Minerals provide structure (e.g. bones, teeth), help functioning (e.g. muscular contractility, neural conductivity) and aid regulation (e.g. components of enzymes) of cellular metabolism.

Research has shown that mineral supplementation for a person involved in exercising is not necessary under normal conditions. However, in cases where excessive amounts of sweat have been lost then stores of calcium, potassium and magnesium can be reduced. A glass of orange or tomato juice easily replaces these minerals, important to neural transmission, and bone structure. Research has also indicated that iron deficiencies can rapidly occur in chronic aerobic exercisers and menstrual woman. Iron rich foods such as green vegetables and red meat should be included in the diet.

Major Minerals

Mineral	Main Function	Main Sources	Deficiency	Excess
Calcium	Formation and maintenance of bones and teeth. Blood clotting and nerve function	Milk, cheese, yogurt and canned fish are rich sources. Also dark green leafy vegetables, white and brown flour and bread	Bone weakening- rickets and osteomalacia. This is also due to failure to absorb calcium owing to vitamin D deficiency	Not known in adults
Sodium	Regulation of body water content. Nerve function	Salt - either added to foods during processing or at home in cooking or at the table	Fatigue, nausea, cramps. Thirst is experienced	Excess sodium has been linked to hypertension (high blood pressure)
Potassium	Functioning of cells. Constituent of body fluids	All foods except sugars, fats and oils. Unprocessed foods contain more than processed foods	Weakness, mental confusion and, if extreme, heart failure	Excess is dangerous especially if the kidneys are not functioning properly
Magnesium	Involved in energy transfer in the cell, in enzyme activity and muscle functioning	Widespread but wholegrain cereals, nuts and spinach are good sources	Depression, irritability, fits, tiredness and, if extreme, heart attack	Excess magnesium is not absorbed
Phosphorus	Essential component of all cells and present in bones and teeth	Good sources are milk, cheese, meat, fish and eggs	Dietary deficiency unknown	Not known in adults

Not needed in as large amounts as the major minerals, the trace minerals iron, flourine, zinc, copper, selenium, iodine and chromium are still important in the diet. Of these probably the most easily relatable to sports and exercise is iron (found in eggs, lean meats, legumes, whole grains and green leafy vegetables) which is needed as a constituent of haemoglobin and some of the energy metabolism enzymes.