Thông tin tài liệu
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
Ngày đăng: 30/11/2016, 13:57
Xem thêm: chapt 09 lecture 2 , chapt 09 lecture 2