CHAPTER 14 WATER AND MAJOR MINERALS

LEARNING OUTCOMES What influences water balance and how does the body maintain water balance? How does both dehydration and water intoxication develop? Who gets it? For water and all major minerals discussed in class know the food sources, major functions, and the problems with low and high intakes of major minerals and how to avoid inadequate or excessive intakes. Know the major causes, risk factors, and treatment options for hypertension and osteoporosis 2

WATER Intracellular Fluid 2/3 of the body’s water Extracellular Fluid Interstitial and Intravascular Water content varies by age and body composition 3

WATER Body fluid also contains Solutes Electrolytes: Cations and Anions 4

WATER BALANCE: SODIUM POTASSIUM PUMP 5

Three sodium ions from inside the cell first bind to the transport protein. Then a phosphate group is transferred from ATP to the transport protein causing it to change shape and release the sodium ions outside the cell. 6

WATER BALANCE: SODIUM POTASSIUM PUMP 7 Then a phosphate group is transferred from ATP to the transport protein causing it to change shape and release the sodium ions outside the cell. Two potassium ions from outside the cell then bind to the transport protein. As the phosphate is removed, the protein assumes its original shape and releases the potassium ions inside the cel l.

FUNCTIONS OF WATER Functions of Water Maintenance of blood volume and transport of nutrients and oxygen Saliva, bile, amniotic fluid Lubrication Temperature Regulation Specific Heat Waste Product Removal 8

WATER Water is from drinks, food, and metabolism Beverage choices can add extra kcal 9

WATER CONTENT OF SELECT FOODS 10

WATER Needs Vary with body size, physical activity, environmental conditions and dietary intake AI 15 cups daily adult male, 11 cups daily adult female Based on 80% fluid intake, 20% food intake 11

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WATER Deficiency Dehydration: fluid output exceeds fluid intake Diarrhea, vomit, fever, exercise, hot/dry weather, high altitude ~ cups water recommended per pound of weight loss during exercise 13

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BODY’S RESPONSE TO DEHYDRATION 15

BODY’S RESPONSE TO DEHYDRATION 16

WATER TOXICITY Toxicity Hyponatremia Electrolytes in blood are too concentrated Side effects: headache, blurred vision, cramps, convulsions, death Who? Infants, endurance athletes 17

Your 4 year old cousin doesn’t like to drink water or milk. He is also considered overweight. What would be a good strategy to ensure he gets enough fluid? Soda Milk shakes Fruit Fruit punch 18 CASE STUDY

OVERVIEW OF MINERALS Major versus Trace Minerals Absorption Physiological need Bioavailability Competition with other minerals Competition with non minerals Oxalate Polyphenols Enhancement 19

MINERALS IN OUR BODY 20

OVERVIEW OF MINERALS Function Water balance (sodium, potassium, calcium, and phosphorus) Transmit nerve impulses (sodium, potassium, calcium) Enzyme cofactors Component of body compounds Body growth Deficiency Calcium, potassium, magnesium iron, zinc, and iodine UL 21

SODIUM Foods Sodium chloride (40% sodium and 60% chloride) 75-80% of our salt intake is from processed foods Needs AI for under age 51 is 1500 mg, for it is 1300 mg, for 70+ it is 1200 mg UL is 2300 mg 22

SODIUM CONTENT OF SELECTED FOODS 23

SODIUM Absorption via active transport in small and large intestine (sodium potassium pump) Excretion by the kidneys Function: Help absorb glucose and some amino acids in small intestine Normal muscle and nerve function Aids in water balance 24

SODIUM Deficiency Rare UL 2300 mg Hypertension, heart disease, and stroke Increased calcium loss in urine 25

HYPERTENSION Causes Risk factors Minerals and phytochemicals Drug therapy DASH diet Lifestyle modifications for prevention and treatment 26

BLOOD PRESSURE 27

TO LOWER BLOOD PRESSURE 28

DASH DIET 29

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WHO IS MOST LIKELY TO GO OVER THE UL FOR SODIUM? There is no UL for sodium A person who loves fruit A person who loves cheese A person who loves diet soda 31

POTASSIUM Foods (beans, potato, dairy, fruits, vegetables) Needs AI is 4700 mg Average intake below this Function: intercellular cation so same functions as sodium except that it decreases calcium excretion Deficiency Hypokalemia (low blood potassium) can lead to irregular heartbeat (usually from urinary losses) Increased risk of hypertension UL Hyperkalemia (high blood potassium) with poor kidney function 32

POTASSIUM CONTENT OF SELECT FOODS 33

CHLORIDE Foods- sodium chloride Needs AI 2300 mg (based on 40:60 ratio) Function Anion (-) maintains fluid balance Transmit nerve impulses, part of HCl Deficiency rare UL is 3.6 grams/day 34

CALCIUM Foods Dairy, fortified foods, green leafy vegetables Needs AI 1,000 mg to 1,200 mg U.S. intake 670 mg to 1,100 mg UL 2500 mg day (stones and calcification of organs) Who? Hyperparathyroidism and supplemental calcium 35

CALCIUM ABSORPTION 36

CALCIUM SUPPLEMENTS Calcium carbonate and calcium citrate Who should take which? When should you take it? How much should you take? Interactions Zinc, iron, and magnesium Contamination 37

CALCIUM Absorption Slightly more efficient in upper SI (more acidic) Things that influence absorption: Food source Vitamin D needed Efficiency increases during times of need Full stomach Age Fiber, oxalate, phosphorus, polyphenols (tea) 38

BLOOD CALCIUM LEVELS ARE KEPT UNDER TIGHT CONTROL 39

WHICH OF THESE INCREASES CALCIUM ABSORPTION? Taking calcium supplements with a glass of milk Taking calcium supplements with salty foods Taking calcium supplements on an empty stomach Spreading out your calcium intake throughout the day 40

CALCIUM FUNCTIONS: BONE HEALTH 41

CALCIUM FUNCTION: NERVE TRANSMISSION 42

OSTEOPOROSIS Bone Loss –Normal/low bone mass-osteopenia –Very low bone mass-osteoporosis Diagnosis –DEXA bone scan Prevention and Treatment –Bone building nutrients –Active lifestyle –Drug therapy 43

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PHOSPHORUS Foods Milk, cheese, meat, bakery products and cereals Needs RDA 700 mg/day Average intake 950 mg to 1650 mg/day Absorption: active transport and diffusion 46

PHOSPHORUS Function Major component of bone and teeth Critical to the function of every body cell (intercellular anion, part of ATP and DNA, part of cell membranes, part of many cellular message systems) Deficiency Rare but a chronic deficiency=bone loss, decreased growth and poor tooth development Preterm infants, alcoholics, diarrhea, over use of aluminum containing antacids UL 3-4 grams/day to avoid high blood concentrations 47

MAGNESIUM Foods Fruits and vegetables, nuts, coffee, milk and meats Needs RDA mg/day RDA increases by mg/day over age 30 U.S. average 80% RDA Absorption: active transport and diffusion, depends on intake, regulated by kidney 48

MAGNESIUM Functions Vital role in range of biochemical and physiological processes Helps ATP binding Pumps sodium out of cells and potassium in DNA and RNA synthesis Muscle contraction Insulin Blood pressure 49

MAGNESIUM Deficiency Who?: Excessive losses via urine or GI disorders Irregular heartbeat, weakness, muscle spasms Increased risk of osteoporosis UL 350 mg/day Supplements and nonfood items (antacids and laxatives) Kidney failure (elderly) Weakness, nausea, coma, death 50

SULFUR Needs No AI or UL set Found in sulfur containing amino acids Function Synthesis of sulfur containing compounds Stabilize the structure of protein Participates in acid-base balance No deficiency or toxicity 51

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