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Water and Major Minerals. Water. Intracellular Fluid 2/3 of the body ’ s water Extracellular Fluid Interstitial and Intravascular Body fluid also contains Solutes E.g., Electrolytes: Cations and Anions. Maintenance of Intracellular and Extracellular Fluid Balance. Transmembrane pumps
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Water • Intracellular Fluid • 2/3 of the body’s water • Extracellular Fluid • Interstitial and Intravascular • Body fluid also contains • Solutes • E.g., Electrolytes: Cations and Anions
Maintenance of Intracellular and Extracellular Fluid Balance • Transmembrane pumps • Sodium, Potassium moved against concentration gradient • Osmosis
Functions of Water • Maintenance of blood volume • Transport of nutrients and oxygen • Fluid synthesis • Lubricant in knees and joints • Solvent in metabolic processes • Temperature Regulation • Specific Heat • Waste Product Removal • urea
Water Sources & Needs • Water in Foods • Sweetened beverages provide little satiety and few micronutrients • Needs • Vary with body size, physical activity, environmental conditions and dietary intake • AI: 15 cups adult men, 11 cups adult women • Based on 80% fluid intake, 20% food intake • Needs met when intake = output
Overview of Minerals • Major versus Trace Minerals • Food Sources • Functions • Deficiencies • Calcium, potassium, magnesium , iron, zinc, and iodine • Toxicity
Sodium (Na+) • Foods • Grains, processed foods, soups and sauces • Needs • AI: 1,500mg (under age 51) • DV: 2,400mg
Sodium (Na+) • Functions • Absorption of glucose and some amino acids • Normal muscle and nerve function • Water balance • Deficiency • Rare (hyponatremia) • Excessive perspiration, diarrhea, vomiting • Excess and Upper Level • UL: 2,300mg
Potassium (K+) • Foods • Unprocessed foods: fruits, vegetables, milk, whole grains • Needs • AI: 4,700mg • DV: 3,500mg • Typical US adult intake falls below both
Potassium (K+) • Functions • Major cation inside cells • High intake suppresses renin-angiotensis system and promotes excretion of sodium • Deficiency • Hypokalemia (life-threatening) • Depletion by some diuretics • Excess and Upper Level • Hyperkalemia (also life-threatening) • In poor kidney function • No UL set
Chloride (Cl-) • Foods • Salt (NaCl) • Needs • AI: 2,300mg • Functions • Main anion in extracellular fluid • Nerve impulse transmission, HCl, immune response, acid-base balance • Deficiency • UL: 3,600mg
Calcium (Ca++) • Foods • Dairy, fortified foods, green leafy vegetables • Bioavailability issues • Needs • RDA: 1,000mg to 1,200mg, 1,300mg in adolescents • DV: 1,000mg • U.S. intake is 720mg to 1,195mg (lower in women) • Calcium supplements • Blood calcium levels regulated tightly
Functions of Calcium (Ca++) • Bone development and maintenance • Cortical and trabecular bone • Bone remodeling • Osteoblasts, osteocytes and osteoclasts • Blood clotting • Transmission of nerve impulses to target cells • Tetany • Muscle contraction • Cell metabolism • Calmodulin system
Calcium (Ca++) • Potential health benefits of calcium • Colon cancer prevention • Protects against formation of oxalate kidney stones • Blood pressure effect • Upper Level • 2500mg • Hypercalcemia can lead to kidney stones
Osteoporosis • Bone Loss • Normal/low bone mass: osteopenia • Very low bone mass: osteoporosis • Kyphosis (Dowager’s hump) • Diagnosis • DEXA bone scan • Prevention • Bone building nutrients • Active lifestyle with weight-bearing activities • Not smoking • Drug therapy
Phosphorus • Foods • Milk, cheese, meat, bakery products, and cereals • Needs • RDA: 700mg • DV: 1,000mg • Average intake is 950 mg to 1650 mg/day
Phosphorus • Functions • Major component of bone and teeth • Critical to the function of every body cell • Part of ATP • Role in hypertension prevention • Deficiency • Rare but a chronic deficiency contributes to bone loss, decreased growth and poor tooth development • Toxicity and Upper Level • UL: 3-4 grams/day
Magnesium (Mg++) • Foods • Part of chlorophyll – plant products • Smaller amounts from hard water, milk, and meats • Needs • RDA: 400mg men, 310mg women (19-30) • Increases 10-20mg over age 30 • DV: 400mg • Fewer than 25% of US adults meet RDA
Magnesium (Mg++) • Functions • Vital role in range of biochemical and physiological processes • Deficiency • Irregular heartbeat, weakness, muscle spasms • Increases risk of osteoporosis • Upper Level • 350mg from supplements and nonfood items only