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Minerals
Minerals come from the earth, the very soil our fruits and vegetables are grown in. Plants absorb minerals as they grow, passing them along to us through the food we eat. Multivitamins and individual dietary supplements can provide for our mineral needs, too, if our diet falls short. Diet almost always takes care of our need for certain minerals - potassium, boron, iodine, manganese and molybdenum - because we need such small amounts of them. Supplementation of these minerals is rarely required and is, in fact, discouraged.
Calcium
Other names: Calcium carbonate, calcium lactate, calcium citrate, calcium gluconate and calcium citrate malate.
Why: Builds and maintains strong teeth and bones, regulates muscle contractions (including normal heartbeat), transmits nerve impulses and monitors cell permeability. Calcium needs phosphorus and vitamin D present to be effective.
How much: AI = 1,000 mg daily for adults under age 50; 1,200 mg daily for adults older than 50. Some experts recommend as much as 1,500 daily for adults with an inflammatory condition.
Deficiency: Contributes to bone loss, tooth loss, muscle cramps and hypertension.
Foods: Milk, yogurt, cheese, ice cream, canned sardines and canned salmon, broccoli, kale, turnip greens and bok choy, plus calcium-fortified orange juice, cereal and soy products.
Supplements: Inflammatory arthritis accelerates bone loss, so getting the optimum intake daily is critical. Diet plus a multivitamin usually isn't enough. Supplement with 500-mg doses one or more times a day with meals. (Exception: calcium citrate, which can be taken with or without food.) Look for calcium with added vitamin D. Avoid supplements containing coral calcium or those with bone meal or dolomite; they may be contaminated with lead. Take separately from iron supplements.
Too much: UL = 2,500 mg. Too much causes loss of appetite, nausea, vomiting, constipation, muscle weakness, abdominal pain, impaired kidney function and stones. High levels also can interfere with magnesium and zinc absorption.
Interactions: Certain diuretics; heart and hypertension medication; some types of tetracycline antibiotics; and tiludronate, used to treat Paget's disease.
Research note: Evidence shows women with high calcium intake gain less weight and body fat than those with low intakes. Scientists think calcium may trigger fat breakdown, while low intake stimulates fat production. Good evidence for a reduced risk of hypertenstion, stroke, premenstrual syndrome, brain and colon cancer; modest evidence for reduced gum disease risk.
Magnesium
Other names: Magnesium chloride, gluconate, oxide, carbonate, aspartate and citrate (supplement forms); magnesium hydroxide (antacid) and magnesium sulfate (Epsom salt).
Why: Maintains muscle and nerve function, keeps heart rhythm regular and strengthens teeth and bones.
How much: RDA = 420 mg for men older than 31; 320 mg for women older than 31.
Deficiency: Low levels linked to high blood pressure, heart attacks, strokes, diabetes, osteoporosis and migraine headaches.
Foods: Artichokes, oatmeal, wheat germ, brown rice, almonds, cashews, hazelnuts, sunflower seeds, beans, Swiss chard and hard (high mineral) water.
Supplements: Diet usually adequate, but supplementing via multivitamin is OK. Vitamin D and calcium increase absorption.
Too much: UL = 350 mg, supplements only; no upper limit via diet. Too much causes diarrhea, confusion, muscle weakness, nausea, irregular heartbeat and low blood pressure.
Interactions: Some diuretics, antibiotics and cancer medications; high intakes of zinc, fiber and protein.
Phosphorus
Why: Helps calcium make teeth and bones strong; also involved in energy production.
How much: RDA = 700 mg.
Deficiency: Rare; symptoms could include weak bones and muscles, fatigue, loss of appetite, bone pain and increased susceptibility to infection.
Foods: Milk, yogurt, cheese, eggs, whole wheat bread, soft drinks, turkey, salmon, halibut, peanuts, almonds and lentils.
Supplements: Not necessary or recommended.
Too much: UL = 4,000 mg daily before age 70; 3,000 mg daily after age 70. Overdose causes kidney damage.
Interactions: Aluminum-containing antacids, potassium supplements and potassium-sparing diuretics.
Research note: Some animal studies have linked phosphorus intake to weak bones, theoretically from increased calcium losses or decreased calcium absorption.
Sodium
Other names: Sodium chloride (table salt), sodium citrate, monosodium glutamate (MSG), sodium nitrate, sodium bicarbonate (baking soda), sodium phosphate (baking powder) and sodium saccharin.
Why: Regulates body fluids and blood pressure and helps nerve impulse function and muscle contraction.
How much: No RDA; DV is 2,400 mg. (Typical American's intake 4,000 to 6,000 mg daily.)
Deficiency: Less than 500 mg daily leads to headache, nausea, dizziness, fatigue, muscle cramps and fainting.
Foods: Softened drinking water; salt. (75 percent of our salt intake comes from sodium added to seasonings or processed foods.)
Supplements: Not necessary or recommended.
Too much: No UL determined; excess may cause high blood pressure, stomach cancer, kidney stones, cataracts and osteoporosis.
Interactions: Diuretics, NSAIDs, opiates and tricyclic antidepressants. People taking corticosteroids should stay below 3,000 mg daily.
Research note: One study found women who consumed a high-salt diet (9,000 mg daily) lost 33 percent more calcium and 23 percent of a bone protein than those on a low-salt diet (2,000 mg/day).
Chromium
Why: Helps body use insulin, protein, fat and carbohydrates.
How much: AI = 35 mcg for men age 14 to 50; 30 mcg for men over age 50; 25 mcg for women age 14 to 50; 20 mcg for women over age 50.
Deficiency: Impaired glucose utilization.
Foods: Whole grains, wheat germ, brewer's yeast, green beans, prunes, nuts, peanut butter, potatoes, peas, eggs and cheese.
Supplements: Not necessary or recommended.
Too much: No known symptoms.
Interactions: None known.
Research note: Some claim chromium supplements can prevent or treat diabetes, but there is no scientific proof.
Copper
Other names: Cupric oxide, copper gluconate, copper sulfate and copper citrate.
Why: Helps build red blood cells, transport iron and make connective tissue; keeps immune system, nerves and blood vessels healthy; and removes free radicals.
How much: RDA = 900 mcg daily for adults.
Deficiency: Rare; anemia and immune and nervous system disorders.
Foods: Oysters, crab, beef liver, barley, beans, cashews, sunflower seeds, semi-sweet chocolate, peanut butter, lentils and mushrooms.
Supplements: Not necessary or recommended; a multivitamin, which typically provides the RDA, is OK.
Too much: UL = 10,000 mcg: nausea, vomiting, diarrhea, abdominal pain, headache or death.
Interactions: High levels of zinc, iron and possibly vitamin C can block copper absorption.
Research note: Although copper does have anti-inflammatory properties, there currently is no research to support dietary copper or supplementation as a treatment for arthritis.
Fluoride
Why: Necessary for strong bones and teeth (especially tooth enamel).
How much: AI = 4 mg for men; 3 mg for women.
Deficiency: Tooth decay.
Foods: Fluoridated water, tea and canned salmon and sardines (with the bones).
Supplements: By prescription only for infants and children without access to fluoridated water.
Too much: UL = 10 mg daily: mottled and brown teeth.
Interactions: Calcium supplements and calcium- and aluminum-containing antacids.
Research note: Fluoride can help build strong bones and teeth, but it cannot decrease bone loss, so it doesn't prevent osteoporosis. There are safety concerns related to joint pain and stress fractures from taking extremely high doses.
Iron
Other names: Ferrous fumarate, ferrous gluconate and ferrous sulfate.
Why: Necessary for hemoglobin, the protein in red blood cells that carries oxygen to all cells.
How much: RDA = 8 mg daily for men; 18 mg daily for women, until menopause; 8 mg daily for women, after menopause.
Deficiency: The most common form of nutritional deficiency, mostly affecting young children, female teenagers and women of childbearing years. Symptoms of mild deficiency include tiredness, shortness of breath, decreased mental performance, poor appetite, unstable body tem- perature and decreased immunity.
Foods: Heme iron comes from beef, lamb, chicken, turkey, veal liver, ham, bologna or tuna, and is well absorbed by the body. Non-heme iron comes from plant sources and fortified grains like raisins, peas, lentils, figs, oatmeal and grits and is not as well absorbed.
Supplements: Men and postmenopausal women should take multivitamins or other supplements with little or no iron, unless directed by their doctor.
Too much: UL = 45 mg per day: nausea, vomiting, diarrhea or constipation and dark-colored stools. Iron overload comes from hemochromatosis, a genetic disorder that largely goes undiagnosed but is more common than once thought. Iron builds up in body tissues and vital organs, leading to cirrhosis, diabetes, heart disease and arthritis (particularly in the knuckles). High levels also lower zinc absorption.
Interactions: Calcium. Vitamin C-rich foods (orange juice, lemon, tomatoes and peppers), meat, fish, poultry, citric acid and cream of tartar enhance absorption of iron from plant sources. Coffee, tea, wine, tofu, legumes, grains and rice inhibit absorption of iron from plant sources.
Selenium
Other names: Sodium selenite, selenomethionine (organic form found in food) and sodium selenate (inorganic, supplement form).
Why: Works with vitamin E as an antioxidant; essential for proper function of immune system and thyroid gland.
How much: RDA = 55 mcg daily.
Deficiency: Rare; impaired immunity and heart damage.
Foods: Brazil nuts, walnuts, brewer's yeast, wheat germ, shrimp, crab, tuna, turkey and garlic.
Supplements: Not recommended beyond a multivitamin.
Too much: UL = 400 mcg daily. Toxic above 800 mcg a day. Hair and nail loss, nausea, fatigue, nerve damage and muscle problems.
Research note: Supplementation of 200 mcg daily may lower the risk of prostate cancer in men, but further studies must be done before scientists make any recommendations. Although people with RA tend to have low selenium levels, there is no evidence that selenium supplements are beneficial.
Zinc
Other names: Zinc gluconate and zinc acetate.
Why: Involved in wound healing, cell reproduction and tissue growth, sexual maturation, and taste and smell; also associated with more than 100 enzymatic reactions in the body.
How much: RDA = 11 mg daily for men; 8 mg daily for women.
Deficiency: Mild deficiency impairs immunity, leading to poor wound healing and infection.
Foods: Oysters, mussels, lobster, beef, pork, lamb, chicken, turkey, milk, cheese, yogurt, pure maple syrup, peanuts, peanut butter, beans and lentils.
Supplements: Multivitamins with no more than 100% DV recommended.
Too much: UL = 40 mg daily: immune suppression (same as deficiency), diarrhea, abdominal cramps and vomiting and copper deficiency.
Interactions: Antibiotics (particularly tetracyclines), fluoroquinolones and anticonvulsant medications, calcium supplements and fiber.
Research note: Zinc may protect against age-related macular degeneration.
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