Fluoride and Iron Study Quiz

Trace Minerals

• Trace minerals are needed in amounts less than 100mg per day in the diet.
• Body storage is less than 5 grams for most trace minerals.
• Iron, zinc, copper, manganese, selenium, iodine, fluoride, chromium, and molybdenum are examples of trace minerals.

Iron (Fe)

• Total body content of iron is 0.004% of body weight.
  • Men: 3.6 grams (40-50 mg/kg body weight)
  • Women: 2.4 grams (35-50 mg/kg body weight)
• Storage sites include bone marrow, muscle, liver, and spleen.
• Hemoglobin (Hb) in red blood cells (RBCs) accounts for 80% of the body's iron.

Iron Functions

• Major function in cellular respiration, transporting oxygen and CO2.
• Functional iron (oxygen) and storage iron (iron) are the two major forms in the adult human body.
• Hemoglobin transports oxygen in the blood to body cells and carries CO2 away for elimination by the lungs.
• Myoglobin serves as an oxygen reservoir within muscle to make oxygen available for muscle contraction.

Iron Recycling

• Liver and spleen dismantle red blood cells (RBCs) and package iron into transferrin.
• Excess iron is stored in ferritin and hemosiderin.
• Transferrin transports iron in the blood .
• Iron-containing hemoglobin in RBCs carries oxygen.

Types of Dietary Iron

• Heme iron comes from animal products and accounts for about 10% of daily iron intake.
• Heme iron is well absorbed (about 25%).
• Non-heme iron comes from plant products and accounts for about 90% of daily iron intake.
• Non-heme iron is less well absorbed (about 17%).
• Non-heme iron exists in 2 forms: ferrous (Fe++) and ferric (Fe+++).

Iron Absorption

• Heme iron is absorbed as part of the heme group.
• Non-heme iron is absorbed in the ferrous form (Fe2+).
• Iron that enters the blood is converted ferric iron (Fe3+).
• Transferrin transports iron to liver, bone, and other body cells.

Factors Affecting Iron Absorption

• Acidity of digestive environment (antacids reduce absorption).
• Vitamin C (increases absorption).
• Fructose.
• MFP factor and protein.
• Tannic acid (tea, coffee, nuts) (reduces absorption).
• Fiber.
• Oxalates (spinach, greens) (reduce absorption).
• Calcium and phosphorus.
• EDTA (found in food additives) (reduce absorption).
• Lead (reduces absorption).

Iron From Meals

• A working estimate of absorbable iron can be calculated from 5 components of a meal:
  • Total iron (mg)
  • Heme iron
  • Nonheme iron
  • Vitamin C
  • MFP factor

Iron Availability from Meals

• Meals can be classified as low, medium, or high based on iron content, vitamin C, and meat/fish/poultry (M,F,P).
• Choosing a meal combination carefully can increase iron absorption.

Iron Deficiency

• Iron stores are depleted, the ability to synthesize hemoglobin is reduced.
• Iron deficiency anemia takes a long time to develop.
• RBC lifespan is 120 days (4 months).
• Symptoms include fatigue, headache, and pale skin.
• Causes include insufficient dietary iron, decreased iron absorption, and hemorrhaging (excessive blood loss).
• Iron deficiency in athletes can occur during strenuous exercise (sports anemia), especially in women who menstruate.
• Iron deficiency is estimated to effect 80% of the world's population.

Zinc

• The adult body stores about 2 grams of zinc (.002% body weight).
• Zinc is found in all tissues, but high concentrations are found in muscles and bones.
• Other high concentration areas include male reproductive organs (prostate glands, sperm), pancreas, and liver.
• Mucosal cells in the intestine store excess zinc in metallothionein.
• Metallothionein releases zinc to albumin and transferrin for transport to other tissues.
• Zinc deficiency in children can lead to delayed growth, delayed sexual maturation.

Zinc: Functions and Deficiencies

• Sexual maturation (puberty) in males.
• Growth in children.
• Component of insulin (regulates blood glucose).
• Wound healing (synthesis of collagen).
• Taste perception.
• Transports Vitamin A.
• Involved in the functioning of over 300 different enzymes, including superoxide dismutase.

Zinc Toxicity

• Vomiting, diarrhea, headaches.

Iodine

• Total body iodine: 20 mg.
• 75% is stored in the thyroid gland.
• The rest is distributed in skeletal muscle, blood, and ovaries.
• Iodine in foods is converted to iodide in the body.
• Iodine is needed to produce thyroid hormones (thyroxine and triiodothyronine).

Iodine: Metabolism and Function

• Iodine functions in forming two thyroid hormones:
  • Thyroxine (T4)
  • Triiodothyronine (T3)
• The thyroid hormone, thyroglobulin releases T4 and T3 into the blood.
• This causes increased oxygen utilization and higher basal metabolic rate (BMR).

Iodine Deficiency

• Goiter: thyroid gland swelling, caused by low iodine in the diet.
• TSH(Thyroid stimulating hormone): is released when iodine levels are low.
• TSH controls thyroid metabolism by increasing the size and number of thyroid cells.
• Cretinism: severe iodine deficiency during pregnancy affecting the fetus, leading to mental and physical retardation.
• Goitrogens interfere with thyroid function.
  • Goitrogens include cabbage, brussel sprouts, cauliflower, broccoli, mustard seeds, strawberries, peanuts, soybeans, and peaches.

Iodine Toxicity

• Toxicity occurs when intakes are 25-50 times the Dietary Reference Intake (DRI).
• Possible symptoms include overactive thyroid and enlarged thyroid gland.

Selenium

• Main function is as an antioxidant (spares vitamin E).
• Part of the enzyme glutathione peroxidase, which prevents free-radical formation and protects cell membrane destruction.
• Selenium deficiency can lead to Keshan's disease (heart disease).
• Keshan's disease is prevalent in areas with poor soil selenium content.

Selenium Toxicity

• Works as a pro-oxidant
• Found in regions where soil is high in selenium.
• Symptoms of selenium toxicity include damage to the nervous system (CNS), skin, hair, and nails.

Copper

• The body stores about 100mg of copper.
• Highest amounts are found in muscles, liver, and brain.
• Ceruloplasmin is a copper-protein complex in plasma.
• It's important in iron metabolism, absorption, and hemoglobin formation.
• Copper is an essential part of defense against free radicals (superoxide dismutase).
• Copper is necessary for collagen synthesis.
• Copper is used in energy metabolism (ETC) (cytochrome C oxidase).

Copper Deficiency(rare)

• Animal research indicates copper deficiency can raise blood cholesterol and damage blood vessels.
• Excess zinc, iron, or vitamin C interferes with copper absorption.
• Menkes disease is a rare genetic disorder with a defect in copper absorption from the intestine.
• Symptoms include nerve tissue degeneration, skeletal abnormalities, steely texture hair, and/or patches of white hair.

Copper Toxicity (rare)

• Toxicity is from higher intake in supplements, not from diet.
• Cupric oxide supplements are common sources.
• Symptoms include: vomiting, diarrhea

Chromium

• Major function is to enhance insulin activity in glucose metabolism (glucose tolerance factor (GTF)).
• Essential for maintaining the rate at which glucose is removed from blood used by muscles and liver.
• Chromium deficiency can cause impaired glucose tolerance.

Chromium Dietary Sources/DRI

• GTF has been purified in brewers yeast/therefore is found in yeast, bread, and beer.
• Main dietary sources include whole grains, nuts, and meats.
• AI (males): 35ug/day
• AI (females): 25ug/day
• No upper limit (UL) of chromium has been established.

Molybdenum

• Cofactor for many enzymes and plays a role in nucleic acid metabolism (DNA, RNA)
• Important in uric acid formation
• Molybdenum is important in the mobilization of ferritin iron from the liver.
• RDA: 45ug/day
• UL: 2mg/day
• Dietary sources include milk, grains, legumes, and organ meats.

Fluoride

• The body contains less than 1 gram of fluoride.
• Absorption is mainly in the stomach and small intestine.
• About 50% is retained in teeth and bones.
• Protects bone and dental tissue.
• Bone containing fluoride is more stable and resistant to degeneration (may prevent osteoporosis).
• Fluoride helps teeth to resist decay.
• When bones/teeth become calcified a crystal called hydroxyapatite is formed.
• Fluoride replaces the OH group on the hydroxyapatite crystal to make fluoroapatite.
• Fluoride intake is important for developing strong, healthy teeth.

Fluoride Dietary Sources

• Drinking water is a common source of fluoride (not all water supplies).
• Toothpaste, fish, and tea are also sources of fluoride.

Fluoride Toxicity

• Toxicity occurs with above 20 mg intake/over a number of years.
• Symptoms include mottled or stained teeth.
• Fluorosis occurs when there is higher content of fluoride in water.

Test your knowledge on the findings from the Brantford-Sarnia-Stratford fluoridation study and iron metabolism in the body. This quiz covers the effects of fluoride on dental health and the types of iron absorbed from different food sources. Discover key recommendations regarding fluoride levels in water and the physiology of iron absorption.