Sodium is a very important nutrient required by all humans and is one of the body's electrolytes, which are minerals that the body needs in relatively large amounts. Electrolytes carry an electric charge when dissolved in body fluids such as blood.

The majority of the body’s sodium is located in the blood and in the fluids present around cells.

Sodium helps the body keep fluids in a normal balance, along with another trace element potassium. It also plays a key role in normal nerve and muscle function. Also Read: Potassium: Functions, Food Sources, Deficiency And Toxicity

The body obtains sodium through food and drink and loses it primarily in sweat and urine. Healthy kidneys maintain a consistent level of sodium in the body by adjusting the amount excreted in the urine.

When sodium consumption and loss are not in balance, the total amount of sodium in the body is affected. The amount (concentration) of sodium in the blood may be too low (hyponatremia) or too high (hypernatremia).
sodium functions and food sources


The primary task of sodium in the system is to control and regulate the volume of blood at any instance.

Maintaining Optimal Blood Volume:

The total amount of sodium in the body affects the amount of fluid in the blood (blood volume) and around cells. The body continually monitors blood volume and sodium concentration. When either becomes too high, sensors in the heart, blood vessels, and kidneys detect the increases and stimulate the kidneys to increase sodium excretion, thus returning blood volume to normal.

When blood volume or sodium concentration becomes too low, the sensors trigger mechanisms to increase blood volume. These mechanisms include the kidneys stimulating the adrenal glands to secrete the hormone aldosterone. Aldosterone causes the kidneys to retain sodium and to excrete potassium. When sodium is retained, less urine is produced, eventually causing blood volume to increase.

Another biochemical process by which sodium balance in the blood is preserved is by means of pituitary gland secreting vasopressin or antidiuretic hormone. Vasopressin causes the kidneys to conserve water.

Dietary Sources:

Sodium is basically ingested into the body as salt i.e. sodium chloride, via processed foods and the table salt or iodised salt used in cooking and seasoning.

While only negligible amounts of sodium are absorbed by means of salt used in preparing dishes or flavouring salads, soups, the major proportion of sodium consumed as part of diet actually comes from packaged foods and enriched products.

These comprise bread, pizza, frozen meat, oily and fried fast food, as well as spicy snacks and savouries such as chips, popcorn, crackers, cookies, sauces, dips and ketchup.

The recommended daily intake of sodium for healthy adults is 2,300 mg per day. Adults with high blood pressure should further limit salt quantities to less than 1,500 mg per day.

Deficiency Diseases:

Hyponatremia is a deficiency disease wherein sodium concentrations in the body are very low. A normal blood sodium level is between 135 and 145 milliequivalents per liter (mEq/L). Hyponatremia occurs when the sodium in your blood falls below 135 mEq/L.

Hyponatremia usually develops when the body retains too much fluid, as in the case of heart failure or liver disease. It is very commonly observed in people who drink too many fluids regularly, as well as those on diuretic medicines, to resolve the health issue of kidneys not functioning optimally.

Situations of hyponatremia must be treated at once, by administering appropriate medications and procedures in a hospital setting.

Imbalance In Sodium Levels And Risk Of Hypertension:

As people age, the body is less able to maintain fluid and sodium balance for several reasons, such as:

Unhealthy Diet: Consuming processed, deep-fried foods regularly, as well as snacking often on salted nuts, chips and biscuits.

Decreased Thirst: As people age, they sense thirst less quickly or less intensely and thus may not drink fluids when needed.

Changes In The Kidneys: Aging kidneys may become less able to reclaim water and electrolytes from the urine and as a result, more water may be excreted in the urine.

Less Fluid In The Body: In older people, the body contains less fluid. Only 45% of body weight is fluid in older people, compared with 60% of younger people. This change means that a slight loss of fluid and sodium, as can result from a fever or from not eating and drinking enough, can have more serious consequences in older people.

Inability To Obtain Water: Some older people have physical problems that prevent them from getting something to drink when they are thirsty. Others may have dementia, which may prevent them from realizing they are thirsty or from saying so. These people may have to depend on other people to provide them with water.

Prescription Medications: Many older people take drugs for high blood pressure, diabetes mellitus, or heart disorders that can make the body excrete excess fluid or magnify the ill effects of fluid loss.

The above situations can result in losing fluid or not consuming enough fluid and thus can cause a high sodium level in the blood, also known as hypernatremia and/or dehydration. Hypernatremia is poorly tolerated by older people and can result in hypertension and even lead to death.

Since more sodium is retained in the body, it causes the force between blood vessels to become very high and intense. This invariably leads to increased strain on arteries, heart muscles and causes hypertension or high blood pressure. Also Check Out: 5 Astonishing Supplements That Helps To Regulate Hypertension - Infographic

Hence it is absolutely essential to seek immediate medical treatment if any symptoms of hypernatremia, dehydration or hypertension are noticed in the person. This aids in the recovery of normal heart functions in the patient and ensures complete recovery and good health.