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Water and Minerals

Chapter 8

"The greatest happiness you can have is knowing that you do not necessarily require happiness."
[William Saroyan]

Summary - Chapter Eight presents an overview of human needs for water, and the major and minor minerals. Water's function is described, as well as the importance of water balance. Our needs and deficiency symptoms for calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur are presented. Then our requirements for iodine, iron, zinc, selenium, fluoride, chromium, copper, molybdenum and manganese are discussed. Controversy 8 is about osteoporosis.

Learning Objectives for Chapter 8
After you have completed your study of this chapter, you should have acquired the following knowledge and skills.  You should be able to:
  • Discuss the major roles of water in the body and the amount of water needed by adults.
  • Describe how the body regulates water intake and excretion to maintain water balance
  • Compare the arguments for and against drinking bottled water.
  • Explain the role of minerals in maintaining the body's fluid and electrolyte balance and acid-base balance.
  • List the major roles and important deficiency and toxicity symptoms for each major and trace mineral.
  • List good food sources for the major and trace minerals.
  • Support claims make for calcium in preventing osteoporosis.

 

Introduction (1:01)

Intro
Water is the basis for all life. Water owes this uniqueness to the polarity of each water molecule. That polarity allows water molecules to self associate into loosely bound polymers that cause water to be liquid at room temperature. In the liquid state water becomes the medium for chemical reactions, transportation of nutrients and waste products, and even becomes part of the firmly bound water in proteins and other materials crucial to life. There is little doubt that the earliest life was possible only because of water as a medium for life to begin. All life on earth depends on water.

 

Functions of Water (1:33)

Water
  • Carries nutrients
  • Transports nutrients and wastes
  • Serves as a solvent for minerals, some vitamins, amino acids, glucose and other small molecules, and helps keep proteins and other large molecules and entities in soluble state.
  • Participates in reactions
  • Acts as a lubricant around joints
  • Serves as a shock absorber in the eyes, spinal cord, joints and amniotic sac
  • Aids in temperature maintenance

(See the margin of page 266 for factors that increase water needs.)

 

Water balance 266

Water Balance (1:46)

Water
Balance
The body's need for water exceeds the body's need of any other nutrient

Water balance is controlled in the body by separate mechanisms to manage intake and excretion.

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Intake - Governed by thirst, which is stimulated by an impulse from the hypothalamus.

Excretion - Kidneys use sodium levels to guide the rate of water excretion. Also, the kidneys may be directed by a pituitary gland hormone to conserve water.

Rapid dehydration can be fatal, as the body may not be able to respond to the need in time.

(See table 8-1 for signs of mild and severe dehydration)

 

Hard vs. Soft Water (5:20)

Hard or soft
Water can be classified many different ways.
  • "Hard" or "soft" water refers to the amount of dissolved solids. Hard water is high in Magnesium and Calcium salts usually because it originates in underground locations where these salts are present. Hard water leaves a ring around the bathtub because of precipitation with soap. Soft water, such as rainwater, has much lower dissolved solids and should not leave a residue with soap.
  • Bottled water is commercially available at different prices, and is usually made by 'deionizing', or removing dissolved solids from the water through reverse osmosis or ion exchange processes. Some bottled water arises from natural sources such as springs, and is sold at premium prices.

See website for Drinking Water Quality Standards

 

Body fluids and minerals 268

Ionic Balance (1:14)

Ionic balance
Body water is contained in cells, exists in extracellular spaces, and fills the blood vessels. These three locations for water are in equilibrium in the body, and water molecules move back and forth from location to location. The movement is controlled in various ways, but chiefly through changing concentrations of salt.

 

Ions
NaCl (a soluble compound) dissolved in water

Ions or electrolytes - These particles are soluble because their electrical charge attracts the polar water molecules.  The water molecules serve to enshroud the charged particle and incorporate it into the water's polymeric structure. Concentration of electrolytes determines movement of water between the three compartments, to maintain proper equilibrium.

Acid - Base balance - Some electrolytes gain their charges by interacting with water to gain or lose hydrogen ions. The amount of hydrogen ions present in the fluids determines the pH of the fluid. The optimum pH for life is a very narrow range of concentration. (See Figure 3-10)

 

The major minerals are calcium, phosphorus, magnesium, sodium, chloride, potassium and sulfur. They are called major minerals because they are required by the body in milligram quantities, they serve important roles in maintaining electrolyte balance, and they serve some other important roles such as building blocks and for other unique purposes.
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In this section we will describe some of the properties of major minerals.

 

Calcium 292

Calcium (2:09)

Calcium


Calcium Functions (1:35)

Calcium
functions


Calcium Balance (1:29)

Calcium
balance


 

 

 

 

 

 

Calcium Sources (3:09)

Calcium
sources
99% of calcium is stored in bones, and can be accessed as needed in the body.

Our teeth are made of the same calcium containing material, a mineral called hydroxyapatite, but in teeth, the calcium is not as readily available to the body as it is in our bones.

Replacement of some of the hydroxyapatite with a similar, fluoride-containing mineral called fluorapatite creates tooth enamel that is resistant to decay.

Physiological functions of Calcium
The 1% of the body's calcium that is not in bones or teeth is found in body fluids, and is involved in several important life processes, including:

  • regulating ion transport
  • maintaining blood pressure
  • regulating muscle contraction
  • involved in hormone secretion
  • involved in blood clotting

Calcium balance -

The calcium in bones maintains bone density, and also serves as a storehouse for calcium. As we age, the bones supply calcium for other uses, and the bones become less dense, and more fragile. That condition is called Osteoporosis, or adult bone loss. A calcium rich diet and a regular exercise program in youth and early adulthood will guard against osteoporosis.

 Osteoporosis

Calcium RDA - A Panel of the Food and Nutrition Board (The Food and Nutrition Board is part of the National Academy of Sciences Institute of Medicine) has just finished studying the most current scientific finding on calcium, Vitamin D, phosphorus, magnesium, fluoride. This resulted in the Board establishing a new RDA for calcium intake at 1400 mg/day.

Calcium Sources - Milk and Dairy products, tofu, greens and legumes are all good sources of calcium.

 

Phosphorus (3:19)

Phosphorus
85% of the body's phosphorus is found in teeth and bones. The remainder is found in body fluids and in the genetic material in cells.

Physiological functions of Phosphorus

  • phosphorous as phosphate serves as a buffer in the blood, to help control pH.
  • phosphorous in ATP, a triphosphonucleotide, delivers energy in all body processes.
  • phosphorous is a key building block in phospholipids
  • phosphorous is a key building block in RNA and DNA

Phosphorus RDA -

  • The same as calcium

Phosphorus Sources -

  • Milk and dairy products, meat and fish, legumes
 CaPhos

 

Magnesium 276

Magnesium (2:09)

Magnesium
Over half of the approximately 1 gram/kg bodyweight of magnesium is found in the bones. The remainder is contained in muscles, soft tissues and organs, with only 1% found in body fluids.

Physiological functions of Magnesium -

  • serves as a cofactor for many enzymes
  • factor in the metabolism of potassium, calcium and Vitamin D
  • serves as the muscle relaxing factor after contraction
  • holds calcium in tooth enamel
  • May help to prevent risk of heart failure, by helping to regulate heartbeat.

Magnesium RDA -

  • Around 280-350 mg/day

Magnesium Sources -

  • Most vegetables
  • Laxatives and antacids (Milk of Magnesiaâ)

 

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Sodium (2:10)

Sodium
We obtain our needed sodium from table salt. Salt is also a widely used preservative. One theory has it that in the middle ages people ate so much salt from their preserved foods that were thirsty all of the time. Since the water at that time was not pure, they turned to beer to slake their thirsts.

Physiological functions of sodium -

  • serves as the main factor in fluid and electrolyte balance in cells
  • essential to muscle contraction and nerve transmission
  • helps maintain pH balance in cells
  • may be involved with high blood pressure in some individuals

Sodium RDA -

  • Minimum requirement - 500 mg/day (no upper limit suggested)
  • Most guidelines recommend reducing sodium intake

Sodium Sources -

  • ubiquitous, it is found in all foods and on most dinner tables.

 

Potassium 281

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Potassium
Potassium is one of the most abundant positively charged ions in the body. Low potassium is dangerous because loss of potassium from brain cells makes the victim unaware of the need for water. This problem leads to a requirement for special caution when using diuretic foods or drugs.

Physiological functions of Potassium

  • needed for fluid and electrolyte balance
  • maintains regular heartbeat
  • required to be in balance with sodium

Potassium RDA

Potassium Sources

  • Fresh foods of all kinds
  • Orange juice and bananas are among many excellent sources

 

Chloride 282

Chloride (0:15)

Chloride
Chloride is a negative ion that is needed in cells and body fluids to balance positive the charges of sodium, potassium and magnesium ions.

Physiological functions of Chloride

  • it is needed for fluid and electrolyte balance
  • Needed to form part of hydrochloric acid, the digestive acid

There is no known RDA or minimum requirement for chloride.

 

Sulfur 282

Sulphur (1:29)

Sulfur
The body does not use sulfur by itself as a nutrient, but sulfur is required to be present in proteins and thiamin.

Physiological functions of Sulfur

  • Sulfur helps proteins stay rigid.

There is no known RDA or minimum requirement for sulfur.

 

Trace Minerals (0:51)

Trace
minerals
The trace minerals are named so because the body needs such small amounts that it is not possible to construct a deficient human diet. The trace minerals that have RDA's established include iodine, iron, zinc and selenium. Safe and Adequate Daily Dietary Intakes have been established for copper, manganese, fluoride, chromium and molybdenum. Human requirements are under study for arsenic, nickel, silicon and boron. Cobalt is thought to have no RDA.

 

Iodine 283

Iodine (3:37)

Iodine
Iodine is needed by the body in extremely small quantities. It is a part of the hormone thyroxin. If iodine is low in the body, the thyroid gland enlarges to try to make more thyroxin. This causes a lump on the neck known as goiter. Oversupply of iodine can also cause a lump in the neck.

Physiological functions of Iodine

  • Part of thyroxin, needed for proper synthesis of this hormone
  • Iodine deficiency in pregnant women causes cretinism in their offspring.

Iodized salt is common in developed countries, where recognition of the cause and effect relationship of iodine to goiter led to the fortification of table salt with iodine, virtually eradicating goiter in those countries.

 

 

 iodine

 

Iron 284

Iron (2:37)

Iron
All cells contain iron. Most of iron in the body is found as part of the molecules hemoglobin (red blood cell oxygen carrying protein) or myoglobin (muscle cell oxygen carrying protein).
Physiological functions of Iron
  • essential to carry and store O2 in the body
  • essential for electron transport mechanisms (production of CO2)
  • Needed to make new cells, amino acids, hormones and neurotransmitters.

Iron RDA

  • 12-15 mg/day

Iron sources

  • Cast iron cookware
  • Red meat
  • Poultry and fish
 Iron Cycle

Anemia - This is the most common worldwide deficiency disease. Plants contain phytates and other compounds that interfere with iron absorption, so people who are vegetarian or live in reduced meat consumption countries are at great risk of iron deficiency.

 

Zinc 288

Zinc (2:28)

Zinc
Zinc is in very small quantities in the body, but it works with proteins in every organ.

Physiological functions of Zinc

  • Makes parts of DNA and RNA
  • Makes Heme in hemoglobin
  • Helps the pancreas with digestive functions
  • Helps metabolize carbohydrate, protein and fat
  • Liberates Vitamin A from storage in the liver
  • Assists with free radical disposal

Zinc RDA

  • 12 - 15 mg/day (deficiencies cause mental and physical retardation).

Zinc Sources - Meats, shellfish and poultry, legumes and whole grains.

Zinc Toxicity- Zinc in high doses is toxic. Zinc in high doses inhibits iron absorption. It also seems to accelerate development of atherosclerosis.

 

Selenium 290

Selenium (3:55)

Selenium
Recent research has linked low selenium diets to prostate cancer. Other functions attributed to selenium include it being an antioxidant partner to Vitamin E. Selenium toxicity is possible, so supplementation should be approached with caution.

Selenium RDA = 50 to 70 micrograms (mg)/day

 

Fluoride 291

Fluoride (2:56)

Fluoride
Fluoride is not an essential nutrient. Fluoridated water supplies have reduced the incidence of dental caries in the USA. Fluoride is incorporated into Fluorapatite, the decay resistant mineral in enamel. Fluorosis, or brown mottling of teeth, happens in people who have too much fluoride naturally in their water.

The Estimated Safe and Adequate Daily Dietary Intake is between 1 and 4 mg.

 floride

 

Chromium 292

Chromium (4:39)

Chromium
Chromium is needed for proper functioning of insulin, and proper carbohydrate metabolism. However, no evidence is available to support claims that chromium can cure symptoms of diabetes. Widely touted as a supplement to enhance lean body tissue buildup, it has no effect whatever on body composition.

The Estimated Safe and Adequate Daily Dietary Intake is 50 micrograms/day, and is best obtained from liver, whole grains, nuts and cheeses.

 

Copper 293

Copper (1:33)

Copper
Copper helps to form the molecules of hemoglobin and collagen. A low copper diet may contribute to heart disease. Copper helps enzymes release energy. Copper deficiency is rare, but when it happens, it impairs growth and metabolism. Copper toxicity is unlikely, but can arise from over-supplementation.

The Estimated Safe and Adequate Daily Dietary Intake is between 1 and 2 mg.

 

Other Minerals 294

Other Minerals (1:20)

Other
minerals

Mineral Toxicity (2:02)

Toxicity

Interactions (1:06)

Interaction

Cold Eeze Lozenges (2:38)

Zinc
Lozenges

Romans and Lead Poisoning (1:06)

Lead
Poisoning
Molybdenum
The Estimated Safe and Adequate Daily Dietary Intake is 50 to 250 mg.
Physiological functions of Molybdenum: Molybdenum functions as part of several metal containing enzymes.

Manganese
The Estimated Safe and Adequate Daily Dietary Intake is 2 to 5 mg.
Physiological functions of Manganese: Manganese works with a number of enzymes.

 

In Conclusion:

Several other trace elements are being investigated to try to learn if RDAs or Estimated Safe and Adequate Daily Dietary Intakes can be established. Boron, cobalt, nickel, silicon, barium, cadmium, lead, lithium, mercury, silver, tin, vanadium, and even arsenic may have roles to play in proper nutrition. Remember that all trace elements can be toxic if ingested in excess.