Minerals are important nutrients found in foods. Alone, they are inactive chemical elements, whether in a rock as calcium or in a cast iron pan. But in the body they become operational, either structurally as bone, for example, or functionally as an electrolyte or hormone. Minerals are the most permanent part of a living organism, responsible for muscle responses, the transmission of messages through the nervous system, the maintenance of pH and the metabolism of food. Because the body is unable to manufacture them, minerals must come from the diet.
There are two groups of minerals in the body, major minerals and trace minerals. The former are required in amounts of 100 milligrams a day or more; the latter in lesser amounts. Different charts from different sources may disagree about some of them, but calcium, phosphorus, magnesium, sodium, chloride and potassium are generally listed as major, while iron, iodine, selenium, zinc, chromium, copper and manganese are often named as trace minerals. This group may also include molybdenum, silicon, boron, cobalt, sulfur and a few others. Each of these, both major and trace, has a specific job to do, and none is less important than any other.
In the body, some of these work as a team. Sodium and potassium work together in muscle contractions and relaxation. Calcium and magnesium have a similar working relationship, but each also does something else. The balance of these teams of minerals will be addressed separately later on. What’s important to realize is that mineral depletion of the soil affects food value and ultimately, our health. Even though minerals move up the food chain from plant to animal to humans, deficiency is more common than imagined. Failure to rotate crops, breeding high-yield nutritionally-shallow cultivars, harvesting prematurely to prevent decay in transit, use of biocides, poor storage and handling, and careless cooking practices combine to denigrate food quality. In 2004, Dr. Donald Davis led a crop nutrient study at the University of Texas Biochemical Institute, tracking the change in food quality of forty-three garden crops over the past few decades, finding statistically reliable declines. (Davis, 2004)
Dietary minerals are present in the human body at a certain mass and concentration necessary to support the biochemical reactions of metabolism dependent upon those minerals. Intake of these is mandatory for optimal health. Deplorably, food cannot provide the necessities. If we consider food insecurity, pitiful dietary choices, chronic illness, injury, imprudent lifestyle or other deviance, a need for mineral supplementation emerges.
If unbalanced beyond the body’s ability to regulate them, minerals can accumulate and cause harm. It’s not a good idea to take minerals merely because there was an advertisement in a popular magazine. For example, selenium is a recognized anti-oxidant mineral. Too much selenium, as might come from regularly eating too many Brazil nuts, can cause fingernails to flake and hair to fall out, garlic breath, pulmonary edema and even cirrhosis. Healthcare professionals, dietitians paramount, will probably dissuade you from taking more than you actually need. Minerals get spent at different rates as they metabolize.
Yes, calcium is needed for bones and a strong heartbeat, but overload can precipitate as kidney stones and cause constipation. Even with perfect foods, diet supplies less calcium than what we need (Ervin, 2004). Chloride helps to make stomach acid and to maintain pH. Deficiency is almost unheard of. Magnesium deficit, however, is real, especially in children who avoid vegetables and because of mindless cooking techniques. Magnesium is a muscle relaxant and a part of more than three hundred enzymes, although most is in bones and teeth. Magnesium overdose can keep you close to the porcelain.
Phosphorus is found in every cell of the body, second in amount only to calcium. It’s part of DNA, contributes to bone and teeth structure, and catalyzes the B-vitamins. Deficiency is unlikely, but overabundance, such as might come from too many cans of soda, can create calcium imbalance. Potassium is an essential electrolyte. Living inside the cell, it controls water and acid-base balance while helping to relax a muscle contraction and to regulate heartbeat. Deficiency is common among the elderly, who are more apt to suffer chronic disease and to take medications that deplete this mineral. Sodium maintains fluid balance and plays a role in muscle contraction, opposite potassium. Diarrhea, vomiting, heavy sweating and chronic illness can compromise sodium stores, but excess is more common.
Chromium enhances insulin function. Cobalt is part of vitamin B12. Copper helps to make collagen and hemoglobin. Iodine keeps the thyroid healthy and helps to regulate energy production. Iron helps to manufacture hemoglobin, and may even benefit the immune system. Manganese supports enzyme reactions and the overall health of the nervous system. Molybdenum helps the body to use iron and to burn carbohydrates. Sulfur, found in all cells and tissues, is needed to make collagen and for the synthesis of proteins. Finally, at least for now, zinc is one of the more active minerals, involved in more than 200 enzymatic reactions. It is essential for growth and development, the regulation of insulin, immune function, prostate health and cell membrane integrity. Imbalance can interfere with copper function.
You may be wondering why silver is absent. It plays no natural biological role in humans, and its health effects are hotly disputed, though topical application for wound healing is less so. Ingested silver may cause argyria, resulting in bluish-gray skin and mucous membranes. Fluorine likewise is not essential, though it is present in tea in varying amounts. Topically on teeth, not internally, is okay.
Mineral deficiencies are not spontaneous. Toxicity may occur inadvertently, as from exposure to industrial pollutants, household chemicals or even some drugs. Iron poisoning is the most common mineral toxicity found in children, almost always resulting from overindulgence in vitamins. With mineral supplementation, prudence is the catchword.
Behall KM, Scholfield DJ, Lee K, Powell AS, Moser PB. Mineral balance in adult men: effect of four refined fibers. Am J Clin Nutr. 1987 Aug;46(2):307-14.
Bushinsky DA. Acid-base imbalance and the skeleton. Eur J Nutr. 2001 Oct;40(5):238-44.
Davis DR, Epp MD, Riordan HD. Changes in USDA food composition data for 43 garden crops, 1950 to 1999. J Am Coll Nutr. 2004 Dec;23(6):669-82.
Ervin RB, Wang C-Y, Wright JD, Kennedy-Stephenson J. Dietary intake of selected minerals for the United States population: 1999-2000. Advance Data from Vital and Health Statistics, number 341. Hyattsville, MD: National Center for Health Statistics, 2004
Daniel König, Klaus Muser, Hans-Hermann Dickhuth, Aloys Berg and Peter Deibert Effect of a supplement rich in alkaline minerals on acid-base balance in humans Nutrition Journal. 10 June 2009; 8:23
Motil KJ, Altchuler SI, Grand RJ. Mineral balance during nutritional supplementation in adolescents with Crohn disease and growth failure. J Pediatr. 1985 Sep;107(3):473-9.
Nielsen FH, Milne DB, Gallagher S, Johnson L, Hoverson B. Moderate magnesium deprivation results in calcium retention and altered potassium and phosphorus excretion by postmenopausal women. Magnes Res. 2007 Mar;20(1):19-31.
Office of Dietary Supplements http://ods.od.nih.gov/
Sebastian A, Harris ST, Ottaway JH, Todd KM, Morris RC Jr. Improved mineral balance and skeletal metabolism in postmenopausal women treated with potassium bicarbonate. N Engl J Med. 1994 Jun 23;330(25):1776-81.
Tucker KL, Hannan MT, Chen H, Cupples LA, Wilson PW, Kiel DP. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women. Am J Clin Nutr. 1999 Apr;69(4):727-36.