340 likes | 366 Views
This lecture note explores the significance of minerals in health, covering major and trace minerals, their roles in hypertension, nerve impulse balance, muscle contraction, and bone structure. It delves into the importance of calcium, magnesium, sulfur, and trace minerals like iron, zinc, selenium, and iodine in various bodily functions. The text discusses the impact of mineral deficiencies or toxicities, detailed regulatory mechanisms involving hormones like calcitriol, parathyroid hormone, and calcitonin, and how minerals contribute to vital processes like oxygen transport and nerve cell function.
E N D
Chapter 8 Water & Minerals: The Ocean Within
A Note to My Students • Please use these lecture notes in addition to the previous lecture notes on chapter 8 • The material is the same, but has been reorganized so that you can better understand that nutrients work together to serve a similar purpose/function • I have added my own thoughts to some of the slides so that you will not miss the main points • Email me or have office hours with me if you have any further questions on the material
Understanding Minerals • Minerals • Inorganic • Not destroyed by heat, light, acidity, alkalinity • Micronutrients (needed in small amounts) • Grouped as: • Major minerals (>100 mg/day) • Trace minerals (<100 mg/day)
Minerals in Foods • Found in plant (soil) and animal (diet) foods • Found in drinking water: sodium, magnesium, fluoride • Mineral absorption limited by several factors: • GI tract length • Competing minerals (ex. megadose) • High-fiber diet contain phytates (iron, zinc, manganese, calcium) • Oxalate (calcium)
Major Minerals and Health Mineral status significantly affects health Play critical parts in hypertension and osteoporosis
Hypertension • Fluid balance (blood, sweat, tears) • Sodium, Potassium, and Chloride • In our kidney: maintain balance of electrolytes to pull water across a wall of cells from the bloodstream bladder • Hypertension: high blood pressure • Diet: • High sodium, low potassium • More salt less water removed = higher BP
Nerve Impulse Balance • Neurons send messages electrical signals using charged chemicals • Sodium (Na+): outside • Chloride (Cl-) : outside • Potassium (K+): inside • Calcium (Ca2+):out, at end of axon
Steps: • At rest: Na+ is outside, K+ is inside • Overall, electrical charge is negative inside than outside • Stimulus opens Na+ ion gates: Na+ in • Action Potential is created signal is transmitted
Nerve Impulse Balance • Transmission of a nerve impulse is rapid and self-propagating (like dominoes) • Transmission of nerve impulses depends upon a difference in charge across the cell membrane
Bone Structure Hydroxyapatite: a crystalline mineral compound of calcium and phosphorous Supplies Ca and P blood and soft tissues Bone cells Osteoblasts Osteoclasts Fluoride promotes the deposition of Ca and P in bones and teeth
Blood Calcium • Regulation of blood calcium levels • Calcitriol/Vitamin D • Parathyroid hormone • Calcitonin • Why control blood calcium? • Important for muscle contraction and nerve impulses • If too high non-responsive • If too low spasms, convulsions
Regulation of Blood Calcium (Calcitonin and Parathyroid Hormone)
Magnesium • Function • Participates in more than 300 types of enzyme-driven reactions such as energy metabolism • Cardiac and nerve function • Main Storage: Bones
Protein Shape • Sulfur helps proteins maintain their functional shapes such as skin, hair, nails • Disulfide Bridges
Trace Minerals • Trace Minerals: • Iron, Zinc, Selenium, Iodine, Copper, Manganese, Fluoride, Chromium, Molybdenum • Cofactors for enzymes • Components of hormones • Participate in many chemical reaction • Essential for: • Growth • Immune System
Brain and Nervous System • Nerve cell protection • Iron helps produce myelin sheath • Nerve cell communication: • Iron helps produce neurotransmitters
Oxygen Transport • Hemoglobin vs. Myoglobin • Both require iron to help stabilize its structures
Iron • Deficiency: • Iron-deficiency anemia • Toxicity: • Adult doses can cause poisoning in children • Hereditary hemochromatosis – a genetic disorder in which excessive absorption of iron results in abnormal iron deposits in the liver and other tissues.
Detoxification Molybdenum • Enzymecofactor for sulfite oxidase: sulfite sulfate • Sulfur is critical in our ability (cytochrome P450) to detoxify unwanted contaminant in our liver, and to detoxify heavy metals
Antioxidant Superoxide dimutase (SOD): Cu-Zn SOD Mn-SOD Selenium is part of Glutathione Peroxidase: antioxidant enzyme Glutathione made from Sulfur Molybdenum: Sulfite Sulfate
Thyroids • Thyroid hormone helps regulate body temperature, basal metabolic rate, reproduction, and growth • Iodine: thyroid hormone production (T3, T4) • Selenium: converts thyroid hormone to its most active form (T3)
Cretinism (Iodine Deficiency during Pregnancy) • Severely stunted physical and mental growth due to deficiency of thyroid hormones, usually due to maternal hypothyroidism • Other signs: thickened skin, enlarged tongue, or protruding abdomen.
Fluoride Functions Promotes the deposition of calcium and phosphate in bones and teeth Food sources Fluoridated water Balance Excess can cause fluorosis: discoloration and “specks” on teeth; weakens teeth. The fluoridation debate
Fluorosis Fluoridated water responsible for about 40% of fluorosis Fluoridated toothpaste responsible for about 60% of fluorosis
Absorption vs. Inhibition • Enhances Absorption: • Vitamin C and Iron • Vitamins A, C, E and Selenium • Inhibition/Competition: • Copper, Iron, Zinc, (& Calcium) • Magnesium, Manganese, Calcium (& Iron) • Copper and Molybdenum • Oxalate: Calcium (and non-heme iron) • Phytates: All the minerals
Relationships • Need vitamins B1, B6, and iron to convert Tryptophan to B3 • Copper & Iron • Works with ceruloplasmin, a copper-dependent enzyme required for iron transport. • Copper & Zinc • Wilson’s disease (genetic disorder that increases copper absorption) • Selenium & Iodine • Goiters: Iodine deficiency can be caused by selenium deficiency
Other Trace Minerals and Ultratrace Minerals Arsenic Boron Nickel Silicon Vanadium