Chapter 11: Water and the Major Minerals

Chapter 9 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)

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Amniotic fluid, joint lubricants, saliva, bile

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

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

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

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Loss of 2% or more of body weight causes muscle weakness (stay hydrated –training) – Lose significant strength and endurance

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Loss of 10%-12% – Heat intolerance

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Loss of 20% – Coma and death

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 – Require >100 mg /day – Calcium, phosphorus etc.

 Trace Minerals – Require < 100 mg/day – Iron, zinc, selenium etc.

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

-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 of Minerals  

Fe

Mg

Cu

Zn ~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 2400mg/day  Hypertension (HTN) and CVD

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Calcium (Ca) ~ not enough, esp. Women  osteoporosis

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Iron (Fe) ~ not enough, esp. Women – Men require 8 mg/day – Women require 18 mg/ day  Menstral flow  Supplements hard to digest ?

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All other Major and Trace minerals (ok) ~ balanced diet – Avoid supplementing to try and balance or optimize  Leads to mineral competition  deficiencies

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 

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 

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)

Calcium  99%

is in bones and teeth

 Makes

up 40% of all the minerals present 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 D deficiency  Polyphenols (tannins) in tea  Menopause  Aging

Ca



Ca

Ca

(phytic acid)

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

Functions of Calcium  Bone

formation and maintenance  Blood clotting  Nerve impulse transmission  Muscle contraction  Cell metabolism –Activates various enzymes

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 

Food Sources of Calcium

Bone Strength  Dependent

on bone mass and bone mineral density

 The

more there is, the stronger the bone

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 

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

Osteoporosis - Video 

Break

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” 

Osteoporosis

Bone Structure

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 

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

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Signs: – Paleness, brittle nails, fatigue, poor temperature control, poor growth – Fatigue, decreased Immune sys.

Food Sources of Iron

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!)

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 2 (Due next wed/Friday) includes – See website – Ca – Fe – Vit E – Vit C

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For next week, organic foods/ food safety – Please go see Food Inc. –Nickelodian, Downtown – 5 pts. For class assignment