Electrolyte Balance: Functions of Electrolytes, Sources, RDA, Imbalance, Causes, Symptoms, Treatment

What are Electrolytes?

Electrolytes are chemicals which conduct electricity when mixed with water. They control the function of the nerves and muscles, hydrate the body, balance blood acidity and pressure, and help repair damaged tissues. Muscles and nerves are often referred to as the “electric tissue” of the body. They depend on the movement of electrolytes through fluids inside, outside, or within cells.

The body contains a wide range of ions or electrolytes that perform a number of functions. Some ions aid with the movement of electrical impulses along cell membranes in neurons and muscles. Other ions help stabilize protein structures in enzymes. Still more are helping to release hormones from endocrine glands. Both ions in plasma contribute to the osmotic balance that governs the flow of water between cells and their environment.

Electrolytes in the living system contain sodium, potassium, chloride, bicarbonate, calcium, phosphate, magnesium, copper, zinc, iron, manganese, molybdenum, copper and chromium. Six electrolytes are most essential for body functioning: sodium, potassium, chloride, bicarbonate, calcium and phosphate.

Functions of Electrolytes in the Body

Electrolytes are essential to maintaining a healthy nervous system, muscle functioning and internal environment. Below are some of the most important functions of electrolytes in the body:

• Regulate the Nervous System
• Enhance Contraction and Relaxation of Muscles
• Ensure Proper Hydration
• Regulate Internal pH Levels

Regulate the Nervous System

The brain sends electrical signals through the nerve cells to interact with the cells throughout the body. These signals are called nervous impulses and are produced by changes in the electrical charge of the nerve cell membrane. Changes arise due to the passage of the sodium electrolyte across the nerve cell membrane. As this occurs, it causes a chain reaction that pushes more sodium ions (and changes in charge) along the length of the nerve cell axon.

Enhance Contraction and Relaxation of Muscles

Calcium electrolyte is required for muscle contraction. It helps the muscle fibers to slip together and travel over each other as the muscle shortens and contracts. Magnesium is also needed in this process so that muscle fibers can slide outwards and muscles can relax after contraction.

Ensure Proper Hydration

Water must be held in the right concentrations inside and outside of cell in the body. Electrolytes, particularly sodium, help maintain fluid balance through osmosis. Osmosis is a mechanism in which water passes through the wall of a cell membrane from a dilute solution (more water and less electrolytes) to a more concentrated solution (less water and more electrolytes). This prevents cells from bursting to complete or shriveling due to dehydration.

Regulate Internal pH Levels

In order to remain healthy, the body needs to control its internal pH. pH is a measure of how acidic or alkaline a solution is. It is regulated in the body by chemical buffers or weak acids and bases, which help to reduce changes in the internal environment. For example, blood is controlled to remain at a pH of about 7.35 to 7.45. If it deviates from this, the body cannot function properly, and the person becomes unwell. Getting the right electrolyte balance is necessary for maintaining an optimum blood pH level.

Dietary Sources of Electrolytes

The best way to achieve and maintain electrolyte balance is through a balanced diet. The primary food sources for electrolytes are fruit and vegetables. However, table salt is a natural source of sodium and chloride.

The table below shows some of the foods that include electrolytes:

Recommended Daily Allowance (RDA) of Electrolytes

The ingestion of the correct amount of electrolyte is critical for the maintenance of good health. The average daily allowance (RDA) for some of the most common electrolytes is as follows:

Electrolyte Imbalance

If the electrolyte level in the blood is too high or too low, this leads to an imbalance. Electrolyte levels can change in relation to body water levels as well as other factors. Essential electrolytes, including sodium and potassium, are lost in sweat during exercise. The concentration can also be impaired by a sudden loss of fluids, such as diarrhea or vomiting.

These electrolytes must be replaced in order to maintain safe levels. The concentration of each electrolyte is controlled by the kidneys and many hormones. If the levels of a substance are too high, the kidneys flush it out of the body, and various hormones work to regulate the levels.

The imbalance poses a health risk when the concentration of a certain electrolyte is greater than the body can control. Low electrolyte levels can also affect overall health. The most common imbalances are sodium and potassium.

Causes of Electrolytes Imbalance

Electrolyte imbalance occurs for several reasons, but most common is a result of one or more of the following:

• congestive heart failure
• cancer treatment
• some drugs, such as diuretics
• bulimia
• age, as the kidneys of older adults become less efficient over time
• kidney disease
• not replenishing electrolytes or staying hydrated after exercise
• prolonged periods of vomiting or diarrhea
• poor diet
• severe dehydration
• an imbalance of the acid-base, or the proportion of acids and alkalis in the body

Signs and Symptoms of Electrolytes Imbalance

Symptoms of electrolyte imbalance depend on which electrolyte is out of balance and whether the level of the substance is too high or too low.

A harmful concentration of magnesium, sodium, potassium or calcium may produce one or more of the following symptoms:

• seizures
• numbness
• nervous system disorders
• excessive tiredness
• convulsions
• muscle spasm
• irregular heartbeat
• weakness
• bone disorders
• twitching
• changes in blood pressure
• confusion

Calcium excess may also occur, especially in those with breast cancer, lung cancer, and multiple myeloma. This type of excess is often caused by the destruction of bone tissue.

Signs and symptoms of excess calcium may include:

• stomach pain
• vomiting
• extreme muscle weakness
• thirst
• dry mouth or throat
• total loss of appetite
• coma
• confusion
• constipation
• frequent urination
• irregular heartbeat
• lethargy
• fatigue
• moodiness and irritability
• nausea

Treatment for Electrolyte Imbalance

Treating an electrolyte imbalance involves either restoring levels where they are too low or reducing concentrations that are too high. If the level is too high, the treatment will depend on the cause of the excess. Low levels are usually treated by the addition of the required electrolyte. The treatment type will also depend on the severity of the imbalance. It is sometimes safe for individual electrolyte levels to be replenished over time without ongoing monitoring. However, symptoms can sometimes be serious and a person may need to be hospitalized and monitored during treatment. The most common treatment for electrolyte imbalance are oral rehydration therapy and electrolyte replacement therapy.

Oral Rehydration Therapy

This treatment is used primarily for people suffering from electrolyte deficiency alongside dehydration, usually following severe diarrhea.

The World Health Organization (WHO) has approved a solution to be used in oral rehydration therapy containing:

• 2.6 grams (g) of sodium
• 1.5 g of potassium chloride
• 2.9 g of sodium citrate

These are dissolved in 1 liter (l) of water and given orally.

Electrolyte Replacement Therapy

In more severe cases of electrolyte deficiency, the substance may be administered either orally or by intravenous (IV) drip. Sodium shortages, for example, may be compounded by an infusion of saltwater solution or sodium lactate compound. Excess may occur if the body loses water without losing electrolytes. A solution of water and blood sugar or glucose is given in these cases.