Transcript Slide 1
Table 11-1, p. 379 Macrominerals Overall importance in: •Maintenance of electrolyte balance •Mineralization of bones •Enzyme cofactors •Muscle contraction •Nerve conduction The major macrominerals are: Table 11-1a, p. 379 Table 11-1b, p. 379 Average absorption about 30% Fig. 11-1, p. 381 Table 11-2, p. 382 Extracellular concentrations highly regulated by parathyroid hormone ( bone demineralization), calcitriol (calcium reabsorption), and calcitonin (decrease blood Ca2+) Fig. 11-2, p. 383 Intracellular calcium regulation is through calcium channels; intracellular concentrations are VERY LOW relative to extracellular concentrations Increases in intracellular Ca2+ can act as a second messenger signaling mechanism for many cells; involved in neurotransmitter release and other events Fig. 11-3, p. 384 Table 11-3, p. 387 Deficiency: rickets in children, hypocalcemic tetany, muscle pain, osteoporosis in adults Chronic deficiency associated with hypertension (inversely related), colon cancer (a preventative), and obesity (low calcium yields heavier weight) Toxicity: soft tissue calcification, constipation, kidney stones Phosphorus Found in: meat, poultry, fish, eggs, milk and milk products. Nuts, legumes, cereals, and grains (animal sources are better). Most in the form of phytate. Hydrolyzed in the lumen and released as inorganic phosphate; carrier mediated Phytic acid/phytate Fig. 11-7, p. 393 Functions: bone mineralization, in DNA and RNA, in nucleotide triphosphates (ie. ATP), second messenger (cAMP and IP3), phospholipids, as an intracellular buffer Deficiency: rare; anorexia, rickets, skeletal and cardiac myopathy, neurlogic problems Toxicity: rare Table 11-4, p. 394 Table 11-5, p. 398 Vertebral bodies Radius Femoral neck p. 412 Magnesium - ingested with phytate, other food sources • found in dairy products, fish, meat and seafood, as well as in legumes, apples, apricots, avocados, bananas, whole grain cereals, nuts, dark green vegetables, and cocoa, while hard water and mineral water may also supply it in fair quantities Functions: • Formation of bones and teeth • Aids in absorption of calcium and potassium • As a part of the utilizable form of ATP • Can help prevent kidney stones (along with B12) • Is used for PMS symptoms, migranes, management of premature labor Table 11-5, p. 398 Deficiency symptoms (mainly due to malabsorption, alcoholism): cardiovascular problems, including tachycardia; irritability and seizure; insomnia, poor memory, depression Toxicity: rare; diarrhea and abdominal cramping; kidney failure; coma and death Sodium No more than 2,300 milligrams of sodium a day. This is about 1 teaspoon of sodium chloride (salt). To illustrate, the following are sources of sodium in the diet. 1/4 teaspoon salt = 600 mg sodium 1/2 teaspoon salt = 1,200 mg sodium 3/4 teaspoon salt = 1,800 mg sodium 1 teaspoon salt = 2,400 mg sodium 1 teaspoon baking soda = 1000 mg sodium Most diets contain 5X this amount Sources: Virtually all processed foods Absorption: Three mechanisms (at right) Function: Water balance; blood pressure Nerve propagation Membrane potential Osteoporosis Prevalence Two Types Diagnosis Who’s at risk? Other risk factors