Trace minerals are a subset of micronutrients and essential minerals. They include:
- Fluoride (usually included but rarely tested)
Trace mineral deficiencies can occur worldwide when there is insufficient food, insufficient variety of food, and/or mineral deficiencies in the soil that food is grown in. The World Health Organization lists iodine, iron (and Vitamin A) as the most important micronutrients in terms of global public health. In the United States, both deficiencies and excesses of trace minerals are rare. Deficiencies are sometimes seen with malnutrition and with conditions such as celiac disease that are associated with decreased ability to absorb minerals. Deficiencies may occur with:
- Insufficient intake – such as from a restricted diet. Sometimes seen when someone receives only intravenous nutrition.
- Insufficient absorption – may be seen with a variety of chronic conditions associated with malabsorption and seen with surgeries that remove part of the stomach or intestines.
- Inability to use – some people may not be able to properly utilize one or more trace minerals.
- Increased use/need – pregnant women, children, and those that are recovering from an illness or injury may require increased nutritional support.
- Increased loss – an example of this is the loss of iron that occurs when red blood cells are lost due to acute or chronic bleeding.
- Interference – an example of this is the decrease in copper that is associated with an excess of zinc.
Trace mineral excesses may be seen with:
- Too much intake – this may be chronic or acute, due to taking supplements or to accidental or occupational exposure.
- Decreased loss – with conditions such as kidney and liver disease, the body may not be able to remove trace minerals from the body at a normal rate. With some inherited conditions, the body may store minerals in tissues and organs, resulting in damage to them. An example of this is the storage of copper with Wilson’s disease.
How is the sample collected for testing?Trace mineral testing is usually performed on a blood sample obtained by inserting a needle into a vein in the arm. Sometimes a 24-hour urine collection is obtained. Special metal-free blood or acid-washed urine containers are used to minimize the potential for sample contamination by any outside sources of minerals.
Blood and urine reflect recent mineral intake. Rarely, hair may be collected or a biopsy may be performed to obtain a tissue sample to evaluate mineral deficiencies, excesses, and storage that have occurred over time.
Is any test preparation needed to ensure the quality of the sample?Talk to your doctor; fasting is preferred for some tests.
How is it used?Trace mineral tests are typically ordered individually to detect, evaluate, and monitor mineral deficiencies or excesses. A doctor may select one or more tests based upon what symptoms or underlying conditions a person has. Sometimes more than one test is ordered to detect a single deficiency or toxicity, such as ordering copper and ceruloplasmin together to evaluate the amount of copper in the body, or ordering a group of iron tests (iron, total iron binding capacity, and ferritin) and a CBC (Complete Blood Count) to evaluate iron deficiency as a potential cause of anemia.
If a person has general malnutrition or a condition associated with malabsorption, then a doctor may order several trace mineral tests together for an initial evaluation and then order one or more tests periodically to monitor the person’s nutritional status and/or the effectiveness of treatment.
If someone has an inherited condition that leads to excess concentrations of a mineral or has been exposed to toxic concentrations, then a test for that mineral may be ordered to help detect and diagnose the condition and then ordered at intervals to monitor the person’s condition.
Blood tests are used in most cases to evaluate trace minerals, but some tests may be ordered on a 24-hour urine sample. In cases where minerals are being stored in tissues or organs, a test may be ordered on a biopsy sample to help diagnose and evaluate the severity of the condition.
When is it ordered?With the possible exception of an iron test, trace mineral tests are not routinely ordered on the general population.
Trace mineral tests are ordered whenever a mineral deficiency or excess is suspected due to medical history or signs and symptoms that may be present. Deficiencies in trace minerals can cause a range of symptoms, depending on the mineral(s) that are lacking. Symptoms may include:
In children, deficiencies can cause congenital abnormalities, delay growth, and affect mental development and sexual maturation.
- Skin rash
- Nausea, vomiting and/or diarrhea
- Peripheral neuropathy
- In severe cases, it may result in kidney and liver failure, shock, coma, and an increased risk of lung cancer.
One or more may be ordered periodically to monitor the status of a person with an underlying condition that can cause malabsorption or cause the buildup of an excess trace mineral.
What does the test result mean?In general, low concentrations of a mineral indicate a deficiency and high concentrations indicate an excess. When a person is being treated for a deficiency, then increasing levels and a decrease in symptoms indicate a response to treatment. When a person is being treated for mineral toxicity, then decreasing levels and a decrease in symptoms indicate a response to treatment.
Trace mineral results must, however, be interpreted with some degree of caution. Some treatments for excess mineral can actually increase blood and urine concentrations temporarily and some minerals, such as copper and zinc, may be temporarily increased by infection, inflammation, pregnancy, and a variety of diseases. Many of the symptoms associated with trace mineral deficiencies and excesses may also be seen with a variety of other conditions. The doctor will interpret findings in conjunction with the person’s symptoms and clinical history.
Is there anything else I should know?Trace minerals are found in varying concentrations in a wide variety of foods. Some forms of the mineral are more “bioavailable” from an animal than a plant source, such as heme-iron versus non-heme iron. Some minerals have been added to foods to make them more readily available, such as “fortified” grains and cereals, fluoridated water, and iodized salt.
Should everyone be tested for trace minerals?It is not generally necessary. Most people in the United States who eat a variety of foods will get a sufficient amount of trace minerals in their diet.
How long will it take to get the results of my test?
Should I take mineral supplements?Talk to your doctor about taking supplements. If you are deficient, they may be of benefit to you, but taking large doses of most trace elements over time can increase your risk of toxicity. Those who take excess zinc can inhibit their use of copper. People who store excess iron or copper in their bodies must restrict and monitor their intake of these minerals as the buildup can damage tissues and organs.
What other minerals are required by the body?Macrominerals are minerals that are required in greater amounts by the body than trace minerals. They include sodium, potassium, calcium, magnesium, chloride, and phosphorus. Some also include sulfur in this category.
What other micronutrients are required by the body?Micronutrients include trace minerals, the fat-soluble vitamins A, D, E, and K, and the water-soluble vitamins C and B complex (biotin, folate, niacin, pantothenic acid, riboflavin, thiamin, B6 and B12).