Major functions and sources of selected minerals

A mineral is defined as inorganic element containing no carbon that remains as ash when food is burned. Although as many as 40 minerals are in existence, the table below describes the 17 minerals that are essential to human nutrition and lists their functions and sources in food.

Mineral Function Sources
Calcium Strengthens bones and teeth; involved in muscle contraction and relaxation, blood clotting, water balance, nerve function Milk and milk products, green leafy vegetables, legumes, fortified foods, almonds, fish (with bones), tofu
Phosphorus Involved in calcification of teeth and bones, acid-base balance, energy metabolism Meat, poultry, fish, milk, soft drinks, processed foods, whole grains, eggs
Sodium Promotes acid-base balance, water balance, nerve impulse transmission, muscle activity Salt, soy sauce, processed foods: cured, canned, pickled, and many prepackaged foods
Potassium Facilitates many reactions, especially protein synthesis, water balance, nerve transmission, muscle contraction Meats, milk, fruits, vegetables, grains, legumes
Sulfur Component of protein; part of biotin, thiamin, insulin All protein-containing foods
Chloride Part of stomach acid, acid base balance, water balance Table salt, soy sauce; processed foods
Magnesium Involved in protein synthesis, muscle contraction, nerve transmission Whole grains, nuts, legumes, chocolate, meat, dark green leafy vegetables, seafoods, cocoa
Iron Hemoglobin formation, part of myoglobin in muscles; used in energy utilization Red meats, fish, poultry, shellfish, eggs, legumes, dried fruits, fortified cereals and grains
Iodine Part of thyroxine, a thyroid hormone that influences growth and metabolism Iodized salt, seafood, bread
Zinc Part of insulin and enzymes; vitamin A transport; wound healing; fetus and sperm development; immunity; promotes enzyme activity and metabolism Protein-containing foods: red meat, seafood, oysters, clams, poultry, eggs, dairy, grains
Selenium Antioxidant; works with vitamin E; immune system response Seafood, meats, grains
Manganese Essential for normal bone development; activates enzymes Whole grains, legumes, nuts, green leafy vegetables, meat, tea, coffee
Copper Necessary for formation of hemoglobin; part of energy metabolism enzymes Organ meats, shellfish, nuts, seeds, legumes, peanut butter, chocolate
Fluoride Formation of bones and teeth; provides resistance to dental caries Drinking water (naturally occurring or fluoridated), tea, seafood
Chromium Enhances effect of insulin; aids in metabolism of carbohydrates and lipids Mushrooms, dark chocolate, prunes, nuts, asparagus, brewer's yeast, whole grains, vegetable oils
Molybdenum Cobalt Aids in oxidation reactions As part of vitamin B12, aids in nerve function and blood formation Legumes, cereals, grains, organ meats Meats, milk, and milk products