Food Nutrients
Minerals

Functions of minerals
As important as vitamins are, they can do nothing for you without minerals. Vitamins cannot be assimilated without the aid of minerals. Minerals act as catalysts for many biological reactions within the body, including muscle response, the transmission of messages through the nervous system, the production of hormones, digestion, and the utilization of nutrients in foods. All tissues and internal fluids of our body contain varying quantities of minerals. Minerals are constituents of the bones, teeth, soft tissue, muscle, blood, and nerve cells. They are vital to overall mental and physical well-being.

Source of minerals
Although the body can manufacture a few vitamins, it cannot manufacture a single mineral. All must be provided in the diet or in dietary supplements. Minerals can be divided into two major groups. The macrominerals, calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur, and the microminerals or trace minerals, copper, iodine, iron, manganese, selenium, and zinc.

Required doses of minerals
Minerals are as important as vitamins and we need an even smaller dose of minerals. In states of good health and a well-balanced diet, we can get the vitamins and minerals we need from the food we eat. In states of altered metabolism (including mental and physical stresses, and during or following an illness), though, we may need more amounts of vitamins and minerals as the body's natural processes of healing and repair cannot go forward unless we have enough-sometimes more-of the vitamins and minerals required.

The recommended dietary allowance (RDA):

There may be a misunderstanding of the meaning of RDA. RDA is not the recommended amount of vitamins or minerals to take daily. Rather, it represents the minimum amount required to prevent an overt, frank deficiency-in healthy people with good absorption and the ability to maintain normal nutritional status.

The RDA underestimates the requirements of an organism under stress. It is not a good guide for your nutritional or dietary intake. For vitamin C, for example, the RDA is 60 milligrams a day-just enough to prevent scurvy in a healthy sailor.

The Dietary Reference Intakes (DRIs)

These are a group that includes the following other nutrient measures:

RDAs
Adequate Intakes (AI)
Estimated Average Intakes (EAR)
Tolerable Upper Intakes (UL)
DRIs are slowly becoming the more accepted form for nutrient recommendations. Experts expect that DRIs will take the place of the RDAs in time.

The recommended dietary allowance (RDA) for minerals

g =grams
mg = milligrams (0.001 g)
mcg = micrograms (0.000001g)
IU = International Units
RE = Retinol Equivalent
Alpha TE = alpha Tocopherol equivalent
+ Generally the higher number was reported.
* AI (Adequate Intake) from the new Dietary Reference Intakes, 1997: Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Values have changed from previous RDA.
** RDA (Recommended Dietary Allowance) from the new Dietary Reference Intakes, 1997: Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Values have changed from previous RDA.

Note: remember that the dosage above is prophylactic i.e. it is the minimum that you require per day, to prevent serious deficiency. The therapeutic dose of the nutrient is usually increased considerably, but the toxicity level must be kept in mind.