You woke up feeling great. You hit the gym early. Today was the day for your most brutal training session ever.
But something went wrong. You added 10 pounds on your bench and failed at the sticking point. Getting through those extra reps was extra hard. After your shower, your muscles still ached. Instead of feeling exhilarated, you felt tired and discouraged that you didn't meet your goals.
It could have been just an off day, but it could be something else. Maybe something's missing from your training diet. Trace elements are the "micronutrients" your body requires in very small doses. They help your heart to beat, your muscles to grow. Without them, your body won't function properly. And it's easy to miss out on one or more vital trace elements, even if you're careful to eat a "balanced" diet.
Much has been written about the importance of the dietary minerals calcium potassium and iron, but it's only recently that researchers have brought to our attention the long-term effects of calcium deficiency, especially in women (osteoporosis). A deficiency of iron takes less time to show itself (anemia), whereas potassium deficiencies show up suddenly and dramatically. Now selenium (once known only as a deadly poison) has been introduced into our health vocabulary. Preliminary studies show that it may protect both animals and humans against some forms of cancer. More and more, scientists are discovering that physical manifestations such as premature aging, baldness, diabetes-type reactions and weakened bone mass may be attributable to a deficiency in one or several of these "micronutrients," They play a subtle part in the body's metabolism, but not because of their caloric value.
The earth's crust is constantly being depleted of these essential minerals both by natural and man-made forces, and foods rich in trace elements are depleted even more by processing. Also, sources such as iodized salt (iodine) and high-cholesterol foods like red meat and eggs (rich in chromium and zinc) are disappearing from our diets. So how can we be sure of getting what we need and in the right balance for optimum health?
The quickest way is to take the right mineral supplement. Here's a list of some of the trace elements and major minerals that should be in your mineral supplement, along with a discussion of why they're important to you:
CALCIUM - Most calcium in the human body is found in the bones and teeth. We now know that our need for calcium extends far beyond our formative years. Twenty percent of an adult's hone calcium (2-3 pounds) is reabsorbed and replaced every year. Calcium participates in all muscle contractions, is vital to the functioning of nerve cells and enzyme activity and is responsible for transmission of impulses from nerves to muscles. Calcium should be combined in a two-to-one ratio with magnesium. Taking in more magnesium than calcium leads to anesthesia, e.g., magnesium concentration is high in hibernating animals.
MAGNESIUM - This essential mineral regulates body heat, the contraction of muscles and the synthesis of body protein. It is necessary for calcium and Vitamin C metabolism as well as for phosphorus, sodium and potassium. It is important for converting blood sugar into energy. If you live in a hard water area, you're getting more magnesium than calcium in your water.
SELENIUM - Until 1956 selenium was listed only as a poison in textbooks, so it came as a surprise when the late Klaus Schwartz discovered it was an essential nutritional factor in preventing the death of liver cells in rats. In further experiments he discovered that sub toxic amounts in the drinking water or diet of breast-cancer prone mice caused a dramatic reduction of tumors. It was later found that in certain areas of the US where the soil (and thus the vegetation) is known to be low in selenium, more women die of breast cancer. It is also believed to protect against heart disease, muscular dystrophy, premature aging and immune incompetence.
There is also much evidence to indicate a relationship between the nutritional need for selenium and that for Vitamin E. Lack of either causes muscular dystrophy in many animals and severe edema (water retention) in chicks. Men appear to have a greater need for selenium, since almost half their body's supply concentrates in the testicles and portions of the seminal ducts adjacent to the prostate gland. This element is also lost in the semen. Scientists believe that Vitamin E acts as an antioxidant for selenium. This element has a wide window of use in that dietary intakes of selenium vary widely throughout the world (28-325 micrograms per day) with no indication of toxicity or deficiency. However, diets containing less than 30 micrograms per day are associated with cardiac degeneration among children living in certain parts of China.
IRON - This is one of the most abundant elements in the earth's crust. Seventy percent of the 3-5 grams of iron present in the human body is located in the red blood cells: in hemoglobin (an oxygen carrier in red blood cells), in myoglobin (a stored form of oxygen in muscles), in transferrin (a principal carrier of iron in blood) and ferritin (mainly a storage form of iron). Once in the body, it is carefully conserved, and the 9 billion red blood cells broken down daily yield 20-25 mg of iron, which is all reused or stored. There are many excellent food sources for iron — liver (especially pork), egg yolks and beef. Unfortunately, these foods are also high in cholesterol and should be eaten sparingly.
Some nutritional studies have found that vegetarians have no more iron-deficiency anemia than meat eaters. One possible explanation for this is that Vitamin C enhances absorption of iron in foods and vegetarians often consume more Vitamin C than meat eaters. In addition to Vitamin C, copper, cobalt (found in Vitamin B12), and manganese are necessary to assimilate iron. Iron is necessary for proper metabolism of B vitamins.
CHROMIUM - In 1959 it was established that animals deficient in chromium grow poorly and have a reduced lifespan. These animals also showed a low glucose tolerance, a response similar to a diabetic's insulin deficiency. The American diet contains only small quantities of chromium, according to one study, and that is poorly absorbed. This may reflect our taste for refined foods. Food processing and refining remove up to 80% of chromium from some foods. Unrefined cereals, grains, fats and sugar are good chromium sources. Chromium deficiency is a suspected factor in arteriosclerosis and diabetes, especially among the elderly, who retain the lowest amount of chromium. In fact, once past adolescence, our bodies retain less and less chromium as we age. A high carbohydrate intake may predispose an athlete to a deficiency due to urinary excretion of chromium after carbo-loading. Supplements, including chelated zinc, seem to substitute well for deficient chromium.
MANGANESE - This is very important in the regulation of enzymes that are active in the mitochondrion, the 'powerhouse" of the cell, where ATP is produced. Deficiencies can result in ovarian and testicular degeneration, shortening and bowing of legs and other skeletal abnormalities. Manganese is also necessary to form thyroxin, the principal hormone of the thyroid gland. Having the correct balance in your system helps eliminate fatigue, improve memory, reduce nervous irritability and aid in muscle reflexes. Toxicity is rare, except from industrial sources. Large intakes of calcium and phosphorus will inhibit manganese absorption.
ZINC - Excessive sweating can cause a loss of as much as 3 mg of zinc per day. Most foods either lose zinc during processing, or never contain sufficient amounts due to nutrient-poor soil. Also, health conscious people who have reduced their intake of animal products may not be getting enough zinc in vegetable and plant foods, which are lesser sources than animal foods. Zinc governs a wide variety of body functions. Many enzymes that prevent buildup of lactic acid (the 'fatigue acids') in muscles require zinc for their action. It helps in the formation of insulin. It exerts a normalizing effect on the prostate, and is important in the development of all reproductive organs. New studies show its importance in brain function, and there is strong evidence that it's required for the synthesis of DNA. More zinc is needed when protein and phosphorus intakes are high.
COPPER - A strict vegetarian is more likely to be deficient in this mineral than someone who eats meat and shellfish. The adult human body contains about 75 mg and has an approximate daily turnover of 2%. Depending on the dietary source and amount, 25-40% of copper consumed is absorbed. It is essential for the utilization of Vitamin C and for the amino acid tyrosine, the pigmenting factor for hair and skin. Like some other essential trace elements, it is present as an environmental pollutant in cigarettes, birth-control pills and automobile emisions. Other environmental pollutants, such as cadmium, decrease copper absorption. Toxicity is rare, but an excess may cause lower zinc levels, insomnia, hair loss, irregular menses and depression. Severe deficiency can disrupt the building of connective tissue, cause weakened bones and even rupture the heart.
POTASSIUM - Potassium works with sodium to regulate the body's water balance and normalize heart rhythms. It has been suggested that people today may suffer a chronic deficiency of potassium as a result of food processing and boiling of vegetables. Since potassium is lost in sweat, active people should be particularly aware of signs indicating a potassium deficiency, such as frequent muscle cramping. People whose sodium-potassium balance is off will suffer nerve and muscle dysfunction and possibly irregular heartbeats. People who consume large amounts of coffee, alcohol and sugar are likely to have low potassium levels. Also, if blood sugar is low there is not only a loss of potassium, but water retention as well.
IODINE - Two-thirds of the body's iodine is found in the thyroid gland. In ancient Greece, iodine-rich seaweed was used in the cure of goiter, a malfunction of the thyroid gland caused by iodine deficiency. During Napoleon's reign, iodine was discovered by mistake while chemists produced saltpeter from sea kelp to make gunpowder for blockaded France in her battle with Britain. Besides goiter, a deficiency of iodine can produce slow mental reaction, weight gain and energy loss due to thyroid malfunction. Americans who have reduced their salt intake should be careful to supplement their diets with iodine in other forms.
SILICON - If you thought silicon was used only in computer chips, you're probably not alone. It has only recently (1972) been demonstrated that silicon is essential for growth and development of higher animals, especially as it relates to mineralization and calcification of bone tissue. It is present in low amounts in the internal organs of mammals, and makes up 0.01% of the skin, cartilage and ligaments. People on low-silicon diets have skin, bone and arterial damage.
FLUORINE - Has a stabilizing effect on bones and teeth, although too much can discolor the teeth.
COBALT - Vitamin B12 needs cobalt to carry out its biochemical functions. Iron may be antagonistic to cobalt absorption and a proper ratio between them must he maintained.
MOLYBDENUM - This is one of the few heavy elements known to be essential to life. It aids in carbohydrate and fat metabolism and is a vital part of the enzyme responsible for iron utilization as well as those enzymes involved in tissue oxidation. In China, esophageal cancer was found to be highest in areas where molybdenum levels in food and water were lowest. High environmental molybdenum exposure was also associated with a low dental caries (cavities) rate in children.
NICKEL - Animals deficient in this essential trace element display severe tissue damage in liver cells. Chicks deprived of nickel grow poorly and have thickened legs and dermatitis.
VANADIUM - A probable function is its role in the formation of vanadochromes or oxygen carriers, as well as its ability to inhibit cholesterol synthesis and dental caries by stimulating mineralization of the teeth.
TIN - Not known to be an essential nutrient, tin has demonstrated positive growth effects at levels of 0.5-2 parts per million in the diet. It may have a very subtle but important effect on growth in early infancy. Tin doesn't show up in newborn rats immediately after birth, but it becomes detectable a few hours later. It is believed to be present in colostrum, the remarkably nutritious first fluid secreted by mammals for a few days after the birth of their young.
ARSENIC - You probably know this highly toxic metal as a popular murder weapon in mystery stories. But rats who were fed an arsenic-poor diet developed rough fur, fragile red blood cells and enlarged spleens containing too much iron.
As of August 2004, there was conclusive evidence that arsenic, molybdenum and nickel are essential nutrients. The evidence for vanadium is less strong. The practical importance of these elements in nutrition is uncertain, because their metabolism, biological functions and nutritional requirements have not yet been conclusively studied. A severe deficiency of these elements in the typical American diet seems unlikely On the basis of present knowledge, cadmium and tin are probably not essential nutrients.