Sodium

A mineral that helps to regulate the body’s water balance and maintain normal heart rhythm and is involved in conduction of nerve impulses and contraction of muscles. The level of sodium in the blood is controlled by the kidneys, which eliminate any excess in the urine. Almost all foods contain sodium naturally or as an ingredient added during processing or cooking. Consequently, deficiency is rare and is usually the result of excessive loss of the mineral through persistent diarrhoea or vomiting, or profuse sweating. Symptoms include weakness, dizziness, and muscle cramps. In severe cases, there may be a drop in blood pressure, leading to confusion, fainting, and palpitations. Treatment is with supplements. In hot climates, sodium supplements may help to prevent heat disorders by compensating for sodium lost through heavy sweating. Excessive sodium intake is thought to be a contributory factor in hypertension. Another adverse effect is fluid retention, which, in severe cases, may cause dizziness and swelling of the legs.