Chapter 9 Water and Minerals

1. Chapter 9Water and Minerals

2. Water • 50%-70% of body weight • Musclecontains 73% water • Fat contains ~20% • Intracellular fluid • Fluid within the cells • Extracellular fluid • Fluid outside the cells

4. 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

5. where an Ion goes, H2O flows: fig 9:2 Na Na Na Na Na H2O Na Na Na

6. 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

7. Are You Drinking Enough? • Fluid recommendation: 9 cups for women and 13 cups for men as a starting point Min. 2-4 water bottles/day

8. Thirst Mechanism • Not reliable • Concerns for infants, older adults, athletes • Athletes • Weigh before and after training session • Consume 3 cups for every pound lost • Illness (vomiting, diarrhea, fever) • Get additional water

9. 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)

10. 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

12. Too Much Water • Overburden the kidneys • Low blood electrolyte concentrations • Blurred vision

13. -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?

14. Minerals • Various functions in the body • Major Minerals • Require >100 mg /day • Calcium, phosphorus etc. • Trace Minerals • Require < 100 mg/day • Iron, zinc, selenium etc.

15. For 5 pts & Make it a Half day???What do you say? • Go see “Food Inc.” the movie • Nickelodean theatre (downtown SC) • 3, 5, 7 & 9PM showtimes. . . • Answer 3 short questions (class website) • Turn in with TICKET STUB Next Wednesday • See Trailer http://www.newsday.com/entertainment/movies/ny-etfood2612909901jun24,0,6046635.story

16. -Confirming your knowledge- What are the 7 Major minerals required in the body? 1 2 3 4 5 6 7

17. -Confirming your knowledge- What are the 7 Trace minerals required in the body? 1 2 3 4 5 6 7

18. Most mineral requirements are obtained without defic. in N. American diets

19. Fe Bioavailability of Minerals Mg • ~Degree of absorption • Affected by binders in plants (oxalic acid, phytic acid) • Fibrous foods • Animal 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 <Copper) • Avoid mega-supplements (2X RDA): unless prescribed • Vitamins-mineral interactions: • Iron w/ (Vit C), Calcium w/ (Vit. D) most efficient Cu Zn

20. Mineral Toxicity • Trace minerals are more toxic • e.g. Fe, stomach irritation • Result of supplementation • Presence of contaminants (esp. Lead (Pb)) • Look for the United States Pharmacopeia (USP)-approved brands (most reliable)

21. Minerals of Concern in the Diet • Sodium (Na) ~ consume too much >2400mg/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 hard to digest ? • All other Major and Trace minerals (ok) ~ balanced diet • Avoid supplementing to try and balance or optimize • Leads to mineral competition  deficiencies

22. Sodium • Table salt (NaCl): 40% sodium, 60% chloride • 95% of ingested sodium is absorbed • Positive ion in extracellular fluid • Aldosterone regulates sodium balance • Key for retaining body water • Excretion regulated by the kidneys • Muscle contraction • Conduction of nerve impulses

23. Food Sources of Sodium • Most sodium is added by food manufacturers and restaurants • Milk and dairy products • Processed foods • Sodium content listed on the labels

25. Sodium Needs • Adequate Intake is 1500 mg for adults • Body only needs 200 mg to function • Daily Value is 2400 mg/day • Upper Level is 2300 mg • Typical intake is 4700 mg/day (US) • Sodium-sensitive individuals should restrict intake (African American)

26. Calcium • 99% is in bones and teeth • Makes up 40% of all the minerals present in the body

27. 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)

28. Decreased Absorption of Calcium Ca Ca • Rapid intestinal motility • High fiber intake (oxalic acid) • Excess phosphorus • Vitamin D deficiency • Polyphenols (tannins) in tea • Menopause • Aging Ca Ca (phytic acid)

29. Blood Calcium is Regulated • Blood level is maintained at the price of bone calcium • Blood level can be maintained despite inadequate calcium intake • Setting stage for future bone fractures

30. Functions of Calcium • Bone formation and maintenance • Blood clotting • Nerve impulse transmission • Muscle contraction • Cell metabolism • Activates various enzymes

31. Building Higher Bone Mass • Adequate diet • Healthy body weight • Normal menses • Weight-bearing physical activity • Moderate intakes of protein, phosphorus, sodium, caffeine • Non-smoker • Lower use of certain medications

32. Food Sources of Calcium

33. Bone Strength • Dependent on bone mass and bone mineral density • The more there is, the stronger the bone

34. Calcium Needs • Daily Value is 1000 mg/day • Adequate Intake is 1000 -1200 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 2500 mg/day

35. Calcium Supplements • Recommended for people who cannot incorporate Ca into their diets • Not recommended with high-zinc meal • Calcium carbonate (40% calcium) • For those with ample stomach acid • Found in antacids (TUMS) • Calcium citrate (21% calcium) • Enhances absorption due to acidity content • Recommended for older adults

36. Osteoporosis - Video • Break

37. Osteoporosis • Calcium deficiency • “A pediatric disease with geriatric consequences” • Leads to ~1.5 million fractures / year • Slender, inactive women who smoke are most at risk • “Less bones”

38. Osteoporosis

39. Bone Structure

40. Bone Growth and Mass • Rapid and continual throughout adolescence • Peak bone mass • Determined by gender, race, familial pattern, other genetic factors • Bone loss begins ~age 30 • Women experience increased bone loss after menopause • DEXA bone scan

42. Bone Mineral Density

43. 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)

44. 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)

45. 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 Ca Ca (phytic acid) Ca

46. 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

47. 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

48. 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.

49. Food Sources of Iron

50. Iron Needs • RDA is 8 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!)