Our bodies need an assortment of minerals to support essential daily functions and processes. A century ago, we relied on a varied diet packed with vitamins, minerals, and nutrients to meet those needs. The soil in which fruits and vegetables grew contained important minerals. But today, “the agricultural soil is depleted of most minerals,” says Carolyn Dean, medical doctor, naturopath, and medical advisory board member for the Nutritional Magnesium Association. “For example, 100 years ago, we could get 500 milligrams of magnesium in our diet. Now, we’re lucky if we get 200 milligrams.”
Fortunately, multivitamins and supplements can make up for the lack of minerals in our diets. We require macrominerals—calcium, sodium, and potassium, to name a few—in relatively large amounts. But a second category of minerals, trace minerals, is often overlooked.
What Are Trace Minerals?
“Trace minerals are minerals that we need in smaller amounts than macrominerals,” explains Ysabel Montemayor, a registered dietitian at Fresh n’ Lean meal delivery service.
Defined by the small amounts required by the body, trace minerals—at times occurring in the body as micrograms (µg)—go a long way in terms of keeping your heart, hormones, and bones healthy.
Of the 103 known mineral varieties, at least 18 of them are considered trace minerals, including iron, zinc, magnesium, manganese, copper, and phosphorous.
Function of Trace Minerals
Trace minerals have varying functions related to health, including energy production, cardiovascular function, immune defense, hormone regulation, and bone metabolism, among others. “Rather than acting as the main player in these processes, they’re usually facilitators—charge conductors or shapeshifters that are critical to healthy function,” explains Melissa A. Murphy, assistant professor of nutrition and basic sciences at Bastyr University in San Diego.
Dr. Dean adds that they “act as the building blocks for hundreds of enzymes and manage numerous bio-chemical reactions.” But most trace minerals, she says, “haven’t been defined as to their function.” Take magnesium, necessary for as many as 700 to 800 enzymatic reactions in the body. A study shows magnesium deficiencies, which increase the risk of cardiovascular disease, often go undiagnosed to the point of being a modern health crisis (1). Overall mineral deficiencies, Dr. Dean says, can result in a variety of issues, such as weak bones, fatigue, or decreased immune-system function.
6 Key Trace Minerals and How to Get Them
Let’s take a closer look at a few key trace minerals and how you can increase your intake.
Concentrated in the bones, thyroid, and spleen, boron improves calcium absorption and interacts with magnesium and vitamin D to maintain bone density. It directs calcium into bone and cartilage, where it belongs, and also helps increase muscle mass and strength while decreasing body fat, Dr. Dean says.
“When boron is deficient, (it) can cause skin rashes, increased allergy symptoms, and more frequent infections,” adds Dr. Dean. It’s currently being looked at as a treatment for high cholesterol, poor memory, and some tout it for anti-arthritis powers. Find it in nuts and fruits: raisins, almonds, hazelnuts, and dried apricots.
A latecomer to the nutrient scene, chromium was recognized as an essential element in 1959. Chromium affects carbohydrate metabolism, is involved in the metabolism of amino acids, fats, and nucleic acids (the building blocks of RNA and DNA), and helps balance blood sugar, making it especially important for diabetics, Dr. Dean says. It also assists in lowering cholesterol and elevating sperm counts.
Our bodies contain about 2 to 6 milligrams of chromium. Food sources include brewer’s yeast, meat, liver, and whole wheat—but remember, these foods “are high in chromium only if the soil in which (they were) grown or where animals grazed contains chromium” says Dr. Dean.
Only about 5 percent of your copper intake is absorbed through the intestines, where adults store about 80 to 100 milligrams. “The mineral is used in iron metabolism, cellular signaling, neurotransmitter production, and as an antioxidant,” Murphy says. “A deficiency may cause brittle hair, bone spurs, fatigue, and impaired memory formation.”
Good sources of copper include meat and shellfish, nuts, seeds, legumes, and dried fruit, but check with a doctor before supplementing. While necessary for good health, copper is a mineral that must be taken in proportion with zinc. Too much copper, which acts as a brain stimulant, and not enough zinc may cause issues such as ADHD, paranoia, and psychosis, Dr. Dean says. Other minerals may also affect copper absorption, so work with your health care provider to schedule your supplements correctly.
Iodine is essential to the structural formula for T3 and T4 thyroid hormones in your thyroid gland, what some consider the most important gland in the body. It’s involved in most—if not every—bodily process. “Of the 10 to 30 milligrams of iodine in your body, it is mostly in your thyroid,” Dr. Dean says. A deficiency may cause goiter (an enlargement of the thyroid), diminished concentration, and reduced body temperature.
Some of the most common sources of iodine are sea salt, iodized table salt, shellfish, and ocean fish. The recommended dietary allowance (RDA) for iodine is just 150 micrograms, but Dr. Dean has found that most people she’s worked with are deficient; certain chemicals, such as bromine and chlorine, in our diet and environment can block iodine absorption. Work with a health care provider to find out your iodine level and, if necessary, how to supplement correctly.
Selenium is a super antioxidant. This trace mineral is part of the structure of glutathione, a potent antioxidant found in most cells in the body that has 1,000 times the power of vitamin E. Because of these qualities, selenium has been touted as a treatment and preventive measure for several forms of cancer—skin, liver, lung, breast, and intestine. A 2011 review of 55 related studies found limited evidence suggesting that individuals with higher selenium levels have a lower incidence of cancer (2). However, it is not possible to conclude from these studies that selenium was the reason for the lower cancer risk, because a high selenium level might be associated with other factors that reduce cancer risk, such as a healthier diet or lifestyle.
According to Murphy, selenium is also an important part of the immune system and thyroid hormone synthesis, converting T4 to the more active T3.
Our bodies contain about 10 to 30 milligrams of selenium, and the RDA for an adult is 50 micrograms. When there is a deficiency, it presents as hypothyroidism, impaired immune function, and blood sugar imbalance and weight gain, says Dr. Dean. The best source of selenium is sardines, where the mineral is found in the skin, but other sources include raw dairy products, garlic, blue corn, brewer’s yeast, and almonds.
We have about 3 grams of zinc in our bodies, 90 percent of which is found in red and white blood cells. The mineral helps regulate brain neurotransmitters and sex hormones, create DNA and RNA, and promote wound healing, plus zinc-containing enzymes are involved in many aspects of metabolism. A deficiency can result in hypothyroidism, impaired growth or healing, and a loss of appetite, Murphy says, but zinc is available in red meats, seafood, poultry, pork, dairy products, whole grains, legumes, and fortified cereals.
Supplementing with zinc may block the absorption of other minerals such as copper and manganese, Dr. Dean says. Speak with a doctor to determine how much to take and at what time in relation to other supplements.
Do I Need a Mineral Supplement?
It’s still best to get trace minerals from food sources. “Eating a variety of foods (may) eliminate the need for supplementation,” says Montemayor.
Certain types of salt are also great sources of trace minerals. “There are upward of 84 trace minerals in Himalayan salt and 72 in sea salt—these are the ultimate sources for trace minerals,” Dr. Dean says. But supplementation is also an option and today, supplements come in pill form as well as powder (which can be mixed with hot or cold liquids) and trace mineral drops.
When choosing a supplement, Murphy suggests making sure that the product has been tested by an external source verifying the contents. To avoid any potential toxicity—which may occur when taking too much of any mineral—consider the Dietary Reference Intakes (DRI) issued by the Food and Nutrition Board of the Institute of Medicine (3). It bears repeating that, since many minerals compete with each other for absorption, it’s important to time the use of supplements well to get the most out of them and be sure they don’t in
terfere with other nutrients. Ideally, speak with a doctor or nutritionist to find the right supplement dosage and timing.