Minerals
Dietary minerals are inorganic chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen that are present in nearly all organic molecules. The term "mineral" is archaic, since the intent is to describe simply the less common elements in the diet. Some are heavier than the four just mentioned, including several metals, which often occur as ions in the body. Some dietitians recommend that these be supplied from foods in which they occur naturally, or at least as complex compounds, or sometimes even from natural inorganic sources (such as calcium carbonate from ground oyster shells). Some minerals are absorbed much more readily in the ionic forms found in such sources. On the other hand, minerals are often artificially added to the diet as supplements; the most famous is likely iodine in iodized salt which prevents goiter.
Macrominerals
Many elements are essential nutrients called dietary minerals. Some have roles as cofactors, while others are electrolytes. Elements with recommended dietary allowance (RDA) greater than 150 mg/day are, in alphabetical order:
Calcium, a common electrolyte, but also needed structurally (for muscle and digestive system health, bone strength, some forms neutralize acidity, provides signaling ions for nerve and membrane functions)
Chloride; electrolyte; see sodium, below
Magnesium, required for processing ATP and related reactions (builds bone, facilitates peristalsis)
Phosphorus, required component of bones; essential for energy processing
Potassium, an electrolyte (heart and nerve functions)
Sodium, an electrolyte; common in food and manufactured beverages, typically as sodium chloride. Excessive sodium consumption can deplete calcium and magnesium, leading to high blood pressure.
Trace minerals
Many elements are required in trace amounts, usually because they play a catalytic role in enzymes.Some trace mineral elements (RDA < 200 mg/day) are, in alphabetical order:
Cobalt required for biosynthesis of vitamin B12 family of coenzymes. Animals cannot biosynthesize B12, and must obtain this cobalt-containing vitamin in their diet.
Copper required component of many redox enzymes, including cytochrome c oxidase
Chromium required for sugar metabolism
Iodine required not only for the biosynthesis of thyroxine but also — it is presumed — for other important organs as breast, stomach, salivary glands, thymus, etc. (see Extrathyroidal iodine); for this reason iodine is needed in larger quantities than others in this list, and sometimes classified with the macrominerals
Iron required for many enzymes, and for hemoglobin and some other proteins
Manganese (processing of oxygen)
Molybdenum required for xanthine oxidase and related oxidases
Selenium required for peroxidase (antioxidant proteins)
Zinc required for several enzymes such as carboxypeptidase, liver alcohol dehydrogenase, and carbonic anhydrase
Vitamins
Vitamins are essential nutrients, necessary in the diet for good health. (Vitamin D is an exception, as it can be synthesized in the skin in the presence of UVB radiation, and many animal species can synthesize vitamin C.) Vitamin deficiencies may result in disease conditions, including goitre, scurvy, osteoporosis, impaired immune system, disorders of cell metabolism, certain forms of cancer, symptoms of premature aging, and poor psychological health, among many others. Excess levels of some vitamins are also dangerous to health. The Food and Nutrition Board of the Institute of Medicine has established Tolerable Upper Intake Levels (ULs) for seven vitamins.