Chapter 12: Major Minerals

Minerals

Inorganic elements essential to the nutrition of humans
Two groups:
Major minerals
Trace minerals

Major Minerals

Need to consume > 100 milligrams per day
At least 5 grams of the mineral in the body
Calcium, sodium, potassium, chloride, phosphorus, magnesium, and sulfur

Trace Minerals

Need to consume > 20 milligrams per day
The body contains less than 5 grams total
Iron, zinc, copper, selenium, chromium, iodide, manganese, molybdenum, and fluoride

Minerals Contain

Do not contain carbon
Contain only atoms of the same element
Are most often found:
As individual ions
In organic compounds

Mineral Functions

Fluid and electrolyte balance
Blood formation
Building healthy bones
Maintaining a healthy immune system

Maintain Fluid Balance by

Extracellular minerals - sodium and chloride
Intracellular mineral - potassium with the help of calcium, magnesium, and sulfur

Cofactors

Cofactor - substance that helps catalyze a reaction
Minerals serve as cofactors in:
Antioxidant systems
Energy production
Muscle contraction
Nerve transmission

Minerals make up bones and teeth

Minerals make up the crystalline structure (hydroxyapatite) that gives strength to bones and teeth
Major minerals
Calcium, phosphorus, and magnesium
Trace mineral
Flouride

Toxicity

If ingested in high amounts, minerals can be toxic; however, mineral toxicity is rare
Toxicity most often seen with:
Large amounts of supplements
Certain conditions that interfere with the body's adaptive abilities
Toxicity not generally seen from excess

Sodium Chloride

Accounts for 90% of sodium consumed and almost all of chloride consumed
Comprised of ~40% Na+ and ~60% Cl-
1 teaspoon (5 grams) of NaCl is approximately
2 grams Na+
3 grams Cl-

Sodium

major electrolyte and cation
Is found primarily in the blood and extracellular fluid surrounding the cells
The rest of the body's sodium is located:
-On the surface of the hydroxyapatite crystals in the bone
-In the nerve tissue
-In the muscle tissue
-Pla

Chloride

major electrolyte and an ion
Is found primarily in the blood (~88%)
Remainder (~12%) of chloride
As part of hydrochloric acid in the stomach

Sodium and Chloride

When ingested, the bonds dissociate and allow the ions to mix with water
Are absorbed separately
Are excreted separately via
Kidneys
Skin
Feces

Sodium absorbed

small intestine with a small amount excreted in the feces
Blood maintains precise levels

Sodium balance

Maintained by kidneys
a) when sodium blood levels are low, aldosterone is released from the adrenal glands and stimulates the reabsorption of sodium by the kidneys
b) When sodium levels in blood are high, the adrenal glands shut off the secretion of aldos

Sodium functions

-Transmits nerve impulses and participates in muscle contraction
-Preserves food and enhances flavor
-Helps transport some nutrients

Chloride functions

-Assists in the removal of CO2 from blood
-Helps keep blood within normal pH range
-Participates in digestion as part of hydrochloric acid

Chloride daily needs

adults: 2,300 mg/day

Sodium daily needs

minimum need: 180 mg/day
adults: 1,500 mg/day

Sodium excess

High blood pressure
Calcium deficiency osteoporosis
Fluid retention
Weight gain
Stomach ulcers
Stomach cancer
Hypernatermia

Sodium deficiency

Affect fluid balance
Hyponatremia
N/V
Confusion
Loss of energy/fatigue
Muscle weakness, spasms/cramps
Coma

Food sources of Sodium and Chloride

77% comes from canned goods, cured meats, frozen or packaged meals
12% naturally occurs in foods
5% salt added during cooking
6% added at table

Chloride excess

Hyperchloremia with extreme dehydration

Chloride deficiency

Hypochloremia
Diarrhea
Vomiting
Respiratory loss

Hypertension

normal BP 120/80
Uncontrollable factors:
Family history
Aging process
Race
Controllable Factors:
Diet
Alcohol consumption
Body weight
Physical activity

Potassium

Major intracellular cation
Is absorbed in the small intestine
Kidneys maintain balance by excreting excess

Potassium Function

-Helps maintain fluid balance
-Acts as a blood buffer, helping maintain blood pH
-Helps with muscles contraction and nerve impulse conduction
-Help lower high blood pressure
-Causes kidneys to excrete excess sodium
-Helps buffer blood and preserve calcium

Potassium Daily Needs

4,700 mg/day

Potassium Excess

Hyperkalemia
Addison's disease, heart tissue
Adrenal fatigue
Leg pain after prolonged standing/sitting

Potassium Deficiency

Hypokalemia
Increased risk of hypertension, kidney stones, and loss of bone mass

Calcium

Divalent cation
Most abundant mineral in the body
Over 99% of the body's calcium is located in the bones and teeth

Calcium Function

build strong bones and teeth
Cortical bone (compact)
Trabecular bone (spongy) - more sensitive to changes in dietary calcium
Muscle contraction
Nerve transmission
Blood vessel dilation and contraction
Blood clotting
Help lower high blood pressure
Help pro

Calcium daily needs

1,000 to 1,100 mg/day

Calcium excess

hypercalcemia
constipation
interferes with absorption of other minerals

Calcium deficiency

Hypocalcemia
less dense, weakened, brittle bones
increased risk of osteoporosis and bone fractures

Calcium supplements

part of a compound of calcium carbonate and citrate
Consume in doses of 500 mg or less at a time, the maximum dose the body absorb efficiently at one time
Calcium from unrefined oyster shell, bone meal, and dolomite may contain lead and other toxic metals

Phosphorus

Second most abundant mineral in the body
Majority found in bone tissue
Absorbed via the small intestine
Vitamin D enhances bioavailability
Phytate, magnesium, calcium, and aluminum decrease absorption

Phosphorus in blood

When blood levels are low, parathyroid hormone
Stimulates resorption from bone
Stimulates kidney excretion
Excretion
Majority in the urine
Some lost in feces

Functions of Phosphorus

Needed for the formation of bones and teeth
Part of cell membrane structure
Needed during metabolism
Acts as a buffer in acid-base balance
Part of DNA and RNA

Phosphorus Daily Needs

700 mg/day

Phosphorus food sources

Foods from animal sources
Plant seeds
Soft drinks and colas which contain phosphoric acid

Phosphorus excess

Hyperphosphatemia (only an issue with kidney problems, calcification of body tissue)
High intake of phosphorus with low calcium intake can decrease bone mass

Phosphorus deficiency

hypophosphatemia (muscle weakness, bone pain, rickets, confusion, and death)

Magnesium

About 60% is found in bones, 25% in muscles, and the remainder in various cells
Higher dietary intake results in decreased absorption
High-fiber and whole-grain diet, which are high in phytates, lowers absorption
Intestinal absorption and kidney excretion

Magnesium functions

Needed for metabolism
Needed for synthesis of DNA, RNA, and body proteins
Needed for bone metabolism and cell membrane synthesis
Helps muscles function properly
Helps lower blood pressure
May help decrease the risk of type 2 diabetes mellitus

Magnesium daily needs

female: 310-320 mg/d
male: 400-420 mg/day

Magnesium excess

intestinal problems
diarrhea
cramps
nausea

Magnesium deficiency caused by

medications
poorly controlled DM
Alcohol abuse
muscle weakness, seizures, fatigue, depression, and irregular heart beat

Sulfate

found in body as part of other compounds (proteins, thiamin, biotin)
Absorbed throughout the GI tract
About 80% of sulfate eaten is absorbed
Kidneys excrete excess
Found in body tissue as part of keratin (hair, skin, and nails)

Sulfate functions

Makeup amino acids methionine and cysteine
In foods is used to prevent spoilage and discoloration

Sulfate food sources

Foods that contain methionine, cysteine, glutathione, and taurine