Minerals

More than 18 mineral elements are believed to be essential for mammals. By definition, macrominerals are required by the animal in the diet in larger amounts and microminerals or trace elements in much smaller amounts. All the macrominerals, except sulphur, are described in the text.

There are 7 macrominerals:

There are at least 11 microminerals. The major microminerals are iron, zinc, copper, and selenium.

MINERALS ARE REQUIRED FOR THE MAINTENANCE OF:
Skeletal structure	Calcium Phosphorus Magnesium
Acid base balance Fluid balance	Potassium Sodium Chloride
Cellular function	All
Nerve conduction	Potassium Magnesium
Muscle contraction	Calcium Magnesium Potassium

Individual minerals

CALCIUM AND PHOSPHORUS

Calcium is the most common mineral in the body and phosphorus is the next most common. Calcium and phosphorus serve as structural components of the bones and the teeth.

Calcium is also important as a messenger which mediates the following:

• constriction and dilation of blood vessels
• nerve impulse transmission
• muscle contractions
• secretion of hormones
• blood coagulation
• a co-factor for enzymes

Since calcium participates in so many functions including keeping the heart beating, it is essential to keep the blood level of calcium at a steady level. This explains why, even when the food is quite deficient in calcium it is not reflected in the blood levels. Additional calcium is quickly released from the bones when the levels in the blood drop below a certain point to ensure that enough calcium is present to keep vital functions working.

SODIUM, POTASSIUM AND CHLORIDE

Sodium, potassium and chloride are the major electrolytes in the body water.

Interesting fact

Electrolytes are minerals found naturally in the body that are present as electrically charged particles, or ions. Electrolytes are needed to keep the body's balance of fluids at the proper level.

They are involved in:

• maintaining acid-base balance
• maintaining osmotic balance
• transmitting nerve impulses
• facilitating and transmitting muscle contractions

Many cat foods sold in grocery stores have a very high salt content.

MAGNESIUM

• is a component of bone, enzymes and intracellular fluids
• has influence on neuromuscular transmissions

IRON

Is an essential component of:

• haemoglobin: the oxygen carrying pigment of the blood
• myoglobin: the oxygen carrying pigment of the muscles

ZINC

Zinc is a constituent or activator of more than 200 enzymes, so it is involved in a high number of diverse physiological functions. Some of zinc's primary functions include:

• immunocompetence
• skin and wound healing
• growth
• reproduction

COPPER

Copper is needed for:

• the formation of red blood cells
• normal pigmentation of skin and hair

SELENIUM

Is an essential component of the naturally occurring antioxidant, gluthathione peroxidase, which is present in all body cells.