabilized form of fluoride in bones and teeth. Foods: Fluoride containing or fluoridated drinking, tea, seafood. Deficiency symptoms: Susceptibility to tooth decay. Toxicity: fluorosis (discoloration and pitting of tooth enamel caused by excessive fluoride during tooth development), nausea, chest pain, itching, vomiting. Other fluoride facts: the average cost, per person, of fluoridating drinking water for a lifetime is below $40...with an estimated savings of $3000 in dental costs.
Chromium
Chief function: associated with insulin and required for the release of energy from glucose. Foods: meat, unrefined foods, fats, vegetable oils. Deficiency Symptoms: diabetes-like condition marked by an inability to use glucose normally. No toxicity reported. Other chromium facts: Some organic compounds that enhance insulin's action are called glucose tolerance factors (GTF)...some glucose tolerance factors contain chromium. A chromium deficient individual may be diagnosed with diabetes and exhibit abnormal glucose.
Molybdenum
Chief function: cofactor for several enzymes...metalloenzyme. Foods: legumes, cereals, organ meats. Deficiency symptoms unknown. No toxicity reported in humans.
Other trace minerals
1) Nickel- cofactor for several enzymes. 2) Silicon- bone and collagen formation. 3) Vanadium- necessary for growth, bone development, normal reproduction. 4) Cobalt- Key mineral in vit B12. 5) Boron- may play a role in brain activities.
Contaminant minerals
Heavy metals: mercury and lead. Lead enters food supply in soil, water, pollution. Lead (Pb++) poisoning: Pb++ competes with Fe++ in heme structure (hemeglobin cannot transport oxygen); Pb++competes with Ca++ in the brain (brain cannot properly function). Symptoms of lead poisoning in children: learning disabilities, low IQ, behavior problems, slow growth, iron-deficiency anemia, sleep disturbances, nervous system disorders, seizures, poor coordination, impaired hearing. Symptoms of lead poisoning in adults: Hypertension, reproductive complications, kidney failure.