Sodium is a mineral that is present only in small quantities in most natural foods, but salt is added, often in large amounts, in food processing and by cooks to enhance flavour. Sodium is the predominant ion in extracellular fluid. An excess of sodium can cause edema, an accumulation of extracellular fluid, especially in conditions such as congestive heart failure. A low sodium intake leads to a lowering of the blood pressure and brings about diuresis, ridding the body of the excess extracellular fluid. Sodium functions with chloride and bicarbonate to maintain a balance of positive and negative ions (electrically charged particles) in our body fluids and tissues. The body receives sodium primarily in the form of table salt (sodium chloride). Sodium, the principal extracellular ion, has the property of holding water in body tissues.

Sodium is vital component of nerves as it stimulates muscle contraction. Sodium also helps to keep calcium and other minerals soluble in the blood, as well as stimulating the adrenal glands. High sodium levels can cause high blood pressure. Sodium aids in preventing heat prostration or sunstroke

Too little sodium in the diet disturbs the tissue-water and acid-base balance that is important to good nutritional status. Sodium mineral is readily absorbed from the small intestine, and normal storage is accomplished by muscle and cartilage tissue. The hormone aldosterone controls the balance of sodium and water in the body. There is now much evidence that excess dietary salt may contribute to high blood pressure in some individuals, but other factors are also responsible.

What is Sodium ?
Sodium is the predominant ion and electrolyte, needed for the blood regulation in the human body. Serious impairment is caused due to the abrupt dysfunctioning of sodium. It is a versatile element and occurs in more than eighty forms. As an electrolyte, it regulates the body fluid and transmits electrical impulse in the body. Unlike minerals and vitamins, heat has no effect on sodium. Thus, it can be used for heat resistive processes. Also, it is an important constituent of nerves and helps in muscle contraction.

Though, sodium is an essential nutrient in the balanced diet, it also causes stomach cancer and hypertension. Those who are suffering from kidney problems and edema should strictly restrict the consummation of sodium in their daily diet.

Thus, sodium is the vital component in the human diet for the correct regulation of cells and nerves in the human body. Supplemental dosage of sodium is necessary during excessive perspiration, sunstroke and adrenal insufficiency. As it is regularly excreted through urine, it does not pose life threatening risks.

Deficiency Symptoms
Recommended intake value of sodium is 120mg/day. But its deficiency can be harmful, as it directly attacks the nervous system of human body. In general, it leads to:
arw Diarrhea
arw Vomiting
arw Headache
arw Weakness
arw Low blood pressure
arw Lethargy
arw Weight loss
arw Confusion
arw Dizziness
arw Muscular irritability

Where it is found
Sodium occurs naturally in most foods. The most common form of sodium is sodium chloride, which is table salt. Milk, beets, and celery also naturally contain sodium, as does drinking water, although the amount varies depending on the source.

Sodium is also added to various food products. Some of these added forms are monosodium glutamate, sodium nitrite, sodium saccharin, baking soda (sodium bicarbonate), and sodium benzoate. These are ingredients in condiments and seasonings such as Worcestershire sauce, soy sauce, onion salt, garlic salt, and bouillon cubes.

Processed meats, such as bacon, sausage, and ham, and canned soups and vegetables are all examples of foods that contain added sodium. Fast foods are generally very high in sodium.

Benefits / uses
Water Balance: Sodium is one of those minerals, which helps to maintain water level in the human body. Sodium and water balance are very interdependent. It pumps water in the cell and regulates the amount of extra cellular fluid in the body.

Sunstroke: It is caused due to the failure of heat regulating system of the human body. This heat exhaustion is caused due to continuous exposure to very high temperature due to which the body loses its capacity to maintain the normal temperature. This condition is further aggravated due to the loss of salt and water from the body. Thus, Sodium plays a vital role in preventing sun stroke or heat prostration by replacing the loss of essential electrolytes. Besides water, drinking fluids containing salt and sugar is favorable against sunstroke. Salt can also be mixed with the drink of raw mangoes to provide more relief. It is very important for ultra endurance athletes.

Brain function: Brain is very sensitive to the change in sodium level of the body, which often leads to confusion and lethargy. Sodium aids in keeping the mind sharp. It is an important element for development of brain. Sodium facilitates the improvement of brain functions.

Muscle cramps: These are caused mostly during the hot summer months, due to electrolyte imbalance and dehydration. Thus, apart from proper hydration of the body, it is also important to supplement one’s body with sodium rich juices and fluids to restore the amount of electrolyte.

Anti aging: Sodium is an important hydrating product of anti-aging creams. It fights with the radicals which accelerate the aging process. It helps in restoring youthful and healthy skin.

Eliminates excess carbon dioxide: Sodium plays an important role in the removal of excess amount of carbon dioxide accumulated in the body.
Maintains glucose absorption: It helps in absorption of glucose by cells for the smooth transportations of nutrients in body cell membranes.
Maintains acid-base balance: By altering proportions of acid-base alkali phosphates it controls reaction of urine in kidneys.
Regulation of fluids: The health benefits of sodium balances the osmotic pressure in the human body due to regulation of fluid in body cells.
Balance of ions: Sodium shares an association with chlorides and bicarbonates in maintaining a sound balance between two types of ions, positively charged ions as well as negatively charged ions.

Maintains healthy condition of the heart: It maintains the contraction of heart. It plays a vital role in maintaining the blood pressure of the human body. Increase in sodium content can dramatically boost the blood pressure.

Dietary sodium is measured in milligrams (mg). Table salt is 40% sodium; 1 teaspoon of table salt contains 2,300 mg of sodium.
Healthy adults should limit sodium intake to 2,300 mg per day while individuals with high blood pressure should consume no more than 1,500 mg per day. Those with congestive heart failure, liver cirrhosis, and kidney disease may need much lower amounts.

Specific recommendations regarding sodium intake do not exist for infants, children, and adolescents. Eating habits and attitudes about food formed during childhood are likely to influence eating habits for life. For this reason, moderate intake of sodium is suggested.

Possible Side effects / Precautions / Possible Interactions:
Too much sodium may lead to high blood pressure in those who are sensitive to sodium. If you have high blood pressure, your doctor will probably recommend that you reduce your sodium (salt) intake.

Sodium may lead to a serious build-up of fluid in people with congestive heart failure, cirrhosis, or kidney disease. Such people should be on a strict sodium-restricted diet, as prescribed by their doctor.

Reference & Research
Lichtenstein AH, et al. AHA Scientific Statement. Diet and lifestyle recommendations revision 2006. A scientific statement from the American Heart Association Nutrition Committee. Circulation. 2006;114:82-96.

arw U.S. Department of Health and Human Services (HSS) and U.S. Department of Agriculture (USDA). Dietary Guidelines for Americans -- 2005.