Types of Trace Minerals

Dietary minerals are essential to life. They form two categories, macrominerals and trace minerals or micronutrients. Intake of less than 100 milligrams per day is needed for trace minerals and over 100 milligrams per day is needed for macrominerals. Excess consumption of a mineral can lead to toxicity. Macrominerals are calcium, phosphorus, magnesium, sodium, and potassium. Trace minerals are iron, zinc, iodine, selenium, chromium, copper, fluorine, manganese and molybdenum. Some other micronutrients are needed in very small amounts: boron, cobalt, germanium, silicon, and vanadium.

Iron

• LIver is an important source of dietary iron.

  Iron is the center of the hemoglobin molecule which transports oxygen. The minimum dose is 18 mg per day and the maximum is 45 mg. Lack leads to iron-deficiency anemia; too much leads to damaged body tissues. Sources are red meats, shellfish, liver, egg yolk, beans and nuts.

Zinc

• Peanuts contain the trace element zinc.

  The body's immune system and senses of taste and smell need zinc to work properly. Zinc is important in wound healing, cell growth and carbohydrate breakdown. Minimum dose is 11 mg and maximum dose is 40 mg. Lack causes slow healing and growth, problems with taste and smell, hair loss, decreased appetite and poor night vision. Sources are beef, pork, lamb, dark chicken meat, peanuts and legumes.

Iodine

• Table salt is iodized in the United States to prevent serious illness.

  Iodine is essential to thyroid function. Lack causes goiter and, in infancy and childhood, mental retardation. Minimum dose is 150 micrograms and maximum dose is 1.1 mg. Iodine is added to salt in the United States, and is also present in seafood, ocean fish, seaweed, dairy products, and plants grown in iodine-rich soils.

Selenium

• Turkey meat is a source of selenium, important in immune system function.

  This mineral is incorporated into proteins to make selenoproteins. They function as antioxidants and help regulate thyroid function and the immune system. Daily minimum dose is 55 micrograms; maximum dose is 400 micrograms. Sources are nuts, tuna, beef, cod, turkey, eggs, and oatmeal, but only if they have been raised where selenium is plentiful.

Copper

• The trace mineral copper is present in chocolate.

  Copper helps provide energy, transforms melanin into skin pigments, and helps with connective tissue strength. Minimum dose is 900 micrograms; maximum is 10 mg. Lack causes heart and circulatory problems, bone and immune system complications. Sources are seafood, nuts, wheat bran, organ meats, raisins and chocolate.

Fluorine

• Toothpastes and drinking water contain the trace mineral fluorine as fluoride.

  Fluorine as fluoride is added to drinking water and toothpaste in the United States. It is necessary for strengthening bones and teeth. Minimum dose is 3 micrograms, maximum is 10 mg. Other sources are seafood and tea.

Manganese

• Manganese can be found in avocados.

  Manganese is important in food digestion, immune system, cell reproduction, blood sugar levels, energy production, and bone growth. Minimum dose is 1.8 mg and maximum dose is 11 mg. Sources are avocados, berries, nuts, egg yolks, whole grains, legumes, and green leafy vegetables.

Molybdenum

• Beans contain molybdenum if they are grown on molybdenum rich soils.

  Molybdenum is present in all body tissues. It is needed for cell growth and healthy bones, and helps to process iron and nitrogen. Minimum dose is 45 micrograms and maximum is 2 mg. Molybdenum deficiency causes mouth and gum disorders and susceptibility to cancer. Sources are beans, legumes, green leafy vegetables, and grains if molybdenum is present where they grow.

Micronutrients Needed in Very Small Amounts

• Boron, silicon, and vanadium are needed for bone health.

  Boron is essential for bone and brain health. Cobalt is needed in Vitamin B-12. Germanium helps with oxygen availability and stimulates the immune system. Silicon is needed for health of skin, bones and connective tissue. Vanadium is thought to have a role in energy conversion, blood sugar levels and bone formation.