chapt 09 lecture 2

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Chapte r Water and Minerals Water  50%-70%  Muscle of body weight contains 73% water – Fat contains ~20%  Intracellular fluid – Fluid within the cells  Extracellular fluid – Fluid outside the cells Fluid Balance   Water shifts freely in and out of cells Controlled by electrolyte concentration – Have electrical charges Na, K, Cl, P, Mg, Ca   Osmosis (where an Ion goes, H2O flows) Intracellular water volume – Depends on intracellular potassium and phosphate concentrations  Extracellular water volume – Depends on extracellular sodium and potassium concentrations where an Ion goes, H2O flows: fig 9:2 Na Na Na Na Na H2O Na Na Na Functions of Water  Body temperature regulation – Water absorbs excess heat – Body secretes fluid via perspiration – Skin is cooled as perspiration evaporates – Humidity (bad) & fans (good) ~ evaporation  Removal of body waste via urine – Urea excretion (Nitrogen from Protein breakdown – Sodium excretion – Avoid concentrated urine (brownish)  Amniotic fluid, joint lubricants, saliva, bile  Are You Drinking Enough? Fluid recommendation: cups for women and 13 cups for men as a starting point Min 2-4 water bottles/day Thirst Mechanism Not reliable  Concerns for infants, older adults, athletes  Athletes  – Weigh before and after training session – Consume cups for every pound lost  Illness (vomiting, diarrhea, fever) – Get additional water Ignoring the Thirst Signal Shortage of water increases fluid conservation  Antidiuretic hormone (vassopressin)  – Released by the pituitary gland – Forces kidneys to conserve water (reduce urine flow)  Aldosterone – Responds to drop in blood pressure – Signals the kidney to retain sodium (water) Hydration  Loss of 1%-2% of body weight in fluid – Thirst signal  Loss of 2% or more of body weight causes muscle weakness (stay hydrated –training) – Lose significant strength and endurance  Loss of 10%-12% – Heat intolerance  Loss of 20% – Coma and death Bone Mineral Density The Trace Minerals Needed in much smaller amounts  Essential for health  Difficult to study  – Only trace amounts in the body Animal sources of mineral are generally better absorbed  Most Important: Iron (Fe)  Iron Found in minute amounts in every cell  18% is absorbed  Heme iron vs Nonheme iron  – Heme found in animal products better absorbed than nonheme – Meat protein factor may aid in nonheme absorption  Vitamin C enhances absorption (nonheme iron) Absorption of Iron  Determined by body’s need  Iron storage in intestinal cells  Absorbed in an acidic environment  Hindered by phytic acid, oxalic acid, high fiber, high calcium, polyphenols Ca (phytic acid) Ca Ca Ca Functions of Iron  Hemoglobin in red blood cells – Transports oxygen and carbon dioxide – High turnover, high demand for iron Myoglobin in muscle cells  Electron transport chain  Enzyme cofactor  Immune function  Drug-detoxification pathway  Iron-Deficient Anemia Most common form of anemia  Low levels of hemoglobin and hematocrit  Insufficient intake and stores  Reduction in  – Production of red blood cells – Oxygen-carrying capacity Iron Deficiency Anemia  Most at risk: – Infant, toddler, chronic blood loss, vegans, runners, and women of childbearing years  Signs: – Paleness, brittle nails, fatigue, poor temperature control, poor growth – Fatigue, decreased Immune sys Food Sources of Iron Iron Needs RDA is mg/day for adult male  RDA is 18 mg/day for female age 19 to 50  Daily Value is 18 mg  Average intake exceeds RDA for men; low for some women  Upper Level is 45 mg/day  – Take supplements/ cut them down to size – More easily digested (see product 65mg tab!) Iron Toxicity Serious, especially for children  Signs:  – Diarrhea, constipation, nausea, abdominal pain – Causes death due to respiratory collapse (shock)  Hemochromatosis – Genetic disease (5-10% N Americans) – Iron deposit that can lead to organ damage – May go undetected until organ damage at 50-60 Mineral Functions What is safe and effective food product that has nearly all of your vitamins/minerals that is not a supplement? Get Your Blood work Tested?  Diet Analysis (Due next wed/Friday) includes – See website – Ca – Fe – Vit E – Vit C  For next week, organic foods/ food safety – Please go see Food Inc –Nickelodian, Downtown – pts For class assignment [...]... with TICKET STUB Next Wednesday – See Trailer http://www.newsday.com/entertainment/movies/ny-etfood26 12 9099 01jun24,0,6046635.story -Confirming your knowledgeWhat are the 7 Major minerals required in the body? 1 2 3 4 5 6 7 -Confirming your knowledgeWhat are the 7 Trace minerals required in the body? 1 2 3 4 5 6 7 Most mineral requirements are obtained without defic in N American diets Bioavailability... and restaurants  Milk and dairy products  Processed foods  Sodium content listed on the labels  Sodium Needs Adequate Intake is 1500 mg for adults  Body only needs 20 0 mg to function  Daily Value is 24 00 mg/day  Upper Level is 23 00 mg   Typical  intake is 4700 mg/day (US) Sodium-sensitive individuals should restrict intake (African American) Calcium  99% is in bones and teeth  Makes up 40%... density  The more there is, the stronger the bone Calcium Needs Daily Value is 1000 mg/day  Adequate Intake is 1000 - 120 0 mg/day for adults  Adequate Intake is 1300 mg/day for adolescents (9-18 yrs old)  Average intake: 800 mg/day for women and 1000 mg/day for men  Upper Level is 25 00 mg/day  Calcium Supplements Recommended for people who cannot incorporate Ca into their diets  Not recommended... supplementation – Presence of contaminants (esp Lead (Pb)) – Look for the United States Pharmacopeia (USP)-approved brands (most reliable) Minerals of Concern in the Diet  Sodium (Na) ~ consume too much >24 00mg/day  Hypertension (HTN) and CVD  Calcium (Ca) ~ not enough, esp Women  osteoporosis  Iron (Fe) ~ not enough, esp Women – Men require 8 mg/day – Women require 18 mg/ day  Menstral flow  Supplements... Too Much Water  Overburden  Low the kidneys blood electrolyte concentrations  Blurred vision -Confirming your knowledge Q What is the Minimal amt of H2O from fluids that Humans require/day to replace daily loss?  What is the recommended amt of water from fluids that women and men require/day? Minerals  Various functions in the body  Major Minerals... in the body Absorption of Calcium      Amount in body is dependent on amount absorbed Requires slightly acidic environment and vitamin D Absorbed in upper part of small intestine Normally absorb 25 % of calcium in food Increase to ~60% during time of need – (pregnancy, infancy) Decreased Absorption of Calcium Ca Rapid intestinal motility  High fiber intake (oxalic acid)  Excess phosphorus  Vitamin... products are better absorbed Plants depend on mineral content of soil Refinement lowers mineral content (i.e milling Grains) Mineral-mineral competition (e.g >>Zinc vs
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