11.7 – A Prelude to Trace Minerals

Learning Objectives

  • Describe the functional role, intake recommendations and sources of  trace minerals

Trace minerals are classified as minerals required in the diet each day in smaller amounts, specifically 100 milligrams or less. These include copper, zinc, selenium, iodine, chromium, fluoride, manganese, molybdenum, and others. Although trace minerals are needed in smaller amounts it is important to remember that a deficiency in a trace mineral can be just as detrimental to your health as a major mineral deficiency.

 

an illustration listing major and trace minerals.
Figure 11.7.1: The Trace Minerals. Image by Allison Calabrese / CC BY 4.0.
Major minerals listed above are: sodium, potassium, chloride, calcium, phosphorus, magnesium, sulfur. Trace minerals listed above are: iron, copper, zinc, selenium, iodine, chromium, fluoride, manganese, and molybdenum.

 

Iodine deficiency is a major concern in countries around the world such as Fiji. In the 1990s, almost 50% of the population had signs of iodine deficiency also known as goiter. To combat this national issue, the government of Fiji banned non-iodized salt and allowed only fortified iodized salt into the country in hopes of increasing the consumption of iodine in people’s diets. With this law, and health promotion efforts encouraging the consumption of seafood, great progress has been made in decreasing the prevalence of iodine deficiency in Fiji.  The US population has had relatively stable levels of iodine since the introduction of iodized salt. However, mild iodine deficiencies have re-emerged during pregnancies in the US. The American Thyroid Association® has recommended that all U.S. women who are planning pregnancy, pregnant, or breastfeeding take a prenatal multivitamin containing 150 μg iodine per day.

 

Table 12.1.1: Summary of Trace Minerals
A table that summarizes several micronutrients
Micronutrient Sources Recommended Intakes for Adults Major Functions Deficiency Diseases and Symptoms Groups at Risk for Deficiency Toxicity U.L.
Iron Red meat, egg yolks, dark leafy vegetables, dried fruit, iron-fortified foods 8-18 mg/day Assists in energy production, DNA synthesis required for red blood cell function Anemia: fatigue, paleness, faster heart rate Infants and preschool children, adolescents, women, pregnant women, athletes, vegetarians Liver damage, increased risk of diabetes and cancer 45 mg/day
Copper Nuts, seeds, whole grains, seafood 900 mcg/day Assists in energy production, iron metabolism Anemia: fatigue, paleness, faster heart rate Those who consume excessive zinc supplements Vomiting, abdominal pain, diarrhea, liver damage 10 mg/day
Zinc oysters, wheat germ, pumpkin seeds, squash, beans, sesame seeds, tahini, beef, lamb 8-11 mg/day Assists in energy production, protein, RNA and DNA synthesis; required for hemoglobin synthesis Growth retardation in children, hair loss, diarrhea, skin sores, loss of appetite, weight loss Vegetarians, older adults Depressed immune function 40 mg/day
Selenium Meat, seafood, eggs, nuts 55 mcg/day Essential for thyroid hormone activity Fatigue, muscle pain, weakness, Keshan disease Populations where the soil is low in selenium Nausea, diarrhea, vomiting, fatigue 400 mcg/day
Iodine Iodized salt, seaweed, dairy products 150 mcg/day Making thyroid hormone, metabolism, growth and development Goiter, cretinism, other signs and symptoms include fatigue, depression, weight gain, itchy skin, low heart-rate Populations where the soil is low in iodine, and iodized salt is not used Enlarged thyroid 1110 mcg/day
Chromium Not Determined 25-35 mcg/day Assists insulin in carbohydrate, lipid and protein metabolism abnormal glucose metabolism Malnourished children None Not Determined
Fluoride Fluoridated water, foods prepared in fluoridated water, seafood 3-4 mg/day Component of mineralized bone, provides structure and microarchitecture, stimulates new bone growth Increased risk of dental caries Populations with non fluoridated water Fluorosismottled teeth, kidney damage 10 mg/day
Manganese Legumes, nuts, leafy green vegetables 1.8-2.3 mg/day Glucose synthesis, amino-acid catabolism Impaired growth, skeletal abnormalities, abnormal glucose metabolism None Nerve damage 11 mg/day
Molybdenum Milk, grains, legumes 45 mcg/day Cofactor for a number of enzymes Unknown None Arthritis, joint inflammation 2 mg/day

 

Key Takeaways

Refer to the table above for a summary of the Trace minerals

 

Contributors


University of Hawai’i at Mānoa Food Science and Human Nutrition Program: Allison Calabrese, Cheryl Gibby, Billy Meinke, Marie Kainoa Fialkowski Revilla, and Alan Titchenal