Major Functions and Food Sources of Electrolytes (Dissolved in Body Fluids)
ELECTROLYTE |
MAJOR FUNCTIONS |
Food sources |
---|---|---|
Cations Sodium (Na+) (Major ion in extracellular fluid [ECF]) |
Maintenance of osmotic pressure; thus, maintains body fluid balance Assists with normal functioning of neurons and muscle cells Essential for buffer system (acid-base balance) |
Table salt, meat, dairy foods, eggs; many processed and preserved foods including bacon, pickles, and ketchup |
Potassium (K+) (Major ion in intracellular fluid [ICF]) |
Maintenance of osmotic pressure; thus, maintains body fluid balance Normal functioning of neurons and muscle cells, including the heart. Essential for buffer system (acid-base balance) |
Dry fruits, nuts, many vegetables, meat |
Calcium (Ca++) |
- Assists with normal functioning of neurons and muscle cells, including the heart - Essential for neurotransmitter release Maintenance of bones; bone formation - Essential for blood clotting |
Milk and other dairy products, broccoli and other green leafy vegetables, sardines |
Magnesium (Mg++) (Mainly in ICF) |
- Assists with normal functioning of neurons and muscle cells, including the heart; required for ATP use; enzyme production - Maintenance and formation of bones |
Green leafy vegetables, legumes, chocolate, peanut butter, whole grains |
Anions Chloride (Cl_) (Mostly in ECF, combined with Na+) |
- Maintenance of osmotic pressure; thus, maintains body fluid balance Essential for buffer system (acid-base balance) - Maintains acidity of gastric juice (stomach acid-HCl) |
- Cheese, milk, fish - An excess of chloride ions is called acidosis. (NaCl = table salt) |
Bicarbonate (HCO3_) (Most important in ICF |
Maintenance of osmotic pressure; thus, maintains body fluid balance Essential for buffer system (acid-base balance) |
- Does not need to be specifically included in the diet. - Excess bicarbonate ions can result from overuse of antacids, such as sodium bicarbonate (NaHCO3, baking soda). The body also can lose acids as a result of illness. An excess of bicarbonate ions is called alkalosis. |
Phosphate (HPO4_) (mostly occurs in ICF) |
- Maintenance of bones and teeth - Assists with normal functioning of nerves and muscle cells - Assists with formation of ATP (adenosine triphosphate); energy storage - Assists with metabolism of nutrients |
Whole grains, milk and other dairy foods, meat, fish, poultry |
Sulfate (SO4 ) Proteins |
Important in protein metabolism; amino acids Maintenance of osmotic pressure; organic acids |
- Protein-rich foods - Meat, fish, legumes, eggs, nuts, dairy products |
Normal Serum Electrolyte Values
Electrolyte |
Serum Value |
---|---|
Cations |
|
Sodium (Na+) |
135 â 145 mEq/L |
Potassium (K+) |
3.5 â 5.0 mEq/L |
Calcium (Ca++) |
4.3 â 5.3 mEq/L (8.9 â 10.1 mg/dL) |
Magnesium (Mg++) |
1.5 â 1.9 mEq/L (1.8 â 2.3 mg/dL) |
Anions |
|
Chloride (Cl-) |
95 â 108 mEq/L |
Bicarbonate (HCO3-) |
22 â 26 mEq/L |
Phosphate (HPO4-, H2PO4-) |
1.7 â 2.6 mEq/L (2.5 â 4.5 mg/dL) |