Minerals

Minerals are categorized based on the amount you need per day. Generally speaking, if you require 100mg or more per day of a certain mineral, it is considered a major mineral. The rest are considered trace minerals. Foods contain and supply us with many minerals, but our bodies vary in their capacity to absorb and use available minerals. Although minerals may be present in foods, they are not bioavailable unless your body can absorb them.

Minerals in the average American’s diet come from both plant and animal sources. Overall, minerals from animal products are absorbed better because binders and fiber are not present to hinder absorption. A diet free of animal products is likely to be marginal in calcium and other minerals. Because bioavailability is in question, a multi-mineral supplement is always a good idea. Vegans should be especially aware of taking a good mineral supplement.

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Sodium (Na)

Natural Sources: Table salt, white bread and rolls, processed meats, cheese, soups, spaghetti, and tomato sauces.

RDA: 2,400mg

Function: Helps regulate water balance in the body, plays a crucial role in maintaining normal blood pressure, aids in muscle contraction and nerve transmission, and regulates the body’s acid-base balance.

Deficiency Symptoms: Muscle and stomach cramps, nausea, fatigue, mental apathy, muscle twitching and cramping, and appetite loss.

Toxicity: Some experts say that adults should limit their intake to 3,000mg per day, but the verdict is still out on toxicity. Approximately 10 to 15% of adults are sodium sensitive and for these people, high sodium intakes can contribute to hypertension.

Fitness Applications: If you are going to be heavily exercising and sweating considerably, be sure to take in some extra sodium before or during exercise for proper electrolyte balance. According to the Gatorade Sport Science Institute, each liter of sweat can contain 1.8 grams of sodium or more, and a loss of just a few grams can affect nerve endings and muscle fibers, which may lead to cramping.

Did You Know? Table salt is 40% sodium and 60% chloride. The range of sodium intakes seen in adults of 3 to 6 grams per day, which translates to 7.5 to 15 grams of salt. A teaspoon of salt contains about 2 grams of sodium.

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Phosphorus (P)

Natural Sources: Milk, cheese, yogurt, bakery products, meat, cereals, bran, eggs, nuts, fish, and soft drinks.

RDA: 700mg

Function: Builds strong bones and teeth; promotes energy metabolism; promotes growth, maintenance, and repair of all body tissues; and buffers body fluids for acid-base balance.

Deficiency Symptoms: Deficiency is very unlikely since phosphorus is widely available and easily absorbed, but symptoms can include bone pain, loss of appetite, weakness, and easily broken bones.

Toxicity: Typical phosphorus intakes do not seem to be toxic. The Tolerable Upper Intake for phosphorus is 3-4 grams per day.

Fitness Applications: No special applications for athletes.

Did You Know? Phosphorus, is the second most abundant element (after calcium) present in our bodies, and makes up about 1% of our total bodyweight.

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Potassium (K)

Natural Sources: Asparagus, avocados, bananas, beans, cantaloupe, carrots, citrus fruit, juices, milk, molasses, nuts, peas, potatoes, raisins, salt substitutes, sardines, spinach, whole-grain cereal, coffee, and tea.

RDA: 3,500mg

Best Source: Potassium chloride is the most common form used in supplements.

Function: Maintains water balance in body tissues and cells; promotes regular heartbeat; promotes normal muscle contraction; regulates transfer of nutrients to cells; preserves or restores normal function of nerve cells, heart cells, skeletal muscle cells, and kidneys.

Deficiency Symptoms: People who exercise heavily may need to replenish their potassium. Symptoms include loss of appetite, muscle cramps, confusion, constipation, and weakness. Eventually these symptoms can lead to low blood pressure and an irregular heartbeat, which can cause cardiac arrest and death.

Toxicity: If the kidneys function normally, typical intakes of potassium are not toxic. When the kidney functions poorly, potassium can build up in the blood, inhibiting heart function.

Fitness Applications: Potassium (along with magnesium) help muscles both contract and relax. When the body is low in potassium muscles can cramp more easily and fatigue can occur quicker.

Did You Know? The intracellular fluids (fluids inside cells) contain 95% of the potassium in the body.

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Calcium (Ca)

Natural Sources: Milk, cheese, leafy green vegetables, broccoli, sardines, canned salmon, fortified juice, breakfast cereals, and tofu.

RDA: 1,000mg

Function: Calcium requires a slightly acidic pH and vitamin D for efficient absorption. Calcium carbonate is the most common form of calcium used in supplements, and it has the highest concentration of calcium by weight (40%) compared to calcium citrate (21%) and calcium phosphate (8%). Calcium carbonate is a good form to take, but calcium citrate may be better due to its acidic properties and enhanced absorption. Remember that calcium citrate has a little less calcium concentration per weight so you will have to take in more total grams than the carbonate form.

Benefits: Builds bones and teeth, maintains bone density and strength1, helps prevent osteoporosis2, assists in blood clotting, important for transmission of nerve impulses to target cells, aids in muscle contraction, and helps regulate metabolism.

Deficiency Symptoms: Frequent fractures, muscle contractions, convulsive seizures, and muscle cramps.

Toxicity: 2,500mg is the Tolerable Upper Intake. Toxicity symptoms can include headache, irritability, kidney failure, kidney stones, and decreased absorption of other minerals.

Fitness Applications: Most athletes need 1,000 -1,500mg per day.

Did You Know? To estimate your calcium intake, use the “300” rule. For a moderate energy intake from typical daily foods, give yourself 300mg. For every cup of milk or yogurt or 1.5 oz of cheese, add another 300mg. From there, you can add any fortified foods or supplements you are taking.

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Magnesium (Mg)

Natural Sources: Almonds, avocados, bananas, bluefish, carp, cod, collards, dairy products, flounder, halibut, herring, leafy green vegetables, shrimp, swordfish, wheat germ, whole-wheat bread, broccoli, beans, nuts, and seeds.

RDA: Women: 310 - 320mg, Men: 400 - 420mg

Function: Aids in nerve and muscle function3, including regulation of normal heart rhythm4; conducts nerve impulses; helps activate ATP; supports optimal hormone balance; contributes to potassium and calcium metabolism; aids in many enzyme reactions; acts as antacid in small doses; strengthens tooth enamel; and contributes to bone health.

Deficiency Symptoms: Muscle contractions or pain, convulsions, confusion, concentration difficulties, irregular heartbeat, irritability, nervousness, and skin problems.

Toxicity: The Tolerable Upper Intake for supplements above and beyond what food sources supply is 350mg. Toxicity is of higher concern to those people with compromised kidney function because the kidneys primarily regulate blood magnesium. High blood magnesium can lead to weakness, nausea, and depression.

Fitness Applications: The average man consumes about 350mg of magnesium per day, 50mg below the RDA.5 Vitamin D enhances magnesium absorption. To help ensure adequate intake of magnesium and support optimal hormone balance, including testosterone, try EAS’ ZMA™ HP.

Did You Know? A link between magnesium deficiency and sudden heart attacks has been observed. Now, an intravenous dose is being investigated as part of the treatment during the early phases of a heart attack.

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Chromium (Cr)

Natural Sources: Beef, brewer’s yeast, calf liver, cheese, chicken, egg yolks, molasses, sweet potatoes, tomatoes, whole-grain products, mushrooms, and nuts.

RDA: 120 mcg (micrograms)

Function: Promotes glucose metabolism6, helps insulin regulate blood sugar, decreases insulin requirements and improves glucose tolerance of some people with type II diabetes, and aids in protein synthesis.

Deficiency Symptoms: Impaired glucose tolerance, and elevated blood cholesterol and triglycerides.

Toxicity: Based on average intake levels of chromium, toxicity is unlikely. However, there may be some concern of long-term high intake. Because chromium is a metal, it may accumulate in the body with extended use. Some toxicity has been reported in people exposed to chromium in industrial settings. Liver damage and lung cancer may result from such high intakes.

Fitness Applications: Chromium supplementation has been reported to improve glucose metabolism, improve blood lipid concentrations, and reduce bodyfat. However, current research clearly indicates that chromium provides no benefits to healthy individuals.11,12, 13 I do not recommend supplementing chromium as part of your diet or weight-loss efforts.

Did You Know? The amount of chromium in foods is closely tied to the local soil content of chromium. To ensure a sufficient chromium intake, regularly choose whole grains over refined grains.

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Copper (Cu)

Natural Sources: Organ meats, avocados, legumes, lentils, liver, lobster, nuts, oats, oysters, peanuts, raisins, salmon, shell fish, soybeans, spinach, whole-grain breads, and cereals.

RDA: 2mg

Function: Copper promotes normal red blood cell formation, acts as a catalyst in storage and release of iron to form hemoglobin for red blood cells. It assists in

the production of several enzymes involved in respiration, assists in production of several enzymes involved in forming melanin, promotes normal insulin function, and helps maintain connective tissue and myelin (the insulation material around nerves).

Deficiency Symptoms: Anemia, which is low red-blood cell count associated with reduced resistance to infection; faulty collagen formation; bone demineralization; and loss of hair or skin pigmentation.

Toxicity: Dietary copper is not toxic because intakes are usually low and our bodies can regulate storage through excretion. At single supplemental dosages of 10 -15mg, copper tends to cause vomiting.

Fitness Applications: No special applications.

Did You Know? Use of large doses of antacids may bind enough copper in the intestine to cause a deficiency.

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Iodine (I2)

Natural Sources: Iodized salt, saltwater fish, seafood, molasses, and some plants grown near the sea.

RDA: 150 mcg

Function: Supports hormone synthesis in the thyroid gland and prevents goiter (an enlargement of the thyroid gland).

Deficiency Symptoms: Goiter, which is the insufficient function of the thyroid gland, and leads to a fall in metabolic rate and an increase in blood cholesterol. In children, a deficiency can cause depressed growth, delayed sexual development, mental retardation, and deafness.

Toxicity: Iodine intakes up to 2mg per day appear to be safe. However, when very high amounts of iodine are consumed, thyroid hormone synthesis is inhibited (same as a deficiency). A “toxic goiter” results.

Fitness Applications: No special recommendations.

Did You Know? Some areas of Europe have yet to adopt the practice of fortifying salt with iodide. People in these areas still suffer from goiter. In fact, about 1 billion people worldwide are at risk of iodine deficiency, and approximately 20% of these people have goiter.

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Iron (Fe)

Natural Sources: Meat, spinach, oysters, liver, peas, legumes, bakery products, bread, and crackers.

Iron that is part of hemoglobin and myoglobin molecules in animal flesh is called heme iron. Elemental iron found in plant foods is called nonheme iron.

RDA: Men: 10mg, Women: 15mg

Best Source: Ferrous sulfate to cure iron-deficiency anemia.

Function: Prevents and treats iron-deficiency anemia due to dietary iron deficiency or other causes7, stimulates bone-marrow production of hemoglobin (the red blood cell pigment that carries oxygen to body cells), forms part of several enzymes and proteins in the body, and supports immune function.

Deficiency Symptoms: Listlessness, heart palpitations upon exertion, inadequate temperature regulation, loss of appetite, fatigue, irritability, pale appearance to skin, brittle nails, decreased mental capacity, and learning deficit.

Toxicity: 150 - 200mg per day for 4 to 6 months is usually the treatment for deficiency, so high amounts can be tolerated. However, they should not be continued for an extended period of time. Severe toxicity can lead to organ damage, especially in the liver and heart, diabetes, and bronze skin pigmentation.

Fitness Applications: Athletes should be especially aware of their iron intake, as they can lose a significant amount through perspiration which can lead to impaired performance.14,15 Female athletes may want to take in even more iron, 18 - 25mg per day.16

Did You Know? A good source of iron is from cooking utensils. When acidic foods such as tomato sauce are cooked in iron cookware, some iron from the pan is taken up by the food. The replacement of iron cookware with stainless steel and aluminum in recent times has likely increased the risk for iron deficiency.

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Manganese (Mn)

Natural Sources: Beans (dried), blue and blackberries, bran, buckwheat, carrots, chestnuts, hazelnuts, oatmeal, peanuts, peas, pecans, seaweed, spinach, tea, and whole grains.

RDA: 2 - 5mg

Function: A co-factor for certain enzymes, it aids in carbohydrate metabolism and the formation of connective tissue and bones, promotes nerve function, and it’s involved in antioxidant processes.

Deficiency Symptoms: Deficiency in adults is highly unlikely, and symptoms have not been observed in adult humans. Deficiency in children can lead to abnormal growth and development.

Toxicity: Toxicity is also highly unlikely, as average intakes fall within the RDA range. Manganese toxicity has been seen in people who work in manganese mines, and includes severe psychiatric abnormalities, irritability, violence, hallucinations, and impaired control of muscles.

Fitness Applications: No special applications

Did You Know? Consuming high amounts of calcium and phosphorus can inhibit manganese absorption.

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Molybdenum (Mo)

Natural Sources: Milk, milk products, beans, whole grains, and nuts.

RDA: 75 mcg

Function: Necessary for the function of the enzyme xanthine dehydrogenase, which functions in the formation of uric acid and the mobilization of iron from liver stores.

Deficiency Symptoms: No deficiency symptoms have been observed in people consuming a normal diet, though deficiency signs have appeared in malnourished people. These symptoms include increased heart and respiration rates, night blindness, mental confusion, edema, and weakness.

Toxicity: Toxicity has not been established in humans, but lab animals consuming very high dosages of molybdenum have developed evidence of toxicity.

Fitness Applications: No special applications.

Did You Know? High intakes of molybdenum can inhibit copper absorption.

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Selenium (Se)

Natural Sources: Bran, broccoli, brown rice, cabbage, chicken, garlic, kidney, liver, milk, mushrooms, nutritional yeast, oatmeal, onions, seafood, tuna, and whole-grain products

RDA: Men: 70mcg, Women: 55mcg

Benefits: Complements Vitamin E as an efficient antioxidant, plays a role in thyroid hormone metabolism, supports immune system function8, reduces free radical production, and may protect against cancer.

Deficiency Symptoms: Symptoms include muscle pain and muscle wasting. Selenium deficiency has resulted in cardiomyopathy and myocardial deaths in humans.

Toxicity: Daily intakes as low as 1 - 3mg can cause toxicity symptoms if taken for many months. These symptoms include hair loss, nausea, diarrhea, fatigue, and changes in fingernails and toenails.

Fitness Applications: Since selenium is an antioxidant, I recommend 150-250mcg for hard-training athletes to fight free radicals caused by intense exercise.

Did You Know? Much of the selenium present in plant sources is determined by the content of selenium in the soil that they are grown. Northeast China, New Zealand, and Finland have especially low soil concentrations of selenium.

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Zinc (Zn)

Natural Sources: Beef or other red meats, egg yolk, fish, herring, lamb, maple syrup, milk, molasses, oysters, pork, sesame seeds, soybeans, sunflower seeds, turkey, wheat bran, wheat germ, whole-grain products, and yeast.

RDA: 15mg

Benefits: More than 300 enzymes require zinc as a co-factor for optimal activity. It supports synthesis and function of DNA; aids in wound healing, metabolism,

and growth9; essential to normal immune function, ensures development of sexual organs and bone; and supports insulin function.

Deficiency Symptoms: Loss of taste and smell, slow growth in children10, rashes, multiple skin lesions, impaired appetite, hair loss, sterility, low sperm count, and delayed wound healing.

Toxicity: Supplements 5 to 20 times the RDA for extended periods of time can inhibit copper absorption and reduce HDL (good cholesterol). Intakes over 100mg per day can also result in diarrhea, nausea, cramps, vomiting, and depressed immune function.

Fitness Applications: No special applications.

Did You Know? If you’re taking both iron and zinc, make sure to take them at separate times as they interfere with each other's absorption.

References Cited:

1. Chapurlat, R., et al., "Therapeutic strategies for osteoporosis." Ann Med Interne (Paris) 151.6 (2000) : 471-476.

2. Wood, B., et al., "Osteoporosis." J Am Ostoepath Assoc 100.10 (2000) : S9-15.3. Lukaski, H. C. "Magnesium, zinc, and chromium nutriture and physical activity." Am J

Clin Nutr 72.2 (2000) : 585S-93S.4. Seelig, M. G., "Interrelationship of magnesium and congestive heart failure." Wien

Med Wochenschr 150.15-16 (2000) : 335-341.5. Morgan, J. K., et al., “Magnesium and Calcium Dietary Intakes of the US

Population.” J. Am. Coll. Nutr. 4.2 (1985) :195-206.6. Preuss, H. G., et al., "Chromium update: examining recent literature 1997-1998."

Curr opin Clin Nutr Metab Care 1.6 (1998) : 509-512.7. Hindmarsh, O. C. et al., "Effect of early maternal iron stores on placental weight and

structure." Lancet 356.9231 (2000 ): 719-723.8. Rayman, M. P., "The imporance of selenium to human health." Lancet 356.9225

(2000) : 233-241.9. Semrad, C. E. "Zinc and intestinal function." Curr Gastroenterol Rep 1.5 (1999) :

398-403.10. Sayeg Porto, M. A. et al., "Linear growth and zinc supplementation in children with

short stature." J Pediatr Endocrinol Metab 13.8 (2000) : 1121-1128. 11. Lukaski, H.C., “Magnesium, Zinc, and Chromium Nutriture and Physical Activity.” Am

J Clin Nutr 72.2 (2000) : 585S – 93S.12. Amato P., Morales A.J., Yen S.S., “Effects of Chromium Picolinate Supplementation

on Insulin Sensitivity, Serum Lipids, and Body Composition in Healthy, Nonobese, Older Men and Women.” J Gerontol A Biol Sci Med Sci 55.5 (2000) : M260-3.

13. Joseph L.J., et al., “Effect of Resistance Training With or Without Chromium Picolinate Supplementation on Glucose Metabolism in Older Men and Women.” Metabolism 48.5 (1999) : 546-53.

14. Chatard J.C., et al., “Anaemia and Iron Deficiency in Althetes. Practical Recommedations For Treatment.” Sports Med 27.4 (1999) : 229-40.

15. Waller M.F., Haymes E.M., “The Effects of Heat and Exercise on Sweat Iron Loss.” Med Sci Sports Exerc 28.2 (1996) : 197-203.

16. Beard J., Tobin B., “Iron Status and Exercise.” Am J Clin Nutr 72.2 (2000) : 594S-7S.