Food fortification is the public health policy of adding micronutrients (essential trace elements and vitamins) to foodstuffs to ensure that minimum dietary requirements are met.

Simple diets based on staple foods with little variation are often deficient in certain nutrients, either because they are not present in sufficient amounts in the soil of a region, or because of the inherent inadequacy of the diet. Addition of micronutrients to staples and condiments can prevent large-scale deficiency diseases in these cases.

Rationale

Several ranges of food supplements are recognised:

• additives which repair a deficit to "normal" levels
• additives which appear to enhance a food
• supplements taken in addition to the normal diet

Many physicians today disagree with the premise that foodstuffs need supplementation, but accept that - for example - added calcium may provide benefit, or that adding folic acid may correct a nutritional deficiency especially in pregnant women.

On a more controversial level, but well founded in scientific basis, is the science of using foods and food supplements to achieve a defined health goal. A common example of this use of food supplements is the extent to which body builders will use amino acid mixtures, vitamins and phytochemicals to enhance natural hormone production, increase muscle and reduce fat.

Moving on from this reasonably accepted usage, there is increasing evidence for the use of food supplements in established medical conditions. This nutritional supplementation using foods as medicine (nutraceuticals) has been effectively used in treating disorders affecting the immune system up to and including cancers. This goes beyond the definition of "food supplement", but should be included for the sake of completeness.