The term micro-nutrients are often applied to the minerals as they are only needed in small amounts in the human body. At least eighteen minerals are of importance in general human nutrition. Plants and animals do not synthesize minerals - thus the term inorganic elements is applied to the minerals. Most minerals have functional roles as important co-enzymes in the body similar to the role played by the vitamins. The absorption of minerals from food results in their becoming a component of the structure of the body - they thus form parts of the cellular structure, they have functions in enzymes, they play roles in hormone interactions, they play a role in the muscles, they form a part of blood and are major components of the skeletal system of the body. All essential minerals in the body can be divided into two groups - those called the macro minerals or the bulk minerals, and those known as the micro minerals or the trace minerals. The main difference between the two being that the macro minerals are needed in higher amounts than are the micro minerals or trace minerals. The minerals calcium - in teeth and bones, magnesium - in enzyme reactions, and phosphorus - in teeth, bones - form the macro mineral group. While metals like zinc - co-factor in enzymes, iron - in hemoglobin and enzymes, copper in enzymes, manganese - in enzymes, chromium - in insulin function, selenium - co-factor, iodine - in a process involving thyroxin hormone, potassium - tissues and enzymes, and boron - in bones form the micro mineral group.
Different parts of the human body and various tissues serve as storage areas for different minerals. Some of the minerals are stored or used in muscular and skeletal tissues; some are used together with the vitamins as components of the body's numerous enzyme systems. To maintain the optimal and proper composition of bones, blood and other tissues, the human body utilizes minerals and vitamins in various functions - for example they act as regulators and structural as vital components in the human body. Normal cellular function is dependent on the presence of specific minerals and vitamins. Human mental and physical well being is also dependent on the presence of optimal amounts of certain minerals in the body at set levels. Some very important biological reactions in the human body are started by minerals. The process of metabolization of vitamins in the body cannot take place without the aid of certain minerals.
A state of deficiency in an essential mineral or a trace element insufficiency is much more likely to affect a person than is a state of vitamin deficiency. Individuals on a low calorie diet, patients on certain types of medications like diuretics, the elderly and women in a term of pregnancy are at an increased risk of suffering from such mineral insufficiencies. A mineral deficiency is also likely to affect vegetarians and people living on crops in areas where the soil is deficient in certain minerals. The content of essential vitamins in most foods is roughly similar in amounts everywhere in the world; the same cannot be said for mineral and trace element content of foods eaten in different parts of the world. Minerals and trace elements may be scare in some regions and abundant in others due to differing geologic conditions. As an example, soils in parts of China and New Zealand are very poor in selenium while the soil of South Dakota is very rich in this element. Consequently, a person may live in some areas, consuming what seems to be an ideal balanced diet and still develop some form of mineral deficiencies or trace element deficiency - such a situation may only be rectified by a change in diet or via supplementation of the missing trace element.
The theory that there is a greater risk for certain types of cancer and heart disease in individuals who suffer from sub-optimal levels of certain minerals in the body or a deficiency in some trace element like selenium is being increasingly supported by evidence garnered from various clinical studies done on human subjects. Factors different from soil mineral depletion can lead to sub-optimal intake of certain minerals and trace elements. Among these diverse factors, examples include the over processing of food stuffs, the effects of acid rain on soil and the excessive refining of food products.
While the human dietary requirement for most of the trace elements and essential minerals are at very miniscule levels, the great vulnerability of the human body to even a minute imbalance in the dietary intake of these minerals can be seen by comparing the total mineral intake of a human being per day - at about 1.5 grams per person, with the total intake of the major energy compounds like the carbohydrates, the proteins and the lipids - at approximately 500 grams per person daily. The average mineral intake comprising just 0.3% of the total consumed nutrients per person belies their importance, in fact, the human body would not be able to utilize the 99.7% of all consumed foodstuffs if essential trace minerals were not consumed as well - this is because most of these minerals have specific roles in many enzyme systems necessary for digestion and regulation of the human body. For example, out of the total nutrients consumed, the mineral zinc forms only 0.003% - however, many biochemical pathways are dependent on the presence of zinc and enzymes may simply be unable to function without this trace element. Thus, a very negative impact on health can result even if just a tiny decrease in the total zinc intake occurs; this adverse reaction can be aggravated if the reduction in the intake of zinc is prolonged.
Some dieticians and certain medical professionals have increasingly discouraged people from consuming more than the Recommended Daily Allowances - RDA's - of any of the trace minerals and vitamins, which they contend is present in sufficient quantities in the typical American diet - this is a contentious issue. This view is challenged by the results of numerous studies and clinical studies which have repeatedly shown, that many Americans and probably most do not get the RDAs for any of the vital minerals and some of the vitamins in the daily dietary intake. Therefore the need for general supplementation of minerals for most people is eminently advisable and practical - barring those affected by a few of the medical conditions where such supplements can prove counterproductive.
The theory that supplementing with minerals or trace elements may aid in preventing different types of cancer, heart disease and even some forms of degenerative disorders is increasingly being supported by more and more evidence from clinical studies on human subjects. Further studies and trials will provide more clues to the importance of these trace elements and more clinical trials need to be conducted in the future. A medical revolution could be on the way as the major impact of well planned supplementation could potentially be of enormous benefit to humanity - as all the evidence garnered till now, still bears out a very positive impact on the use of such supplements.
A last note for the scientific minded reader, while most of these trace elements are often classed under the label of inorganic nutrients, the ultimate delivery form in the diet for some of the inorganic elements are chemical structures where the trace element is bounded to a molecule containing carbon. Such is the case for selenium and chromium.