Nutrition Chapter 12: Water and Major Minerals
sodium
the principal cation in the extracellular fluids of the body; critical to the maintenance of fluid balance, nerve impulse transmissions, and muscle contractions.
potassium
the principal cation within the body's cells; critical to the maintenance of fluid balance, nerve impulse transmissions, and muscle contractions.
mineralization
the process in which calcium, phosphorus, and other minerals crystallize on the collagen matrix of a growing bone, hardening the bone.
water intoxication
the rare condition in which body water contents are too high in all body fluid compartments.
bioavailability
the rate at and the extent to which a nutrient is absorbed and used.
solutes (SOLL-yutes)
the substances that are dissolved in a solution. The number of molecules in a given volume of fluid is the solute concentration.
cortical bone
the very dense bone tissue that forms the outer shell surrounding trabecular bone and comprises the shaft of a long bone.
artesian water
water drawn from a well that taps a confined aquifer in which the water is under pressure.
well water
water drawn from groundwater by tapping into an aquifer.
public water
water from a municipal or county water system that has been treated and disinfected.
mineral water
water from a spring or well that naturally contains at least 250 parts per million (ppm) of minerals. Minerals give water a distinctive flavor. Many mineral waters are high in sodium.
metabolic water
water generated during metabolism.
natural water
water obtained from a spring or well that is certified to be safe and sanitary. The mineral content may not be changed, but the water may be treated in other ways such as with ozone or by filtration.
spring water
water originating from an underground spring or well. It may be bubbly (carbonated), or "flat" or "still," meaning not carbonated. Brand names such as "Spring Pure" do not necessarily mean that the water comes from a spring.
carbonated water
water that contains carbon dioxide gas, either naturally occurring or added, that causes bubbles to form in it; also called bubbling or sparkling water. The FDA defines seltzer, soda, and tonic waters as soft drinks; they are not regulated as water.
purified water
water that has been treated by distillation or other physical or chemical processes that remove dissolved solids. Because purified water contains no minerals or contaminants, it is useful for medical and research purposes.
distilled water
water that has been vaporized and recondensed, leaving it free of dissolved minerals.
filtered water
water treated by filtration, usually through activated carbon filters that reduce the lead in tap water, or by reverse osmosis units that force pressurized water across a membrane removing lead, arsenic, and some microorganisms from tap water.
hard water
water with a high calcium and magnesium content.
soft water
water with a high sodium or potassium content.
binders
chemical compounds in foods that combine with nutrients (especially minerals) to form complexes the body cannot absorb. Examples include phytates (FYEtates) and oxalates (OCK-sa-lates). Some foods contain-----that combine chemically with minerals, preventing their absorption and carrying them out of the body with other wastes.
buffers
compounds that keep a solution's pH constant when acids or bases are added.
calcium tetany (TET-ah-nee)
intermittent spasm of the extremities due to nervous and muscular excitability caused by low blood calcium concentrations.
ions (EYE-uns)
atoms or molecules that have gained or lost electrons and therefore have electrical charges. Examples include the positively charged sodium ion (Na+) and the negatively charged chloride ion (Cl-). For a closer look at ions, see Appendix B.
obligatory (ah-BLIG-ah-TORE-ee) water excretion
the minimum amount of water the body has to excrete each day to dispose of its wastes—about 500 mL (about 2 cups, or 1 pint).
calcium
the most abundant mineral in the body; found primarily in the body's bones and teeth.
osmosis
the movement of water across a membrane toward the side where the solutes are more concentrated.
dolomite
a compound of minerals (calcium magnesium carbonate) found in limestone and marble. Dolomite is powdered and is sold as a calcium-magnesium supplement. However, it may be contaminated with toxic minerals, is not well absorbed, and interacts adversely with absorption of other essential minerals.
carbonic acid
a compound with the formula H2CO3 that results from the combination of carbon dioxide (CO2) and water (H2O); of particular importance in maintaining the body's acid-base balance.
thirst
a conscious desire to drink.
hyponatremia (HIGH-po-na-TREE-me-ah)
a decreased concentration of sodium in the blood. caused by excessive sodium losses, not from inadequate sodium intake.
osteoporosis
a disease characterized by porous and fragile bones.
osteoporosis (OS-tee-oh-pore-OH-sis)
a disease in which the bones become porous and fragile due to a loss of minerals; also called adult bone loss.
Magnesium
Catalyst for ATP information
hydroxyapatite
Crystalline structure of bone
Renin
Enzyme released by kidneys
interstitial fluid (IN-ter-STISH-al)
Fluid between the cells (intercellular), usually high in sodium and chloride. -------- is a large component of extracellular fluid.
Sulfur
Mineral that accounts for the structure of many proteins
Calcium
Most prevalent major mineral in the body
Intake and excretion are equal.
Normally, what is the relationship of the amount of sodium excreted to the amount ingested that day?
Aldosterone
Stimulates retention of sodium by kidneys
Antidiuretic hormone
Stimulates retention of water by kidneys
parathyroid hormone
a hormone from the ----- glands that regulates blood calcium by raising it when levels fall too low; also known as parathormone (PAIR-ah-THOR-moan).
Vitamin D
Substance that enhances absorption of calcium
Oxalate
Substance that inhinbits absorption of calcium
1500
The American Heart Association goal is to lower blood pressure by reducing daily sodium intake to less than
angiotensin II
a hormone involved in blood pressure regulation.
Magnesium
The mineral ____________________ forms part of the protein-making machinery and is necessary for energy metabolism.
Average intakes from food are below recommendations.
Which of the following is a feature of magnesium in nutrition?
It has virtually no effect on blood calcium levels
Which of the following is a feature of osteoporosis?
Dietary deficiencies are virtually unknown
Which of the following is a feature of phosphorus in nutrition?
Liberal intakes may correct hypertension.
Which of the following is a feature of potassium?
When a food is burned, all the minerals are found in the ash
Which of the following is a general property of the minerals?
Muscle weakness
Which of the following is a symptom of potassium deficiency?
Potassium
___________________ is the major cation of the intracellular fluids.
hypothalamus
a brain center that controls activities such as maintenance of water balance, regulation of body temperature, and control of appetite.
calmodulin (cal-MOD-you-lin)
a calcium-binding protein that regulates such cell activities as muscle contractions.
magnesium
a cation within the body's cells, active in many enzyme systems.
salt sensitivity
a characteristic of individuals who respond to a high salt intake with an increase in blood pressure or to a low salt intake with a decrease in blood pressure.
salt
a compound composed of a positive ion other than H+ and a negative ion other than OH-. An example is sodium chloride (Na+ Cl-).
Parathyroid hormone
hormone that helps regulate calcium balance
antidiuretic hormone (ADH
a hormone produced by the pituitary gland in response to dehydration (or a high sodium concentration in the blood) that stimulates the kidneys to reabsorb more water and a high sodium concentration in the blood that stimulates the kidneys to reabsorb more water and therefore to excrete less. In addition to its -------- effect, ADH elevates blood pressure and sois also called vasopressin (VAS-oh-PRES-in).
aldosterone (al-DOS-ter-own)
a hormone secreted by the adrenal glands that regulates blood pressure by increasing the reabsorption of sodium by the kidneys. ------- also regulates chloride and potassium concentrations.
calcitonin (KAL-seh-TOE-nin)
a hormone secreted by the thyroid gland that regulates blood calcium by lowering it when levels rise too high.
phosphorus
a major mineral found mostly in the body's bones and teeth. It is involved in energy exchange
bone density
a measure of bone strength. When minerals fill the bone matrix (making it dense), they give it strength.
sulfur
a mineral present in the body as part of some proteins.
oyster shell
a product made from the powdered shells of oysters that is sold as a calcium supplement, but it is not well absorbed by the digestive system.
calcium-binding protein
a protein in the intestinal cells, made with the help of vitamin D, that facilitates calcium absorption.
sulfate
a salt produced from the oxidation of sulfur.
vasoconstrictor (VAS-oh-kon-STRIK-tor)
a substance that constricts or narrows the blood vessels.
bicarbonate
an alkaline compound with the formula HCO3 that is produced in all cell fluids from the dissociation of carbonic acid to help maintain the body's acid-base balance. Bicarbonate is also secreted from the pancreas as part of the pancreatic juice.
renin (REN-in)
an enzyme from the kidneys that hydrolyzes the protein angiotensinogen to angiotensin I. Which results in the kidneys reabsorbing sodium. Cells in the kidneys respond to low blood pressure by releasing an enzyme called -------.
angiotensin I (AN-gee-oh-TEN-sin)
an inactive precursor that is converted by an enzyme to yield active angiotensin II. In addition to its role in sodium retention, renin hydrolyzes a protein from the liver called angiotensinogen to angiotensin I. Angiotensin I is inactive until another enzyme converts it to its active form—angiotensin II. Angiotensin II is a powerful vasoconstrictor that narrows the diameters of blood vessels, thereby raising the blood pressure.
bone meal or powdered bone
crushed or ground bone preparations intended to supply calcium to the diet. Calcium from bone is not well absorbed and is often contaminated with toxic minerals such as arsenic, mercury, lead, and cadmium.
hydroxyapatite (high-drox-ee-APP-ah-tite)
crystals made of calcium and phosphorus. The calcium-rich crystalline structure of teeth and bones
bottled water
drinking water sold in bottles.
major minerals
essential mineral nutrients the human body requires in relatively large amounts (greater than 100 milligrams per day); sometimes called macrominerals.
trace minerals
essential mineral nutrients the human body requires in relatively small amounts (less than 100 milligrams per day); sometimes called microminerals.
extracellular fluid
fluid outside the cells. ----- fluid includes two main components—the interstitial fluid between cells and the intravascular fluid of plasma. ------ accounts for approximately one-third of the body's water.
intracellular fluid
fluid within the cells, usually high in potassium and phosphate. ------- fluid accounts for approximately two-thirds of the body's water.
adrenal glands
glands adjacent to, and just above, each kidney.
calcium rigor
hardness or stiffness of the muscles caused by high blood calcium concentrations.
antacids
medications used to relieve indigestion by neutralizing acid in the stomach. Calcium-containing preparations (such as Tums) contain available calcium. Antacids with aluminum or magnesium hydroxides (such as Rolaids) can accelerate calcium losses.
anions (AN-eye-uns)
negatively charged ions.
dissociates (dis-SO-see-aites)
physically separates.
cations (CAT-eye-uns)
positively charged ions.
electrolytes
salts that dissolve in water and dissociate into charged particles called ions.
electrolyte solutions
solutions that can conduct electricity.
oral rehydration therapy (ORT)
the administration of a simple solution of sugar, salt, and water, taken by mouth, to treat dehydration caused by diarrhea.
osmotic pressure
the amount of pressure needed to prevent the movement of water across a membrane.
water balance
the balance between water intake and output (losses).
milliequivalents per liter (mEq/L)
the concentration of electrolytes in a volume of solution. Milliequivalents reveal characteristics about the solution that are not evident when the concentration is expressed in terms of weight.
dehydration
the condition in which body water output exceeds water input. Symptoms include thirst, dry skin and mucous membranes, rapid heartbeat, low blood pressure, and weakness.
peak bone mass
the highest attainable bone density for an individual, developed during the first three decades of life.
trabecular bone (tra-BECK-you-lar)
the lacy inner structure of calcium crystals that supports the bone's structure and provides a calcium storage bank.
chloride (KLO-ride)
the major anion in the extracellular fluids of the body. ---- is the ionic form of chlorine, Cl-.