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Chapter 12: Minerals

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What Are Minerals?

Inorganic elements essential to the nutrition of humans

Fourteen minerals are essential to body function• Play several key roles in overall health and well

being- Help chemical reactions take place in cells- Help muscles contract- Keep the heart beating

Two groups• Major minerals• Trace minerals

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What Are 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

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What Are Minerals?

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

Figure 12.1

The Minerals in Your Body

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Minerals

Do not contain carbon Contain only atoms of the same element Are most often found

• As individual ions

• In organic compounds

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Minerals

Remain intact during digestion Generally do not change shape or structure when

performing biological functions Most minerals absorbed from the diet are in the form

of water-soluble salts Are not destroyed by heat, acid, oxygen, or ultraviolet

light Mineral bioavailability: Degree to which a nutrient

from food is absorbed and utilized in the body

Mineral Bioavailability

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Mineral Balance

Body maintains tight control over mineral balance

• GI tract

Regulates absorption from food based on the body’s need

Minerals in gastric juices and that slough-off intestinal cells are either excreted in the feces or reabsorbed through the large intestine

• Kidneys

Excretes excess and reabsorbs the minerals when the body needs them

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Mineral Functions

Minerals work together to perform important functions in the body

• Fluid and electrolyte balance

• Blood formation

• Building healthy bones

• Maintaining a healthy immune system

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Minerals Help Maintain Fluid Balance

Minerals play a key role in fluid balance in the cells

• Extracellular minerals – sodium and chloride

• Intracellular mineral – potassium with the help of calcium, magnesium, and sulfur

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Mineral Participate as Cofactors

Cofactor – substance that helps catalyze a reaction Minerals serve as cofactors in

• Antioxidant systems

• Energy production

• Muscle contraction

• Nerve transmission

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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

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Minerals Can Be Toxic

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 dietary intake

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Quick Review

Minerals• Inorganic nutrients • Are classified as either major or trace base on amount

found in the body and the amount needed daily• Bioavailability is based on nutritional status and

mineral binding• Play a vital role in numerous body functions

- Bone and blood health- Fluid balance- Cofactors in energy production and muscle

contraction- Nerve transmission

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Quick Review Continued

Mineral toxicity

• Rare

- Most people do not ingest overly high amount from food

- Body adjusts absorption and excretion

• Occurs with ingestion of high doses of supplements