NUTRITION: Chapter 9 - Water & Minerals

How is water essential to human life?

• Most abundant molecule in your body

• Comprises 50% to 70% of human body

• Our body can lose water through lungs, skin, urine, and feces

• Our body cannot store water

What are the different water percentages?

• Muscle: 73% water

• Adipose tissue: 10% to 20% water

• Bone: approximately 20% water

• Human body: 50% to 70% water

• As body fat content increases

  • % of lean tissue decreases and total body water decreases

• Extremely lean athletes: 70% body water

What are functions of water?

• Medium for chemical reactions and participates in it

• Distributes nutrients to cells

• Remove waste products from cells

• Lubricant for joins

• Moistens organs, GI tract, eyes, skin

• Maintains body temperature and blood volume

Define Metabolic Water

Water formed as a by-product of carbohydrate, lipid, and protein metabolism. Chemical Reaction = Metabolic water

What is the AI for total water for adult males and adult females?

Water AI for females:

• 2.7 liters per day (11 cups)

Water AI for men:

• 3.7 liters per day (15 cups)

Water comes from food and water:

• Fluid needs for women are therefore: 2.2 liters (9 cups)

• Fluid needs for men are therefore: 3 liters (13 cups)

How much water comes from food?

• Fruits and veggies are more than 80% water

• Meats contains at least 50%

List the components of water intake and water output?

Water Intake: Beverages, Foods, and Metabolic Water

Water Output: Urine, Perspiration, Respiration, and Feces

Each water output components

The greatest output is urine excretion

• Output below 500 ml is the sign of dehydration

Through skin as perspiration (insensible)

• 1+ liters each day

From lungs (insensible)

• Water vapor, difficult to measure

Small amount lost in feces

How does our body conserve fluids?

Blood pressure and concentration of solutes in blood are closely monitored by receptors in kidneys, blood vessels, and brain
Hormones participating are:

• Antidiuretic hormone (ADH)

• Angiotensin

• Aldosterone

Describe the hormone regulation of water balance

Antidiuretic hormone (ADH):

• Secreted by pituitary gland when blood volume is low

• Tells kidneys to lower water excretion which in turn raises blood volume

Angiotensin:

• Produced by the liver and activated by enzymes from kidney

• Signals adrenal glands to produce aldosterone

• Directs the kidneys to conserve sodium (and therefore water)

Aldosterone:

• Produced by adrenal glands

• Tells kidneys to conserve sodium and water

Why is it significant that water is the universal solvent?

There are so many different solutes that can be dissolved in it; ideal for chemical reactions of human metabolism.

What are the primary component of water transportation?

Blood and lymph, water acts to transport nutrients to all cells of the body

Water transports Nutrients and Waste: Protein

• Protein breakdown and produces H₂O and CO₂

• Nitrogen part of protein can’t be used for energy - has to be excreted as urea

• Increase protein intake requires = increase water intake

Water transports Nutrients and Waste: Sodium

• Increased sodium consumption equals increased sodium excretion in urine.

• Amount of urine produced is determined primarily by excess protein and sodium.

Describe how water regulates body temperature

When overheated:

• Body perspires/sweats

• 60% food chemical energy becomes heat

• 600 kcal of heat energy lost from skin

• Heat energy removed from skin

• Sweat evaporates through pores

• Body is cooled and evaporative cooling

What is water’s role as a lubricant?

• Saliva

• Mucus: Protective coating through GI tract and lungs

• Lubricating Fluids: In knees and other joints; tears in eyes

• Cerebral Spinal Fluid: Spinal cord and brain

• Amniotic Fluid: Shock absorber in mother’s womb

What happens to the body when dehydrated?

1 % to 2% body water loss → feeling of thirst
4% loss → tired, dizzy, headache
10% loss → heat tolerance lower and weakness

Unmanaged dehydration leads to kidney failure, coma and death: heat exhaustion, heat stroke, kidney stones

Is thirst a good indicator of hydration status?

Thirst is controlled by our hypothalamus. Hypothalamus sensitivity declines with age, increase dehydration risk in elderly. Athletes should consume 2 to 3 cups of water each pound lost during exercise

Explain urine production impact on water adequacy

Typical urine production is 1 liter; less than 500 ml (2 cups) = concentrated urine and increase work by kidneys

Color or urine determines adequacy:

• Clear or light yellow = good hydration

• Dark yellow and pungent = poor hydration

Which three MyPlate food groups supply the most water?

Vegetables, Fruits, and Protein groups

Effects of consuming too much water?

Over hydration:

• Kidney exceeds processing ability

• Sodium becomes diluted in blood

Water Intoxication:

• Potentially fatal condition

• Occurs with high intake of water

• Results in severe dilution of blood and other fluid compartment

Hyponatremia:

• Dangerously low blood sodium level

• Swelling of brain, nerves, fluid in lungs

What is the difference between hard and soft water?

Hard water:

• Contain high levels of calcium and magnesium

• 89% of homes have hard water

• Soap does not lather

Soft Water:

• Contains a high level of sodium

• Cleaner clothes

Hard water can be converted to soft water: Increasing sodium could increase hypertension

Is bottled water healthier than tap water?

Americans consume 29.2 gallons bottle per year. Standards for quality, contaminant levels are identical for bottled and tap water.

Bottled water produced in U.S. is processed municipal tap water. Extra packaging to provide bottled water

• Over time, plastics break down

What are guidelines for safe use of water bottles?

• Repeated use, choose stainless steel bottles

• Choose reusable bottle with wide mouth (easier to wash)

• If using plastic, look for recycling codes 2 and 4 - breakdown are least harmful

• Avoid plastic bottles with recycling code 3 and 7 unless they have BPA free

• Recycle scratched or cracked bottle, bacteria can grow inside

• Do not store plastic in hot car, plastic will break down

What are Minerals?

Individual chemical elements: can’t be broken down any futher

When are minerals essential?

Dietary inadequacy cause physiological or structural abnormality; addition to diet reinstates health

Categorize amount minerals are needed in diet each day

• Major: need 100 mg+ per day

• Trace: need less than 100 mg per day

• Ultratrace: trace amounts in diet, not essential to human health

Define Bioavailability

Refers to the extent a substance, nutrient, or drug is absorbed from a product and reaches the bloodstream to be used by the body

What factors affect bioavailability? (absorption and storage of minerals in the body)

Age, gender, genetic variables, nutritional status, diet, prescription dugs, fiber content of diet.

Where does minerals absorb in the human body?

Majority absorbed in small intestine

What causes lower absorption of minerals? What about increase?

Lower:

• High fiber diets can lower absorption of iron and zinc

• Higher Zinc intake lowers copper absorption

Increase:

• Vitamin C increases Iron

• Vitamin D increases Calcium

Define Ultratrace Mineral

A mineral present in the human diet in trace amounts but that has not been shown to be essential to human health

Are ultratrace minerals essential for humans? List examples of ultratrace minerals.

They are not. Arsenic, boron, nickel, silicon, and vanadium

Preservation of Minerals in Food

Are lost from plant foods during processing
Refined grains = lower levels of vitamin E, B vitamins, and trace minerals

• Iron added as part of enrichment

• Selenium, Copper, Zinc are not added back

Which MyPlate sources have the most Minerals?

Grains and Proteins

Define the NaK+ Pump

What Na⁺ is pumped out of the cell → K⁺ (slight negative charge) enters to balance loss of positively charged Na⁺ inside of cell.
The difference in charge allows the nerve impulse transmission

Define Depolarization and Repolarization

Depolarization: Process in which cell membrane is temporarily disrupted
Repolarization: During nerve impulse transmission; Restoration of resting state of nerve cell membrane

How can minerals be toxic?

Avoid intakes above 100% of DV on supplement labels. Harmful interactions with other nutrients can occur. Look for USP (United States Pharmacopeial Convention).

Should people take individual mineral supplements? Why or why not?

It should be avoided unless needed. Having similar sizes and same electrical charge causes minerals to compete with each other for absorption → will decrease the absorption and metabolism.

Where are minerals stored in the body?

Bone: Calcium, phosphorus, magnesium, and fluoride
Liver: Iron, copper, zinc, and some trace
Others stored in muscle tissue, organs, glands
Some remain in bloodstream

What is Sodium?

• Table salt = sodium chloride (NaCl)
  40% sodium and 60% chloride

• 1 tsp of salt = 2400 mg sodium

What are the functions of sodium?

• Adds flavor to and preserves food

• Digestive tract absorbs almost all

• Helps maintain fluid balance and nerve impulse conduction

• Helps absorption of some nutrient (that is, glucose)

• Blood levels vary only slightly

What are some groups and symptoms of sodium deficiency?

Groups at risk:

• low sodium diet

• excessive sweating (athletes)

• persistent vomiting or diarrhea

Symptoms: Muscle cramps, nausea, vomiting, dizziness, shock, and coma

What is the CDRR for sodium?

• ages 14+ reduce intakes if they are above 2300 mg per day

• DV = 2300 mg

• Reducing sodium = reduce the risk for cardiovascular disease and high blood pressure

• About 95% adults in U.S. exceeds the CDRR

List food sources of sodium in your diet

High sodium foods:

• Packaged and processed foods

• Fast food

• Canned foods

• Frozen prepared meals

Low sodium foods:

• Fruits and veggies

• Whole grains

• Meats w/o sauces

• Unprocessed foods

Which organ regulates the amount of sodium in your blood?

Kidneys

Why is too much sodium be avoided?

• Increases urine output leading to dehydration and increases blood pressure

• Research links excessive sodium to overweight & obesity

Try to aim for the AI of 1500 mg

Define sodium sensitivity

a measure of how your blood pressure responds to salt intake

What are functions of potassium in the body?

• Maintaining water balance

• Nerve impulse transmission

• Principal positively charged intracellular ion

• Increasing potassium intake can help lower blood pressure

• Low blood levels from chronic diarrhea, vomiting, laxative abuse is life-threatening problem

What is Hypokalemia?

a life-threatening problem, low blood potassium. symptoms include loss of appetite, muscle cramps, confusion, and constipation.

What can cause potassium deficiency?

• Chronic diarrhea

• Vomiting

• Laxative abuse

• Alcohol abuse

• Eating disorders

• Very low-calorie diets

How is potassium intake related to blood pressure?

Food rich in potassium is important in managing high blood pressure, also known as hypertension. Potassium can reduce the effects of sodium

Where does potassium gets absorbed?

from small intestine and large intestine

What is the adequate intake of potassium?

AI for adults: 4700mg
DV used on levels: 3500 mg
Typical North American consumption: 2000-3000 mg per day

What are food sources of potassium?

milk, potatoes, beef, coffee, tomatoes, orange juice, fruits, veggies, whole grains, dried beans, and meats

What happens if you exceed potassium intake?

• Typical food intakes do not lead to potassium toxicity in people with healthy kidneys

• If kidney function is poor, potassium builds up in blood, inhibits heart function and decreases heartbeat

  • No Upper Level (UL) has been set

What are the functions of chloride in the body?

• Component of stomach acid (HCI)

• Immune response, used as white blood cells attack foreign cells

• Nerve function

Primary negatively charged ion in extracellular fluid.

Chloride Deficiency

From prolonged vomiting (bulimia or severe flu) causing acid-base disturbance due to large loss of stomach acid. Deficiency is unlikely because dietary salk intake is so high

Chloride Excess

Because of increased salt intake, average North American intake of chloride is elevated. Plays a role in blood pressure.
UL is 3600 mg per day

How is chloride intake related to blood pressure?

Its important that aging adults consciously control salt intake to decrease the risk of developing hypertension

Getting Enough Chloride

AI is 2300 mg per day
Based on 40:60 ratio of sodium
Chloride in salt:

• 1500 mg sodium: 2300 mg chloride

DV used on food label is 5400 mg

What are food sources of chlroide?

Fruits, veggies, chlorinated water, salt (NaCl)

What percentage of calcium in the body is found in bones?

99% of calcium in the bones

What are some critical functions of calcium?

40% of all minerals in body - bone growth, maintenance, and repair

• Muscle and nerve function

• Blood clot formation

• Cellular metabolism, enzymes, and hormonal responses

• Maintaining cell integrity

• Promoting cell differentiation

Calcium Deficiency

Blood calcium level is tight regulated within narrow range. Hormonally controlled actions reestablish normal blood calcium levels

• Bones release calcium

• Intestines absorb more calcium

• Kidneys retain more calcium in the blood

• When blood calcium levels are too low or too high, its most likely due to kidney disease

What causes calcium deficiency?

• Kidney diseases, hormonal abnormality, or medications

• If blood calcium falls below a critical point, muscles cannot relax after contraction and nerve function is disrupted

• Result is tetany in which muscles become stiff or twitch involuntarily

Define Tetany

A body condition marked by sharp contraction of muscles and failure to relax afterwards, usually cause by abnormal calcium metabolism

Define Osteoporosis

Presence of a stress-induced fracture or a T score of 2.5 or lower. Porous and fragile bones due to low mineral density. Usually in older ages

What role does vitamin D play in calcium metabolism?

Notable enhancer of calcium absorption. It build bones and keep them strong.

What factors reduce calcium absorption?

Anti-nutrients such as oxalates, tannins, and phytic acid foods of plant origin. These compounds chelate (bind to) calcium in the digestive track and diminish calcium absorption.

What are food sources of Oxalates, Tannin, and Phytates?

Oxalates:

• sweet potatoes, collard greens, spinach, and rhubarb

Tannin:

• Tea and some legumes

Phytates:

• whole grains, raw beans, and nuts

Calcium Absorption increased by…

• Growth, pregnancy, lactation

• High levels of parathyroid hormone and vitamin D

• Lactose present in diet

• Food contents moving through GI tract

  • Acidic environment of stomach

What is the RDA for calcium?

• RDA is 1000 mg per day for adults up to 50

• RDA is 1200 mg per day for adults 51+

Rule of 300s used to estimate calcium intake:

• 300 mg for food consumed throughout day

• 300 mg for each cup of milk, calcium fortified beverage, tofu, almonds

What are some nondairy food sources?

Protein: Quinoa and soy foods
Calcium: Dark leafy greens, broccoli, chia seeds & flaxseed, fortified foods
Vitamin D: Sunlight, fortified breakfast cereal & orange juice
Potassium: Sweet potatoes, beet greens, tomatoes
Vitamin B-12: Fortified foods like cereal, soy milk, meat subsituttes

Avoiding too much calcium

UL is 2500 mg
Calcium supplements can cause: gas, bloating, & constipation
High intake of calcium can:

• Increase risk of kidney stones

• Increased urinary and blood calcium levels leads to headaches, kidney failure, tissue calcification, and decreased absorption of other minerals

What is the function of phosphorus?

Component of hydroxyapatite

• Contributes to bone and teeth strength

Part of DNA and RNA

• Critical for cellular replication

Primary component of ATP
Allows enzymes and B vitamins to function
Component of phospholipid membrane
Maintains blood pH and fluid balance

How much phosphorus is adequate amount?

RDA:

• 700 mg for adults

• 12500 mg, from 9 to 18

Average daily adult consumption: 1200 mg to 1600 mg

What effect does Vitamin D have on phosphorus absorption?

Vitamin D enhances phosphorus absorption

Is a deficiency of phosphorus likely? Why or why not?

It’s unlikely in healthy adults because its widespread in food and beverages and efficiently absorbed. If theres not enough, kidney compensates by increased reabsorption of phosphorus

What are the primary food sources of phosphorus?

Milk, cheese, meat, bread, nuts, fish, breakfast cereals, brand, and eggs. Absorption 55% to 80%

What are the risks of excess intake of phosphorus?

High intake increases risk of tissue calcification and stone formation. Chronic imbalance in phosphorus-to-calcium ratio can increase risk of low bone mineral density
UL is 3 to 4 grams per day

What are the functions of magnesium?

• Bone rigidity

  • Stores 60% of the body’s magnesium

• Nerve and hear function

• Muscle relaxation after contraction

• Assists in 300+ enzymatic reactions

• Resistance to tooth decay

  • Lower risk of type 2 diabetes

What are the primary good sources of magnesium?

Plant sources:

• found in chlorophyll

• Squash, whole grains, bran, beans, nuts ,seeds, broccoli

Animal products:

• Milk and meats

Chocolate
Hard tap water
Coffee (espresso, not brewed)

Magnesium: Deficiency

• Irregular heartbeat, sometimes accompanied by weakness, muscle pain, disorientation, seizures

• Decreased bone strength and bone volume

• Poor bone development

• Decreased bone formation

Alcoholism increase risk of deficiency

• Dietary intake may be poor

• Alcohol increases magnesium excretion in the urine

Who is at greatest risk of developing a magnesium deficiency?

People with malabsorptive diseases, heavy perspiration. prolonged bouts of diarrhea or vomiting

When is magnesium toxicity most likely to occur?

It occurs in people who have kidney failure or overuse over-the-counter medications of magnesium. Older people are at particular risk.

Getting enough magnesium

RDA:

• 400 mg per day for men

• 310 mg per day for women

DV on food labels: 400 mg per day
Average U.S. consumption is less than RDA

• Should increase consumption of magnesium-rich foods

Refining grains reduces magnesium content by 80%

Magnesium Absorption

High phosphorus, low protein, and high fiber (phytate) diet reduces absorption.
Magnesium loss can be caused by:

• Heavy perspiration

• Prolonged vomiting or diarrhea

• Diuretic use

• Alcohol abuse (increases urinary Mg excretion)

Avoiding Too Much Magnesium

UL: 350 mg per day
Excessive Mg intake causes diarrhea
Nonfood sources can cause problems: dietary sources rarely problematic

What are the functions of Iron (Fe)?

Part of hemoglobin and myoglobin. Used as part of many enzymes, proteins. Needed for brain and immune function. Helps detoxify drugs in the liver. Contributes to bone health

What is a hemoglobin?

Iron-containing part of the red blood cell that carries oxygen to the cells and carbon dioxide away from the cells. Heme iron portion is also responsible for the red color of blood

What is a myoglobin?

Iron-containing protein that binds oxygen in muscle tissue

What are iron deficiency symptoms? How do these symptoms relate to the roles of iron in the body?

Fatigue, pale skin, always cold, loss of appetite, reduced work capacity. It can be caused by:

• growth and increased blood volume (ex: pregnancy)

• blood loss during menstruation

• blood loss from ulcers, colon cancer, hemorrhoid

What is anemia?

Lack of oxygen getting to the tissues. Its very common among females, especially during childbearing due to menstrual blood loss.

What are the stages of Iron-Deficiency?

Stage 1:

• Iron stores become depleted, but no physiological impairment is observed

Stage 2:

• Amount of iron in transferrin is depleted

• Some physiological impairment occurs

• Heme production is decreased

• Activities of enzymes that require iron as a cofactor are limited

Stage 3:

• Red blood cells are small (microcytic), pale (hypochromic), and reduced in number

• Oxygen-carrying capacity of red blood cells declines

What are heme and nonheme iron? What can you do to enhance your aborption of nonheme iron?

Heme Iron: Iron provided from animal tissues in the for of hemoglobin and myoglobin

Nonheme Iron: Iron provided from plant sources, supplements, and animal tissues other than in the forms of hemoglobin and myoglobin

What is hemochromatosis?

a disorder of iron metabolism characterized by increased iron absorption and deposition in the liver and heart. this eventually poisons the cells in those organs

The iron added to foods and in most dietary supplements is

nonheme iron

What are the functions of zinc (Zn)?

Immunity: Vital for white blood cell formation and function
Other Functions:
Wound healing, protein synthesis, and DNA synthesis

What are good sources of zinc?

Protein-rich diets.
Adult consumes about 10 to 13 mg per day