Nutrition: Science and Applications Chapter 12 The Trace Minerals

Fluorosis

A condition caused by chronic over consumption of fluoride, characterized by black and brown stains and cracking and pitting of the teeth;

Cretenism

A condition resulting from poor maternal iodine intake during pregnancy that causes stunted growth and poor mental development in offspring;

Metallothionein

A group of proteins that bind metals; one such protein binds Zinc and copper in intestinal cells, limiting their absorption into the blood. Binds copper, and high levels can inhibit copper absorption.

Thyroid-stimulating hormone (TSH)

A hormone that stimulates the synthesis and secretion of thyroid hormones from the thyroid gland.

Iron (Fe)

Identified as a major constituent of blood in 18th century; "coloring matter" women; Most common nutritional deficiency worldwide; comes from plant and animal sources in diet; Essential for delivery of oxygen to the cells; estimated that 80% of world population is iron deficient; 30% suffer from deficiency anemia; RDA 8 mg/day for adult men 19 and older and postmenopausal women; RDA for menstruating women is 18 mg/day; RDA for pregnant women is 27 md/day; Sources: red meat, organ meats (liver, kidney),

Iron Deficiency anemia

When iron is deficient, hemoglobin can't be produced and red blood cells are small and pale and unable to deliver enough oxygen to the tissues. Anemia is the last stage of iron deficiency.

Heme iron

readily absorbed form of iron found in animal products that is chemically associated with proteins such as hemoglobin and myoglobin. Sources: Meat, poultry, and fish. Absorption ranges from 15-35%

nonheme iron

A poorly absorbed form of iron found in both plant and animal foods that is not part of the iron complex found in hemoglobin and myoglobin. Sources: Leafy green veggies, legumes and whole and enriched grains and iron cooking utensils. Absorption ranges from 2 - 20%; Vitamin C, meat, beef, fish, or poultry enhances absorption; the following interfere with absorption phytates in cereal, fiber, tannins found in tea, oxalates in leafy greens, These cause deficiencies in U.S.

Superoxide dismutase (SOD)

An enzyme that protects the cell by neutralizing damaging superoxide free radicals. One form of the enzyme requires zinc and copper for activity and another from requires manganese.

Hemochromatosis

An inherited condition that results in increased iron absorption. Most common genetic disorders in Caucasian population;

Hemosiderin

An insoluble iron storage compound that stores iron when the amount of iron in the body exceeds the storage capacity of ferritin.

Transferrin

An iron transport protein in the blood

Myoglobin

An iron-containing protein in muscle cells that binds oxygen. Enhances the amount of oxygen available for use in muscle contraction.

Hemoglobin

An iron-containing protein in red blood cells that binds oxygen and transports it through the bloodstream to cells.

Selenium (Se)

Discovered 180years ago but not recognized until 1970's for preventing heart disorders in children in China. Very popular today; Sources: Seafood, kidney, liver and eggs are excellent; good sources: grains, seeds, and dairy products; Poor sources: fruits, veggies, and water; being researched as a connection to cancer; RDA for adults is 55 ug/day;

Wilson's Disease

Due to an inherited defect in the excretion of copper and causes copper to accumulate in the body leading to toxicity; treated with Zinc supplements

Zinc (Zn)

Essentially first recognized 50 years ago by a syndrome of growth depression and delayed sexual development seen in iran and Egyptian men; Found in plan and animal food sources; Sources: Red meat, liver, eggs, dairy products, veggies, some seafood; refined grains not a good source; Most abundant intracellular trace element; Plays a role in gene expression; RDA 11 mg/day for adult men and 8 mg/day for adult women;

Trace Minerals

Iron, Zinc, Copper, Manganese, Selenium, iodine, chromium, Fluoride, molybdenum and others are required in an amount of 100 mg or less/day or present in the body at 0.01% or less of body weight.

Iodine (I)

Needed for synthesis of thyroid hormones; Found in seawater; most iodine in N.A. diet is from salt; more than 1/2 iodine in our body is located in the thyroid gland; iodine deficiency increase risk of still births and spontaneous abortions; worlds most prevalent and preventable cause of brain damage; RDA adult men and women is 150 ug/day;

Other trace elements

No RDA set: lead present only as environmental exposure; Arsenic, Boron, Nickel, Silicon and vanadium are significant to human health; Psychological role elements; aluminum, bromine, cadium, germanium, lead, lithium, tin, rubidium.

selenoproteins

Proteins that contain selenium as a structural component of their amino acids. selenium is most often found as selenocysteine, which contains an atom of selenium in place of the sulfur atom

Chromium (Cr)

Since 1950s needed for normal glucose utilization; but recently connected to insulin function; Sources: Liver, brewer's yeast, nuts and whole grains; Poor sources: Milk, veggies and fruit; cooking in stainless steel can increase intake; deficiency not a problem in U.S.; AI is 35 ug/day for men and 25 ug/day for women; Chromium supplements are marketed to reduce body fat and increase lean body tissue;

Copper (Cu)

Sources: organ meats (Liver, Kidney), Seafood, nuts and seeds, whole grain breads and cereals, and chocolate; 30-40% of the copper in a typical diet is absorbed; Absorption is reduced by high intakes of iron, manganese, and molybdenum, vitamin C, and antacids. plays a role in cholesterol and glucose metabolism; and nerve signals; deficiency is rare but most common is anemia; RDA for adults is 900 ug/day; North American diet is slightly higher than the RDA; toxicity is rare but has occured from contaminated water; cause liver damage;

Manganese (Mn)

Sources: whole grains, legumes, and nuts. Fair Sources: fruits and grains; poor sources: meat, dairy products and refined grains; Deficiency in animals causes retardation, reproductive problems, congenital malformation in offspring and abnormal brain functions; RDA n/a;

Goitrogens

Substances that interfere with the utilization of iodine or the function of thyroid gland; Sources; turnips, rutabaga, cabbage, cassave and millet; Common in Africa, uncommon in U.S.

Ceruloplasmin

The major copper carrying protein in the blood

Ferritin

The major iron storage in protein

Hepcidin

a peptide hormone released by the liver that is the primary regulator of iron homeostasis

Menkes Disease or kinky hair disease

a rare genetic disease in which there is a defect in intestinal copper absorption; Copper was used to treat;

Glutathione peroxidase

a selenium-containing enzyme that protects cells from oxidative damage by neutralizing peroxides

Keshan Disease

a type of heart disease that occurs in areas of CHina where the soil is very low in selenium. Caused by a combination of viral infection and selenium deficiency. Enlarged heart and poor hear function;

Goiter

an enlargement of the thyroid gland caused by a deficiency of iodine.

Acrodermatitis enteropathica

an inherited defect in zinc absorption that results in a Zinc deficiency; causes skin lesions, damages the eyes, increases risk of infection.

Fluoride (F)

important for dental health; Sources: fluoridated water, tea and marine fish consumed with bones; Toothpaste is biggest source in U.S.; Teflon utensils pick up fluoride but aluminum cookware decreases fluoride content; 80-90% of fluoride is absorbed; Absorption is reduced with calcium intake; used for osteoporosis treatment; AI for all sources is 0.05 mg per kg per day for everyone older than 6 months

Molybdenum (Mo)

needed to activate enzymes; content in food varies with soil content; Best Sources: milk, milk products, organ meats, breads, cereals and legumes; RDA is 45 ug/day for adults; increased for pregnancy and lactation; no adverse affects for humans; birth defects in animals;