Element
Function
Sodium


Source

Regulates body water content and electrolyte balance

Needed for the absorption of water and some nutrients from

the gut

Potassium

Essential for water and electrolyte balance and normal
functioning of the cell including nerves
Health
Very small amount in raw food
Added as salt during processing, preparation, 
preservation and serving

High salt foods includes bacon, cheese, yeast 
extract and smoked fish
Present in all food but found richly in fruits
(dried fruits, bananas, berries),leafy green
vegetables (broccoli and spinach), meat, nuts,
seeds and pulses


Calcium



Essential for normal maintenance and function of
o
Nervous, muscular and skeletal systems
o
Cell membrane and capillary permeability
Catalyst in many enzymatic reactions
Essential in many physiological processes as
o
Transmission of nerve impulses
o
Contraction of cardiac, smooth and skeletal muscles
o
Renal function, respiration and coagulation
Several other functions




Sodium‐induced hypertension occurs in about 1/3 of individuals with hypertension
Low sodium diet and excessive perspiration can result in hypernatremia
Sodium deficiency levels can also be caused by vomiting and diarrhea
Milk and dairy products
Fortified cereals
Calcium‐fortified orange juice
Sardines, salmons

Calcium deficiency (hypocalcaemia)
o
Infantile Rickets
o
Adult osteomalacia
o
Osteoporosis
o
Taking high doses of Ca supplements can cause stomach pains and diarrhea
o
Causes of deficiency:
 Inadequate intake of calcium or Vitamin D
 Hypo‐parathyrodism
 Malabsorbtion syndrome
o
Indications:
 Chronic diarrhea
 Hyperphosphatemia
 Hypo‐parathyrodism
 Menopause
 Renal failure
 Vitamin D deficiency
 Muscle cramps
 Osteoporosis
Hypercalcaemia may occur with therapy
o
Anorexia
o
Nausea
o
Vomiting
o
Constipation
o
Can cause:
 Cardiac irregularities
 Delirium
 Coma
o
If hypercalcemia is present in patients taking digoxin, serious cardiac
dysrhythmias can occur
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
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
Magnesium


Phosphorus
Zinc



Widely distributed in foods: meat, fish and
eggs



Essential in metabolic reactions of proteins and carbohydrates

Important for normal tissue growth especially wound repair
Red meat, liver and oysters






Needed for the formation of hemoglobin in red blood cells
which transports oxygen around the body

Structure component of myoglobin and cytochromes
(necessary for energy metabolism)
Some iron exists as hemosiderin (normally found in

macrophages) and ferritin stored in the liver, spleen and bone
marrow
Has important role in immune system

Fluorine
Green leafy vegetables, meats, seafood
Required in high amounts for those with diets
in protein rich food, calcium and phosphorus
Combines with lipids forming phospholipids
Combines with Ca to form hydroxyapatite and Calcium
phosphate
Required for the synthesis of Nucleic acid, ADP, AMP and ATP 
Responsible for cellular energy transfer
Necessary for the development and maintenance of skeletal
system and teeth
Phosphate enzymes regulate cellular metabolism

Iron
Essential in enzyme systems associated with energy
metabolism (has a vital role in glucose metabolism)
Affects synthesis of lipids and proteins
Required for:
o
Nerve physiology (Allows neurologic system to
function properly)
o
Muscle contraction (participates as cofactor in the
breakdown of glucose, fatty acids and amino acids
during energy metabolism)

Formation of strong teeth and protection against dental caries


Non‐heme iron:
o
Primarily found in plant products
o
2‐10% absorption by intestine
Heme iron
o
Primarily found in animal products
o
10‐35% absorption by the intestines
Drinking water, small amount in tea and
saltwater fish
Some areas add fluoride to drinking water
Toothpaste
Hypomagnesaemia
o
Malabsorption
o
Alcoholism
o
Anti‐diuretics
o
Treatment:
 Anti‐convulsant in Magnesium deficiency
 Preeclampsia and eclampsia
Hypermagnesemia
o
Respiratory distress
o
Heart block
o
Hypothermia


Dietary deficiency is rare
Caused by:
o
Malabsorption
o
Extensive diarrhea or vomiting
o
Hepatic disease

Iron deficiency anemia
o
Causes sluggishness, loss of appetite, lack of energy, general weakness and lack
of concentration
Too much iron can cause constipation, nausea and vomiting
Vegetarian diets and anemia:
o
Non‐heme iron has low bioavailability
o
Women on vegetarian diets increase risk for developing iron insufficiency
Both vitamin C and moderate physical activity increase absorption of iron
Sports anemia:
o
Reduced hemoglobin levels approaching clinical anemia as a result of intense
training
o
Hemoglobin becomes diluted due to increase in plasma volume





Excessive intake leads to mottling and discoloration of teeth