MINERALS IN THE DIET
Leader's Guide
This is a comprehensive guide to accompany several publications, including HE3-230, Trace Minerals in
Your Diet; HE3-516, Calcium; HE3-517, Copper; HE3-519. Iron; HE3-520, Magnesium; HE3-521,
Potassium; HE3-522, Zinc; and CFS-643 (NCR-540), Vitamins & Minerals in the Food Guide Pyramid;
and the factsheet, A Condensed Summary of Minerals. You may want to handout the CFS-643 publication
and Summary factsheet and use the appropriate publications as guides for your leaders.
More than one-third of the dietary nutrients needed for a healthy body are minerals. Seventeen
minerals are among the nearly 45 dietary nutrients known to be necessary for life and account for four
percent of body weight. The mineral composition of the human body is seen in the following figure. The
"other " category includes potassium, sodium, sulfur, chlorine, iron, zinc, magnesium, iodine and other
trace minerals.
Although minerals represent only a very
small fraction of human body weight, they play
important roles in all areas of the body. They
help form bones and teeth, aid in normal
muscle and nerve activity, act as catalysts in
many enzyme systems, help control water
levels in the body and are components of such
compounds in the body as hemoglobin and the
hormone thyroxine. Evidence is mounting that
certain minerals like calcium and selenium may
help prevent cancer. And that deficiencies of
zinc may decrease the ability of the immune system to function. A condensed summary of minerals is
attached.
Minerals that are essential to the body fall under one of two categories, major and minor.
1. Major minerals are needed in amounts greater than 100 mg/day and include calcium, phosphorus,
magnesium, sodium, chloride, potassium, and sulfur. Sodium, chloride and potassium are also known
as body electrolytes. Sulfur is a part of the essential amino acid, methionine so is easily obtained by
eating protein rich foods.
2. Minor minerals are trace elements needed in amounts of less than a few mg/day and include iron, zinc,
iodine, fluoride, copper, selenium, chromium, cobalt, manganese and molybdenum. Iron, zinc,
selenium and iodine are the only minor minerals that have been studied sufficiently to establish required
dietary amounts (RDA). For the remainder with the exception of cobalt, safe and adequate daily
ranges have been estimated by the Food and Nutrition Board of the National Academy of Sciences.
There are several minerals that may be essential for humans, but research has not established their
importance, including tin, nickel, silicon and vanadium. There are also other minerals found in the body
that are regarded as contaminants including lead, mercury, arsenic, aluminum, silver, cadmium, barium,
strontium and others.
