Trace Elements—Deficiency and Toxicity

People are constantly exposed to a variety of elements, whether from consumption of food or water or occupationally. Many of these elements are necessary for health, but some have no biologic function. Of the mineral elements discussed here, those that have nutritional significance are chromium, cobalt, copper, iodine, iron, manganese, nickel, selenium, and zinc. Those that are not essential to humans are antimony, aluminum, bismuth, beryllium, cadmium, lead, mercury, and thallium. Both essential and nonessential elements can be toxic when levels exceed a certain threshold. Signs and symptoms of toxicity correlate with route of exposure, specific element forms, and type of exposure, whether acute or chronic. Deficiencies of essential minerals may exist in patients with chronic illness, patients having had bariatric surgery, and preterm infants.

Laboratory tests are important in the diagnosis of metal toxicity, but they are only a part of the diagnosis; to confirm a diagnosis of exposure, a patient must have signs or symptoms consistent with the exposure, a source of exposure, and atypical concentrations of the element.  ARUP Laboratories offers element exposure testing for a variety of specimen types, as well as panel testing for common heavy metals. See Emergency Toxicology as an additional resource for testing information.

Quick Answers for Clinicians

How should results be interpreted with respect to provided reference intervals?

An ARUP Laboratories test result designated with a less than sign (<) means that the result is below the limit of quantification of the assay. Interpretive comments are provided to assist with the interpretation of the result and may provide element-specific toxic range and reference range information.

What are the methodologies used for detecting trace and toxic elements?

The majority of element toxicity and deficiency testing is performed by quantitative inductively coupled plasma-mass spectrometry (ICP-MS). Zinc protoporphyrin testing, however, is performed by quantitative hematofluorometry.

Which specimen types are preferred for detecting exposure?

In an emergency toxicology situation, blood or serum can be used to assess recent or acute exposure. Recommended specimen types for detecting deficiency or overload depend on the element. Specific recommendations for each element are provided below.

What is important to know about specimen collection to avoid contamination?

To avoid contamination that can cause false-positive results, preanalytic variables should be controlled by using proper collection techniques and trace-free collection tubes. ARUP Laboratories requires certified metals-free transport tubes, which are available for ordering. Refer to the Trace Elements Specimen Collection Guide for more details about metals-free collection.

Aluminum

Aluminum is the most abundant metal in the Earth’s crust and is found throughout the environment, but exposure from food, water, and dermal contact (eg, antiperspirants and sunscreen lotion) is low. Intake of aluminum is greatest from aluminum-containing remedies, including antacids and antidiarrheal and antiulcerative medications. Aluminum is also used in beverage cans, pots and pans, and foil. It accumulates in the skeleton and lungs, but the brain and nervous system are most affected by excess aluminum. A typical dietary intake of aluminum is normally completely eliminated from the blood by the kidneys, but patients with renal failure are at particular risk for aluminum toxicity due to a reduced ability to filter aluminum from the blood.

Biologic function

None

Sources

Antacids, cookware, food packaging, baking powder, antiperspirants

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Osteomalacia, bone fractures, bone deformities, muscle weakness, seizures, encephalopathy, dementia, slow growth in children

Recommended daily adult intake

Not applicable

Indications for Testing

Patients with a known or suspected source of exposure and corresponding symptoms should be tested for aluminum exposure. Patients undergoing dialysis are at increased risk for aluminum exposure from contaminated dialysate water or aluminum-containing phosphate binders; however, the Kidney Disease: Improving Global Outcomes (KDIGO) organization recommends precautions to avoid aluminum intoxication. Nonaluminum-containing treatments and procedures are available.

Laboratory Testing

Diagnosis

Serum

Serum aluminum levels best reflect recent exposure. Serum is the preferred specimen type for routine screening and for the assessment of toxicity due to dialysis. Serum levels in healthy individuals range from 1-3 µg/L.  A serum aluminum level >50.0 µg/L is consistent with overload and may correlate with toxicity.

Urine

Urine aluminum levels are more appropriate for determining chronic exposure.

Monitoring

KDIGO no longer recommends regular monitoring of serum or plasma aluminum levels. However, KDIGO does recommend avoiding long-term use of aluminum-containing phosphate binders in patients with chronic kidney disease, stages 3-5D, and use of aluminum-contaminated dialysate in patients with chronic kidney disease, stage 5D. 

Antimony

Antimony is a metalloid that is naturally found in soil but is not an essential nutrient for human function. The general population can be exposed to low levels in air, water, or food, or from polyethylene terephthalate water bottles and fire retardants.  Workers in the antimony industry (production of fire retardants, glass, hard alloys, etc.) are at risk for higher, toxic levels of exposure. Exposure can cause delayed growth in children, dermatitis and inflammatory lesions, pulmonary damage, myocardial damage, and gastrointestinal irritation.

The form of antimony greatly influences distribution and elimination. Trivalent antimony readily enters red blood cells, has a half-life of weeks to months, and is eliminated predominantly through the bile. Pentavalent antimony resides in the plasma, has a relatively short half-life of hours to days, and is eliminated predominantly through the kidneys.

Biologic function

None

Sources

Soil, drinking water, air, polyethylene terephthalate water bottles

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Acute exposure: headache, nausea, dizziness, metallic taste, followed by vomiting, diarrhea, intestinal spasms

Chronic exposure: arrhythmia, respiratory irritation, eye irritation, spontaneous abortion (miscarriage) or premature birth, dermatitis, damage to liver and spleen

Recommended daily adult intake

Not applicable

Indications for Testing

Individuals with a known or suspected source of exposure and corresponding symptoms should be tested for antimony exposure.

Laboratory Testing

Diagnosis

Blood

Blood antimony levels predominantly reflect recent exposure and are most useful in the diagnosis of acute poisoning. Blood concentrations in unexposed individuals rarely exceed 3 µg/L.

Urine

Although most people in the United States have a small amount of antimony in their urine, high levels in blood or urine indicate recent exposure to an amount greater than normal. 

Hair

Antimony levels in hair are not a reliable indicator of exposure. 

Arsenic

Arsenic is found naturally in the Earth’s crust and exists in toxic and nontoxic forms. Nontoxic arsenic, or organic arsenic, is found in seawater and in several foods, notably shellfish and dark-meat fish. Inorganic arsenic is highly toxic; it is most readily found in pesticides but is also used in glass and ceramic production and in some pharmaceuticals. Children are more susceptible to toxins due to a higher metabolic rate, a developing nervous system, and increased hand-to-mouth behavior; they are also less able to methylate arsenic. Additionally, arsenic is known to cross the placenta and accumulate in the fetus. Syndromes of arsenic toxicity can present as acute, chronic, or latent. Appropriate specimen choice and testing are important to a successful diagnosis.

Biologic function

Not applicable

Sources

Contaminated water and food, smoking tobacco, industrial processes

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Acute: abdominal pain, vomiting, diarrhea, muscle cramps, high blood pressure, rapid heart rate

Chronic: hyperpigmentation of skin, muscle weakness, anemia, leukopenia, skin lesions, skin cancer, sensory-predominant peripheral neuropathy

Recommended daily adult intake

Not applicable

Indications for Testing

Acute arsenic exposure is characterized by vomiting, diarrhea, abdominal pain, and, in extreme cases, numbness, tingling, muscle cramps, and death. Chronic exposure (≥5 years of exposure) causes changes in skin pigmentation, skin lesions, and hard patches on hands and bottoms of feet. Individuals with known or suspected exposure and associated symptoms should be tested.

Criteria for Diagnosis

A person is diagnosed with arsenic exposure when urinary arsenic levels are >50 µg/L for a random urine collection or >50 µg total for 24-hour urine collection.  In cases of urine arsenic level elevation, testing must differentiate the amounts of organic and inorganic arsenic.  The American Conference of Governmental Industrial Hygienists (ACGIH) Biological Exposure Index (BEI)  for arsenic in urine is 35 µg/L; the BEI for arsenic is based on the sum of inorganic and methylated arsenic species.

Laboratory Testing

Diagnosis

Urine

Urine is a sensitive marker for low-level arsenic exposure. It is the preferred specimen for detection of acute exposure due to the short half-life of arsenic in the blood.  Concentrations of methylated arsenic species in urine peak 40-60 hours after ingestion and return to baseline after 6-20 days. A 24-hour urine arsenic level is useful for the detection of chronic exposure. Elevated results should be fractionated to differentiate between toxic, inorganic forms and relatively nontoxic, organic forms.

Blood

Blood arsenic testing is used for the detection of recent exposure (<24 hours since exposure) and large-dose poisoning only. In blood, the half-life of inorganic arsenic species is 4-6 hours, and the half-life of methylated arsenic species is 20-30 hours. Arsenic binds to hemoglobin, and, as a result, there is three times more arsenic in hemoglobin than in plasma.

Other

Hair or nail testing can detect chronic or past exposures of >3 weeks and is most useful in determining time of exposure. Hair is a poor specimen type for assessing arsenic exposure at low or moderate levels and can become contaminated by arsenic-containing water.

Beryllium

Beryllium is a poisonous earth metal not necessary for human health. It inhibits the alkaline phosphatase, acid phosphatase, phosphoglycerate mutase, hexokinase, and lactate dehydrogenase enzyme systems in the body. Exposure through food and water is not clinically significant, owing to the low level of exposure and the limited absorption of beryllium by the stomach and intestines.  However, chronic industrial exposure, which occurs from inhaling insoluble beryllium compounds through the respiratory tract, can cause chronic beryllium disease (CBD), or berylliosis. CBD is a potentially fatal respiratory condition that is diagnosed with a beryllium lymphocyte proliferation test (BeLPT) and biopsy.   Acute exposure is rare but can happen from an industrial explosion. Beryllium is used in nuclear weapons, spacecrafts, circuit boards, dental bridges, and sports equipment, among other applications. Beryllium chloride (soluble compound) has a pulmonary half-life of 20 days, and beryllium oxide (insoluble compound) has a pulmonary half-life of about one year. Beryllium compounds are classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC). 

Biologic function

None

Sources

Air in and around beryllium mines and processing plants

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Weakness, fatigue, difficulty breathing, rash or ulcers on open skin, anorexia, weight loss

Recommended daily intake

Not applicable

Indications for Testing

Patients with a known or suspected source of exposure and corresponding symptoms should be tested for beryllium exposure. Common symptoms include shortness of breath, dry cough, chest pain, and fatigue.

Laboratory Testing

Diagnosis

While a serum beryllium test can confirm an exposure, a diagnosis of CBD requires 

  • Appropriate history of exposure,
  • A positive blood or bronchoalveolar lavage (BAL) BeLPT, and
  • Granulomatous inflammation on lung biopsy.
Beryllium Lymphocyte Proliferation

The BeLPT identifies beryllium sensitization; it can help predict CBD but alone does not diagnose CBD. The test can be performed with either blood or fluid from BAL. Testing can be used in asymptomatic individuals with chronic exposure to beryllium or in symptomatic individuals with a history of beryllium exposure. Patients with an elevated number of cells are sensitized to beryllium and are at greater risk for developing CBD.

Serum

Serum beryllium testing measures the amount of beryllium in serum and can confirm an exposure to beryllium; however, it does not indicate the extent of exposure or how recently the patient was exposed.

Monitoring

Patients who are diagnosed with CBD require lifelong follow up with serial arterial blood gases, chest x-ray, and pulmonary function tests; those with beryllium sensitization in the absence of CBD should undergo periodic evaluation but do not need treatment. 

Bismuth

Bismuth is a metal that is often formulated into a salt used in medications to treat vomiting, diarrhea, and ulcers. It is also used in ceramic and glass manufacturing and in the production of alloys and castings. Toxicity resulting from ingestion, although rare, mostly affects the kidneys, liver, and bladder.

Biologic function

Not applicable

Sources

Pharmaceuticals for treatment of nausea, vomiting, diarrhea

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Acute: foul breath, oral mucosal lesions, renal toxicity

Chronic: discoloration of skin, encephalopathy manifesting as memory loss, delirium, psychosis, insomnia, seizures

Recommended daily adult intake

Not applicable

Therapeutic range: <0.1 µg/L

Indications for Testing

Individuals with a known or suspected source of exposure and corresponding symptoms should be tested for bismuth exposure.

Laboratory Testing

Diagnosis

Blood

Bismuth exposure can be evaluated by blood or urine testing, but whole blood is a better indicator of bismuth exposure because bismuth is normally rapidly excreted in urine.  A blood bismuth concentration <5 µg/dL is a normal level and is rarely associated with symptoms. 

Cadmium

Cadmium is a heavy metal that has not been shown to have any human physiologic function but is present in all soil. Industrially, it is used in the production of batteries, plastics, metal plating, and as pigments. Most cadmium exposure is occupational, but outbreaks can occur as an effect of mining pollution. Cadmium not only is toxic in moderate amounts but also counteracts several necessary minerals.  Cadmium damages the kidneys, lungs, and bones, and increases the risk of developing lung cancer. 

Biologic function

None

Sources

Shellfish, liver and kidney meats, tobacco products and tobacco smoke, contaminated water

Signs and symptoms of deficiency

Not reported in humans

Signs and symptoms of excess

Acute: abdominal pain, vomiting, diarrhea

Chronic: kidney disease leading to glucosuria and proteinuria, lung damage, bone weakness

Recommended daily adult intake

Not applicable

Indications for Testing

Individuals with a known or suspected source of exposure and corresponding symptoms should be tested for cadmium exposure.

Laboratory Testing

Diagnosis

The Occupational Safety and Health Administration (OSHA) recommends a panel that includes both blood and urine cadmium testing as well as a test for beta-2-microglobulin in urine.  Because many collection materials (rubber catheters and colored plastic containers) contain cadmium, it is important to use trace-free collection equipment. See Trace Elements Specimen Collection Guide for ARUP Laboratories’ metals-free collection requirements.

Urine

Urinary cadmium concentrations have been shown to accurately reflect the amount of cadmium stored in the body and can indicate both recent and past exposure.   Urine specimens are recommended for the assessment of chronic exposure.

Blood

The amount of cadmium in blood can be used to determine acute toxicity or recent exposure.  

Chromium

Chromium exists in many forms; the most common are chromium (0), chromium (III), and chromium (VI). Chromium (III) is considered an essential nutrient with low toxicity, but its necessity is unproven.   It is believed to help in the metabolism of sugar, protein, and fat. However, chromium (VI), a known carcinogen, is toxic and can cause ulcers, anemia, and lung cancer. In industrial settings, chromium is used in the manufacturing of steel, in dyes, and for chrome plating, leather tanning, and wood preserving.

Biologic function

Helps in sugar, protein, and fat metabolism

Potentiates the action of insulin in patients with impaired glucose tolerance 

May also improve lipid profiles (proven in animal studies but not in humans)

Sources

Egg yolks, brewer’s yeast, whole-grain products, broccoli, green beans, coffee, nuts, liver, meats, metal-on-metal prosthetic implants

Signs and symptoms of deficiency

Associated with impaired glucose tolerance and diabetes mellitus (DM), weight loss, neuropathy

Signs and symptoms of excess

Kidney failure, anemia, bleeding, liver dysfunction, dermatitis, impaired pulmonary function, gastroenteritis

Recommended adequate intake

20-35 μg/day for adults (age and sex dependent) 

11-35 μg/day for children (age and sex dependent) 

Indications for Testing

Deficiency

Although a state of deficiency has not been clinically defined  and explicit symptoms are limited, individuals at increased risk for chromium deficiency are the elderly, pregnant women, and those with DM. Patients with DM have reduced tissue levels and may have altered chromium metabolism. Studies have shown that chromium supplements can improve glucose and insulin metabolism in those with DM but that the effect of supplementation is limited in those without DM.  Additionally, strenuous exercise, infection, and physical trauma can increase chromium losses.

Toxicity

Symptomatic patients with a known or suspected source of exposure should be tested. Patients with metal-on-metal joint replacements, in particular, are at risk for release of metal debris, which can cause periprosthetic soft tissue reactions and chromium and cobalt toxicity, and can result in neurologic impairment, cardiomyopathy, and hypothyroidism. See Monitoring.

Laboratory Testing

Diagnosis

Chromium can be tested in blood, urine, and hair, but testing does not predict health outcomes, as dietary chromium biomarkers are inconclusive.  A chromium concentration greater than normal levels indicates recent excessive exposure or dietary intake but not body burden.  

Blood

Whole blood is useful for assessing chromium deficiency or overload and is the preferred specimen for evaluating metal ion release from metal-on-metal joint arthroplasty.   Chromium in red blood cells is used to investigate or monitor potential chromium exposure and is preferred particularly for the assessment of hexavalent chromium exposure.

Serum/Plasma

Concentration of chromium in serum is one of the most common measures of chromium status,  whether deficiency or overload. Serum assays are appropriate to use for evaluating metal ion release from metal-on-metal joint arthroplasty when whole blood assays are not available.  Elevated plasma chromium levels may be a good indicator of exposure and indicate recent dietary intake. 

Urine

The level of chromium in urine is one of the most common measures of chromium status  and may be used to monitor short-term exposure (other than that from metal-on-metal joint implants).

Monitoring

The U.S. Food and Drug Administration recommends cobalt and chromium metal ion testing be considered in symptomatic patients with metal-on-metal hip replacements.  While the FDA found insufficient evidence to recommend testing in asymptomatic patients,  the Medicines and Healthcare products Regulatory Agency (MHRA) recommends testing for every patient with metal-on-metal hip replacements on the following schedule :

  • Symptomatic patients: annually while the device remains implanted
  • Asymptomatic patients with all stemmed total hip replacements or resurfacing devices without a 10A Orthopaedic Data Evaluation Panel (ODEP) rating: annually for the first 5 years, twice a year to 10 years, and three times a year thereafter
  • Asymptomatic patients with resurfacing devices with 10A ODEP rating: at the first year, once at 7 years, and three times a year thereafter

There is no accepted cutoff value for whole blood metal levels that either predicts outcome or indicates revision is necessary; however, the MHRA suggests that a measurement of ≥7 ppb (119 nmol/L cobalt or 134.5 nmol/L chromium) in one or both metals indicates the need for further investigation.  Whole blood is the preferred specimen.  

Cobalt

Cobalt, a component of vitamin B12, is a natural element that is essential for blood and DNA production and nerve health. In excess, however, it negatively affects the lungs and heart. Dietary cobalt toxicity is rare; toxicity is more likely to occur in an occupational setting where cobalt is released into the air in high concentrations. Exposure can also be caused by metal-on-metal arthroplasty and athletic salts. Cardiomyopathy is common, especially in heavy beer drinkers, as cobalt interacts with ethanol, but the mechanism of action is not fully elucidated. Industrially, cobalt is used in the manufacturing of magnets, tools, aircraft engines, and hip and knee prostheses.

Biologic function

Red blood cell production, DNA production, nervous system performance

Sources

Fish, nuts, green vegetables, cereals, drinking water, metal-on-metal prosthetic implants

Signs and symptoms of deficiency

Not reported in humans

Signs and symptoms of excess

Hyperthyroidism, goiter, cardiomyopathy, allergic dermatitis, pulmonary fibrosis, cough and dyspnea, decreased iodine uptake

Recommended daily adult intake

Included in 1.5 µg of vitamin B12 daily

Indications for Testing

Symptomatic patients with a known or suspected source of exposure should be tested. Patients with metal-on-metal joint replacements, in particular, are at risk for release of metal debris, which can cause periprosthetic soft tissue reactions and chromium and cobalt toxicity and can result in neurologic impairment, cardiomyopathy, and hypothyroidism. See Monitoring.

Laboratory Testing

Diagnosis

Blood

Either whole blood or erythrocytes may be used in the assessment of occupational exposure or toxic ingestion. Whole blood is the preferred specimen for evaluating metal ion release from metal-on-metal joint arthroplasty.   Elevated cobalt levels in red blood cells indicate long-term exposure. 

Serum/Plasma

Serum or plasma can be used to assess occupational exposure or toxic ingestion. Most serum/plasma cobalt tests include free ionized cobalt and free and protein-bound soluble cobalt measurements; elevated concentrations indicate recent exposure.  Serum assays are appropriate to use for evaluating metal ion release from metal-on-metal joint arthroplasty when whole blood assays are not available. 

Urine

Urine cobalt measurements are best for determining recent, acute exposure, as the majority of cobalt is eliminated in urine 2-8 days after ingestion. 

Monitoring

The U.S. Food and Drug Administration recommends cobalt and chromium metal ion testing be considered in symptomatic patients with metal-on-metal hip replacements.  While the FDA found insufficient evidence to recommend testing in asymptomatic patients,  the Medicines and Healthcare products Regulatory Agency (MHRA) recommends testing for every patient with metal-on-metal hip replacements on the following schedule. 

  • Symptomatic patients: annually while the device remains implanted
  • Asymptomatic patients with all stemmed total hip replacement or resurfacing devices without a 10A Orthopaedic Data Evaluation Panel (ODEP) rating: annually for the first 5 years, twice a year to 10 years, and three times a year thereafter
  • Asymptomatic patients with resurfacing devices with 10A ODEP rating: at the first year, once at 7 years, and three time a year thereafter

There is no accepted cutoff value for whole blood metal levels that either predicts outcome or indicates revision is necessary; however, the MHRA suggests that a measurement of ≥7ppb (119 nmol/L cobalt or 134.5 nmol/L chromium) in one or both metals indicates the need for further investigation.  Whole blood is the preferred specimen.  

Copper

Copper is present throughout the environment and is used for wires and pipes, in brass and bronze fixtures, and as a textiles preservative. It is an essential element for all plants and animals. Although copper is dietarily necessary in a small amount for healthy nerves, bones, and collagen, ingesting or breathing in too much can cause vomiting and diarrhea or nose and throat irritation. It can also damage the liver and kidneys.

Excess copper body burden may also be a result of an inherited disorder called Wilson disease, which causes copper to accumulate in the liver and brain rather than being eliminated through bile and can be fatal if untreated. Conversely, Menkes disease is a genetic disorder that reduces copper bioavailability, resulting in symptoms of deficiency.

Biologic function

Integral part of numerous enzyme systems, including amine oxidase, ferroxidase, superoxide dismutase, dopamine hydroxylase

Sources

Shellfish, liver, nuts, legumes, bran, organ meats

Signs and symptoms of deficiency

Anemia, osteopenia, degenerative changes in aortic elastin, growth retardation, hair pigment changes, cerebral and cerebellar degeneration, Menkes disease

Signs and symptoms of excess

Nausea, emesis, diarrhea, hemolytic anemia, neurodegeneration, hepatic failure, Wilson disease

Toxicity more likely at intake of 10,000 μg/day

Recommended dietary allowance

900 μg/day for adults 

340-890 μg/day for children (age dependent) 

Indications for Testing

Deficiency

Individuals with symptoms of copper deficiency, including slow growth (especially in young children), anemia, and osteopenia, should be considered for copper deficiency testing. Patients who have had bariatric surgery are at increased risk for symptoms of nutrient deficiencies.

Toxicity

Individuals with progressive neurologic dysfunction, especially in association with liver disease, should be tested for copper excess that may be related to Wilson disease, unless a source of exposure is known.

Laboratory Testing

Diagnosis

Panel testing is preferred to diagnose conditions of copper overload in symptomatic patients or individuals with a family history of Wilson disease. For diagnostic testing recommendations specific to Wilson disease, see the Wilson Disease topic.

Serum/Plasma

Serum/plasma copper is a traditional marker for copper status; levels are decreased in severe copper deficiency. But serum/plasma copper may not be a reliable marker for mild deficiency, as circulating concentrations are affected by age, infection, inflammation, cancer, and pregnancy.  In situations of copper overload, serum ceruloplasmin is usually low, and free copper (direct) is usually high. Serum free (direct) copper testing is preferred to monitor response to copper-reducing therapies.

Ceruloplasmin

Ceruloplasmin is a protein in the blood that carries copper; it is a traditional marker for copper status. But like serum/plasma copper, ceruloplasmin copper concentrations may be affected by conditions other than deficiency. Testing of ceruloplasmin may be used as an initial screening test in Wilson disease or copper transport disorders, but panel testing that includes copper, free copper (direct), and ceruloplasmin is preferred.

Urine

Copper testing of either random urine or 24-hour urine may be useful in the assessment of overload, but validity is subject to interindividual variability. 

Liver

Liver copper may also provide information on copper status; it is especially useful when related serum or urine assessments are inconclusive. Levels are increased in Wilson disease. 

Blood

Erythrocyte testing may be useful for exposure monitoring or investigation, but it is not recommended for clinical diagnosis.

Iodine

Iodine is an essential nutritional element for proper thyroid function and development. Deficiency can cause goiter in adults and brain damage and mental retardation in children and fetuses. Excess iodine is typically excreted from the body, so toxic levels are usually a result of drugs, radioactive iodine uptake tests, and iodine-containing sterilizers.

Biologic function

Supports proper thyroid function

Sources

Seaweed, seafood, dairy, eggs, iodized salt

Signs and symptoms of deficiency

Goitrous hypothyroidism, delayed growth, weight gain, fatigue, weakness

Signs and symptoms of excess

Hyperthyroidism, thyroid gland malignancies, abdominal pain, diarrhea, fever

Recommended dietary allowance

150 μg/day for adults and children >13 years  

90-120 μg/day for children (age dependent) 

110-130 μg/day for infants (age dependent) 

Indications for Testing

Individuals with signs of either deficiency or excess iodine should be considered for testing. Dysfunction of the thyroid gland is a principle indicator.

Laboratory Testing

Diagnosis

Urine

The majority of excess iodine is excreted in urine, making urine iodine testing ideal for determining nutritional status, especially across populations. Because iodine intake varies from day to day, 24-hour urine testing is a more accurate measure and preferred over random urine testing; however, accuracy of 24-hour urine testing is affected by low protein intake and high creatinine output. 

Serum

Serum testing is recommended for determining iodine excess and monitoring overload in patients on iodine-containing medications. For testing specific to thyroid function, see Thyroid Disease topic.

Iron

Iron is distributed throughout the body, mainly into hemoglobin and also ferritin and hemosiderin; it is transferred from organ to organ by a complex called transferrin. Iron deficiency occurs more frequently than deficiency of any other micronutrient.  Signs and symptoms of iron deficiency anemia appear when body stores are depleted. Acute toxicity is characterized by constipation, vomiting, and diarrhea and is more likely to occur in children. Chronic toxicity is most likely a result of hereditary hemochromatosis but is otherwise rare. 

Biologic function

Production of hemoglobin

Sources

Shellfish, green leafy vegetables (eg, spinach), legumes, red meat

Signs and symptoms of deficiency

Anemia, fatigue, weakness, pallor, dizziness, fainting

Signs and symptoms of excess

Constipation, diarrhea, nausea, hemochromatosis

Recommended dietary allowance

Men and postmenopausal women: 8 mg/day

Premenopausal women: 18 mg/day

Children: 7-15 mg/day (age and sex dependent)

Indications for Testing

Individuals with signs of either iron deficiency or excess should be considered for testing. The most common indicator of deficiency is anemia and its corresponding symptoms:

  • Fatigue
  • Shortness of breath
  • Pallor
  • Dizziness
  • Fainting

Hemochromatosis is characterized by the classic triad of symptoms:

  • Bronzing of skin
  • Cirrhosis
  • DM

Laboratory Testing

Diagnosis

Several laboratory testing options are available to help identify iron deficiency or overload. For testing recommendations specific to iron deficiency anemia, see Iron Deficiency Anemia topic. For testing and monitoring of iron overload as a result of hemochromatosis, see Hemochromatosis topic. For testing for beta (β)-thalassemia, the most common cause of secondary iron overload, see Thalassemias topic.

Serum Iron

A serum iron measurement indicates the amount of iron bound to serum transferrin and does not include iron contained in serum as free hemoglobin. Serum iron concentrations are often decreased in patients with iron deficiency anemia as well as in those with inflammatory disorders; but concentrations naturally decrease throughout the day, so results require careful interpretation. Levels are increased with iron-loading disorders and after iron intake.

Total Iron-Binding Capacity

Total iron-binding capacity is a measurement of the greatest amount of iron that transferrin can bind. In iron deficiency, transferrin saturation, determined by plasma iron to total iron-binding capacity ratio, is low because synthesis increases to maximize iron delivery.

Transferrin

Serum transferrin may be a better biomarker than iron-binding capacity because it is not affected by inflammatory diseases, which can yield false-negative results.

Soluble Transferrin Receptor

Soluble transferrin receptor testing can distinguish between iron deficiency anemia and anemia of chronic disease and can identify iron deficiency anemia in patients with inflammatory conditions in whom ferritin is increased.  It is also a useful marker because it corresponds more closely with the depletion and normalization of iron stores. 

Ferritin

Serum ferritin is an acute phase reactant and concentrations are affected by inflammation, alcohol use,  and obesity. However, in the absence of inflammation, measurement of serum ferritin is the most powerful test for iron deficiency. 

Erythrocyte Zinc Protoporphyrin

Erythrocyte zinc protoporphyrin is an indicator of abnormal heme synthesis and is helpful in primary screening for basic iron deficiency; in combination with soluble transferrin receptor testing, it is particularly useful for monitoring iron supplement therapy. 

Other Testing

Liver tissue can be useful in confirming hepatic iron overload, particularly in individuals with hemochromatosis and no common HFE gene variants, but less invasive iron testing should be used as an initial approach to diagnosis. Similarly, bone marrow staining can be used to assess iron status by examining the amount of hemosiderin in the reticulum cells. 

Lead

Lead poisoning or lead toxicity generally occurs either in childhood or because of occupational exposure. Lead exposure in children can result in critical conditions, including brain damage, nervous system damage, developmental delay, and hearing and speech problems.  In adults, lead exposure can cause adverse reproductive outcomes in women, hypertension, renal damage, and cognitive dysfunction.  Lead poisoning can also disturb heme synthesis and cause symptoms similar to those of porphyrin disorders, including abdominal pain, nausea, and rapid heart rate. Aminolevulinic acid, erythrocyte porphyrin, and zinc protoporphyrin can be used as biomarkers to differentiate a lead poisoning effect.  See the Porphyrias topic for testing specific to porphyrin disorders.

Biologic function

No human physiologic function

Sources

Shellfish, green leafy vegetables (eg, spinach), legumes, red meat

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Hypertension, renal damage, cognitive dysfunction, spontaneous abortion (miscarriage)

Recommended daily adult intake

Not applicable

Indications for Testing

Testing is appropriate for adults with a risk of exposure, known exposure, or suspected occupational exposure. Children at greater risk include those who are younger than 6 years and those who live in older housing; children of some racial and ethnic groups are also at higher risk. 

Laboratory Testing

Diagnosis

Blood

The best way to measure lead exposure is with a venous blood lead test.  Blood from capillaries is recommended for routine testing in pediatric populations. A safe blood lead level (BLL) has not been identified for children. Confirmatory testing should be performed within 1-3 months for children with a BLL above the reference value or within 48 hours if the BLL is ≥45 µg/dL.  Management is recommended for adults with a BLL ≥5 µg/dL. 

Age

Concentration (µg/dL)

Commentsa

All ages

5-9.9

Adverse health effects are possible, particularly in children <6 years of age and pregnant women. Discuss health risks associated with continued lead exposure. For children and women who are or may become pregnant, reduce lead exposure.

All ages

10-19.9

Reduced lead exposure and increased biological monitoring are recommended.

All ages

20-69.9

Removal from lead exposure and prompt medical evaluation are recommended. Consider chelation therapy when concentrations exceed 50 µg/dL and symptoms of lead toxicity are present.

<19 years of age

>44.9

This is a critical level. Immediate medical evaluation is recommended. Consider chelation therapy when symptoms of lead toxicity are present.

>19 years of age

>69.9

This is a critical level. Immediate medical evaluation is recommended. Consider chelation therapy when symptoms of lead toxicity are present.

aThresholds and time intervals for retesting, medical evaluation, and response vary by state and regulatory body. Contact your State Department of Health and/or applicable regulatory agency for specific guidance on medical management recommendations.

Source: CDC Response to Advisory Committee on Childhood Lead Poisoning Prevention Recommendations in “Low Level Lead Exposure Harms Children: A Renewed Call of Primary Prevention 

Urine

Urine lead testing may be useful in the assessment of chronic lead exposure or in monitoring chelation therapy, but blood is preferred for routine lead exposure testing.

Screening

The Centers of Disease Control and Prevention recommends that all children should have one BLL test performed between 12 and 24 months; Medicaid-enrolled children are required to be tested at 12 months and at 24 months.  The American Academy of Pediatrics recommends risk assessment or screenings as appropriate at 6, 9, 12, and 18 months and annually from 2-6 years of age.   The United States Preventive Services Task Force (USPSTF) found insufficient evidence to recommend or discourage screening of elevated blood lead levels in asymptomatic pregnant women and asymptomatic children younger than 6 years of age. 

Monitoring

Children with a BLL ≥5 µg/dL must be monitored until environmental conditions are resolved. 

Lead-exposed workers should have a baseline BLL determined at placement and be monitored based on BLL :

  • <10 µg/dL
    • Perform BLL test every month for the first 3 months after placement or after being placed in a higher-exposure task, then every 6 months.
    • If BLL increases ≥5 µg/dL, evaluate exposure and increase monitoring frequency if necessary.
    • Women with a BLL 5-9 µg/dL who are pregnant or may become pregnant should reduce lead exposure.
  • 10-19 µg/dL
    • Perform BLL test every 3 months.
    • Evaluate exposure and consider removal from exposure.
    • If three BLLs are <10 µg/dL, test every 6 months.
  • ≥20 µg/dL
    • If BLL is ≥30 µg/dL, remove from exposure.
    • If BLL remains 20-29 µg/dL after 4 weeks, remove from exposure.
    • Perform monthly testing of BLLs.
    • If two monthly tests report a BLL <15 µg/dL, consider a return to work.

Magnesium

Symptomatic magnesium deficiency is rare, but people at risk for magnesium inadequacy are those with gastrointestinal disease, type 2 DM, and alcohol dependence.  Insufficient levels are associated with high blood pressure, osteoporosis, and migraines.  The kidneys eliminate any excess dietary magnesium in urine, but the use of supplements, notably laxatives and antacids that contain magnesium, can cause toxicity, resulting in low blood pressure, nausea, urine retention, and possible cardiac arrest. Hypermagnesemia is an abnormally high level of magnesium specifically in serum. In clinical practice it is most often caused by the treatment for preeclampsia or eclampsia in pregnant women.  Hypermagnesemia can also occur in patients with renal failure, milk-alkali syndrome, or tumor lysis syndrome. Hypomagnesemia is common in hospitalized patients and in patients with acute or chronic illness.

Biologic function

Bone strength, heart rate regulation, nerve and muscle health

Sources

Nuts, green leafy vegetables, whole grains, tap water

Signs and symptoms of deficiency

Lack of appetite, fatigue and weakness, vomiting leading to muscle cramps, seizures, coronary spasms

Signs and symptoms of excess

Low blood pressure, nausea, depression, difficulty breathing, irregular heart beat

Recommended dietary allowance

Children: 30-410 mg/day (age and sex dependent) 

Adults: 310-420 mg/day (age and sex dependent) 

Indications for Testing

Testing for magnesium status should be performed in conjunction with a clinical assessment. Indications for magnesium testing include

Laboratory Testing

Diagnosis

Serum/Plasma

Serum magnesium concentration is the most common and available method to measure magnesium status; it is preferred for routine screening. It does not, however, correlate with total body stores or concentrations in tissue. 

Blood

Erythrocyte measurements may be useful in the assessment of tissue stores of magnesium, but no test alone is diagnostic.

Urine

Urine measurements may provide information on magnesium status, but no test alone is diagnostic. 

Manganese

Manganese is an essential trace element found in most foods, but excess can cause brain damage. It is often used in pesticides and steel manufacturing and as a fuel additive. Occupational exposure poses a risk for nervous system damage, neurologic effects such as bradykinesia (slow movement), and lung irritation.

Biologic function

Bone metabolism, enterohepatic circulation

Sources

Groundwater, whole grains, beans, nuts, tea

Signs and symptoms of deficiency

Coagulopathy, dermatitis

Signs and symptoms of excess

Manganism (neurotoxic condition) characterized by tremors, abnormal gait, and facial muscle spasms

Adequate daily intake

Children: 1.2-2.2 mg/day (age and sex dependent) 

Adults: 1.8 mg/day for women, 2.3 mg/day for men 

Indications for Testing

Individuals with a known or suspected source of exposure and corresponding symptoms should be tested for manganese exposure.

Laboratory Testing

Diagnosis

Most laboratory testing is limited in measuring past exposure, as manganese is excreted from the body within days. 

Blood

Both whole blood testing and erythrocyte testing may be useful as reasonable indicators of recent, active manganese exposure and provide modest indicators for distinguishing exposed from nonexposed individuals. Whole blood is recommended for monitoring potential manganese accumulation from total parenteral nutrition. It is not recommended for detecting long-term, low-dose manganese exposure; erythrocyte testing should be used instead. Although whole blood is more accurate than either plasma or serum, some patients with normal whole blood manganese levels have abnormal magnetic resonance images. 

Serum/Plasma

Serum and plasma tests are believed to assess dietary manganese intake but typically indicate only dramatic variations in intake.  Serum testing is not recommended for the assessment of manganese body stores.

Urine

Urine testing has limited utility in determining manganese exposure; it is most reliable only for severe depletion. 

Mercury

Mercury has three forms: organic mercury compounds (which accumulate in the food chain), inorganic mercury compounds, and elemental mercury. All three forms can accumulate in the kidneys, brain, and central nervous system. Symptoms of toxicity depend on the form, route of exposure, and duration of exposure and include changes in skin pigmentation, headaches, nausea and vomiting, and thrombocytopenia.   Mercury has several industrial applications, including use in thermometers, dental fillings, and vaccines.

Biologic function

No human physiologic function

Sources

Fish, shellfish, air, water, dental amalgams, thermometers, compact fluorescent light bulbs

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Acute: Headaches, vomiting, dyspnea, chest pain, fever, impaired pulmonary function, papular erythema

Chronic: tremors, gingivitis, erethism, headache, short-term memory loss, anorexia, paraesthesia, dysarthria, visual field constriction, blindness, hearing impairment

Recommended daily adult intake

Not applicable

Indications for Testing

Individuals with a known or suspected source of exposure and corresponding symptoms should be tested for mercury exposure. Fish consumption can elevate total whole blood mercury concentrations.  Clinical presentation after toxic exposure to organic mercury may include dysarthria, ataxia, and constricted vision fields with mercury blood concentrations from 20-50 µg/L.

Criteria for Diagnosis

An elevated whole blood or urinary mercury concentration is diagnostic for mercury exposure. A total whole blood mercury concentration ≥10 µg/L or a urinary mercury concentration ≥10 µg/L is an unusual level of exposure for a person with no known occupational exposure to mercury. 

A study reviewing data from the Centers for Disease Control and Prevention,  the U.S. Environmental Protection Agency, and the American Conference of Governmental Industrial Hygienists suggests that, for vigilance with respect to exposure sources (including occupational exposure and food ingestion) and reduction measures, the mercury limit should be 10.0 μg/L for blood mercury and 19.8 nmol Hg per mmol creatinine for urine mercury.  Clinical intervention is recommended at blood mercury concentrations ≥40 μg/L. 

Laboratory Testing

Diagnosis

Urine

Urinary mercury levels predominantly reflect acute or chronic elemental or inorganic mercury exposure but not organic mercury exposure, as organic mercury is eliminated in the stool and is not reflected in urine.   A 24-hour urine specimen is preferred.  Urine concentrations in unexposed individuals are typically <10 µg/L, and levels up to 20 µg/L are not associated with symptoms.  Urine concentrations of 30-100 µg/L from a 24-hour collection may be associated with subclinical neuropsychiatric symptoms and tremors, and concentrations >100 µg/L can be associated with overt neuropsychiatric disturbances and impaired kidney function. Urine is especially useful for monitoring chelation therapy.  Because mercury accumulates in the kidneys, mercury-urine concentrations may also be a better indicator of kidney burden  than concentrations in blood or hair.

Blood

Blood can be used to evaluate exposure to mercury of any form. Both dietary and nonoccupational exposure to organic mercury may contribute to an elevated total mercury result. Blood mercury predominantly reflects recent exposure and is most useful in the diagnosis of acute poisoning, as mercury has a half-life in blood of 3 days. Blood concentrations in unexposed individuals are usually <10 µg/L, but concentrations up to 20 µg/L are considered normal.  A blood concentration ≥50 μg/L is considered the threshold for symptoms of toxicity. 

Hair

Hair mercury concentration can be used as a biomarker of chronic exposure to organic mercury and can show exposure that has occurred over a long period of time; concentrations have been shown to be proportionate to blood mercury concentration.  However, because hair can absorb noningested environmental mercury, hair may not be accurate in certain circumstances.

Nickel

Nickel is found in all soil, meteorites, the ocean floor, and volcanic emissions. Nickle-containing food is the most common source of exposure, but exposure can also occur from handling nickel-containing coins, jewelry, and electronic devices. Up to 20% of the population is sensitive to nickel and subject to an allergic reaction that manifests as a skin rash. Higher-level exposure can occur from contact with nickel-processing industries. Nickel carbonyl, used in petroleum refining, is a highly toxic chemical. Symptoms of occupational exposure include chronic bronchitis, reduced lung function, inability to oxygenate blood, and lesions on organs. Soluble nickel compounds are more easily detected by testing than are less soluble compounds. 

Biologic function

Aids in iron absorption, increases hormonal activity, involved in lipid and glucose metabolism, improves bone strength

Sources

Tea, nuts, seeds, soy beans, legumes, cocoa, certain grains, certain canned foods, cigarettes

Signs and symptoms of deficiency

Slow growth, low hemoglobin concentrations, impaired glucose metabolism

Signs and symptoms of excess

Shortness of breath, headache, nausea, vomiting, rash (allergy)

Recommended daily adult intake

Not established 

Indications for Testing

Measurement of nickel is not recommended in asymptomatic individuals or individuals with a low likelihood of exposure.

Laboratory Testing

Diagnosis

Urine

Urine is the preferred specimen for the determination of exposure.

Serum

Serum nickel concentrations may be informative in the investigation of toxic exposure.

Selenium

Selenium is a required element for antioxidant balance, thyroid hormones, and immunity ; but excess can cause selenosis, which is characterized by nerve damage. The range for normal selenium levels is small.  Selenium is used in the electronics and glass industries and as a pigment. In patients who undergo bariatric surgery, deficiency is present in as many as 20% postoperatively.

Biologic function

Component of the enzyme glutathione peroxidase

Helps protect proteins, cell membranes, lipids, and nucleic acids from oxidant molecules

Sources

Seafood, kidney and liver meats, cereals

Signs and symptoms of deficiency

Cardiomyopathy and heart failure (Keshan disease), striated muscle degeneration, deforming arthritis (Kashin-Bek disease)

Signs and symptoms of excess

Alopecia, nausea, emesis, dermatitis, peripheral neuropathy

Recommended daily intake

Children: 20-55 mg/day (age dependent) 

Adults: 55 mg/day 

Indications for Testing

Individuals with signs or symptoms of either selenium deficiency or overload should be considered for selenium status testing. Patients having had bariatric surgery are at increased risk for symptoms of nutrient deficiencies.

Laboratory Testing

Diagnosis

Urine

Urine selenium is the preferred indicator of selenium status, as urinary excretion of excess selenium manages body content.

Serum/Plasma

Because selenium is transported to the organs in plasma and increases quickly with intake, plasma or serum is used most often to evaluate short-term dietary consumption. 

Blood

Erythrocyte testing is most appropriate for the assessment of selenium tissue stores, but urine is preferred to evaluate deficiency or toxicity.

Thallium

Thallium is a metal found in small amounts in soil but has no physiologic function in humans. Most thallium exposure is a result of food consumption, cigarette smoking, or workplace inhalation. Thallium is used in electronic devices and for semiconductors.

Biologic function

No human physiologic function

Sources

Fish, shellfish

Signs and symptoms of deficiency

Not applicable

Signs and symptoms of excess

Vomiting, hair loss, numbness of fingers and toes, lung, heart, liver, and kidney problems

Recommended dietary allowance

Not applicable

Indications for Testing

Individuals with a known or suspected source of exposure and corresponding symptoms should be tested for thallium exposure.

Laboratory Testing

Diagnosis

Urine

Urine thallium testing is useful for determining chronic thallium exposure.

Blood

Blood may be an indicator of recent, acute exposure, but thallium does not stay in the blood long and is quickly distributed to body tissues.

Zinc

Zinc is present in air, soil, water, and all foods, as well as many commercial products. In small quantities it is an essential nutritional element for metabolism, immunity, and the cell life cycle; in large quantities it can cause abdominal pain (from acute exposure) or secondary hypocupremia (from chronic exposure).

Biologic function

Integral component of metalloenzymes

Synthesizes and stabilizes proteins, DNA, and RNA

Sources

Meat, shellfish, nuts, legumes

Signs and symptoms of deficiency

Growth retardation, alopecia, dermatitis, diarrhea, failure to thrive, congenital malformations

Signs and symptoms of excess

Reduced copper absorption, gastritis, fever, nausea, emesis, metal fume fever;

300-600 mg/day may induce sideroblastic anemia

Recommended dietary allowance

Children: 3-11 mg/day (age and sex dependent) 

Adults: 8 mg/day (women); 11 mg/day (men) 

Indications for Testing

There is no clear indication for zinc status assessment ; however, individuals with signs or symptoms of either zinc deficiency (particularly slow growth in children) or overload can be considered for zinc status testing.

Laboratory Testing

Diagnosis

Serum/Plasma

Serum zinc is the most frequently used biomarker for zinc status, particularly acute deficiency. However, serum testing is limited in its ability to detect marginal deficiency and is affected by daily fluctuations of zinc and inflammation caused by other diseases. 

Urine

Urine zinc is an insensitive biomarker, but it may be helpful as an indicator of acute toxicity. Urinary excretion correlates to body stores. 

Blood

Both whole blood and erythrocyte testing have limited utility as indicators of deficiency.

ARUP Laboratory Tests

Aluminum

Serum Assay

Preferred test for routine screening

Use to assess aluminum toxicity due to dialysis

Urine Assay

Preferred test for chronic exposure

Antimony

Blood Assay

Use to assess recent antimony exposure

Arsenic

Urine Assays

Preferred test for assessing acute or chronic arsenic exposure

Differentiates between toxic inorganic and methylated species as well as benign organic forms

Use to identify species of arsenic

Blood Assay

Useful for recent (<24 hours) and/or large-dose arsenic exposure

Hair Assay

May be useful in the evaluation of past exposure to arsenic in situations where concern over exposure is high, but urine results are negative

Panel Tests

Useful in the assessment of acute and chronic exposure to select heavy metals

Components: arsenic, arsenic fractionation, lead, mercury

Components: arsenic, arsenic fractionation, lead, mercury

Components: arsenic, cadmium, lead, mercury

Components: arsenic, cadmium, copper, lead, mercury, zinc

Useful in the assessment of recent exposure to select heavy metals

Components: arsenic, lead, mercury

Components: arsenic, cadmium, lead, mercury

Beryllium

Beryllium Lymphocyte Proliferation

Recommended test for identifying beryllium sensitization and CBD

Serum

Confirm an exposure to beryllium

Bismuth

Blood Assay

Useful to access acute or chronic bismuth exposure

Cadmium

Urine Assays

Assess chronic exposure and body burden

Blood Assay

Assess acute toxicity

OSHA Test

Occupational exposure monitoring

Includes both cadmium blood and urine

Panel Tests

Useful in the assessment of acute and chronic exposure to select heavy metals

Components: arsenic, cadmium, lead, mercury

Components: arsenic, cadmium, copper, lead, mercury, zinc

Useful in the assessment of recent exposure to select heavy metals

Components: arsenic, cadmium, lead, mercury

Chromium

Blood Assay

Investigate or monitor chromium exposure

Preferred test for hexavalent chromium exposure

Serum Assay

May be useful in the assessment of deficiency or overload

Acceptable test for evaluating metal ion release from metal-on-metal joint arthroplasty

Urine Assay

Monitor short-term exposure

Cobalt

Blood Assay

Preferred test for evaluating metal ion release from metal-on-metal joint arthroplasty

Assess occupational exposure or toxic ingestion

Serum/Plasma Assay

Assess occupational exposure or toxic ingestion

Urine Assay

Assess acute exposure

Copper

Serum/Plasma Assays

Useful in the assessment of deficiency or overload

May be useful in the assessment of copper overload or response to copper-reducing therapies

Directly measures the free (nonceruloplasmin bound) fraction of copper

Ceruloplasmin Assay

May be used as initial screening test in Wilson disease or copper transport disorders

Urine Assays

Useful in the assessment of overload

Liver Assay

May be useful when related serum or urine assessments are inconclusive

Blood Assay

May be useful for exposure monitoring or investigation

Not recommended for clinical diagnosis

Heavy Metals Panel Test

Useful in the assessment of acute and chronic exposure to select heavy metals

Components: arsenic, cadmium, copper, lead, mercury, zinc

Iodine

Urine Assay

Recommended for the assessment of iodine nutritional statusa

Serum Assay

Recommended for determination of iodine excess and monitoring iodine overload in patients administered iodine-containing medicationsa

aTest reports total iodine but does not determine species

Iron

Serum/Plasma Assays

Aid in the diagnosis of iron deficiency anemia and iron overload

Aid in the diagnosis of iron deficiency anemia and iron overload

Includes calculated transferrin saturation

Aid in the diagnosis of iron deficiency anemia and iron overload

Distinguish iron-deficiency anemia from anemia from chronic disease

Aid in the diagnosis of iron deficiency anemia and iron overload

Monitor treatment of hemochromatosis

Blood Assay

Indicate chronic exposure to lead, primarily in industrial setting

Other Testing

Useful in confirming hepatic iron overload, particularly in individuals with hemochromatosis and no common HFE variants

Use to detect iron deficiency anemia, hemochromatosis, and hemosiderosis

Lead

Blood Assays

Recommended for routine testing for lead exposure

Recommended for routine testing for lead exposure in pediatric populations

Recommended for assessment of industrial lead exposure in adults

Urine Assays

Assess chronic lead exposure or monitor chelation therapy

Panel Tests

Useful in the assessment of acute and chronic exposure to select heavy metals

Components: arsenic, arsenic fractionation, lead, mercury 

Components: arsenic, arsenic fractionation, lead, mercury 

Components: arsenic, cadmium, lead, mercury

Components: arsenic, cadmium, copper, lead, mercury, zinc

Useful in the assessment of recent exposure to select heavy metals

Components: arsenic, lead, mercury

Components: arsenic, cadmium, lead, mercury

Other Testing

Determine effects of lead poisoning

Magnesium

Serum/Plasma Assay

Preferred test to assess magnesium deficiency

Blood Assay

Assess tissue stores

Urine Assay

Assess tissue stores

Other Testing

Assess tissue stores

Manganese

Blood Assays

Reasonable indicator of recent, active exposure

Modest indicator for distinguishing exposed from nonexposed individuals

Recommended for monitoring potential accumulation with total parenteral nutrition

Reasonable indicator of recent, active exposure

Modest indicator for distinguishing exposed from nonexposed individuals

May be useful in long-term, low-dose manganese exposure

Serum/Plasma Assay

Reasonable indicator of recent, active exposure

Modest indicator for distinguishing exposed from nonexposed individuals

Urine Assay

Limited utility in determining exposure

Mercury

Urine Assays

Preferred test for chronic mercury exposure

May be useful in monitoring chelation therapy

May be useful in the assessment of acute or chronic exposure and/or in monitoring chelation therapy

Blood Assay

Preferred test for acute mercury exposure (the provided reference interval relates to inorganic mercury concentrations)

Panel Tests

Useful in the assessment of acute and chronic exposure to select heavy metals

Components: arsenic, arsenic fractionation, lead, mercury

Components: arsenic, arsenic fractionation, lead, mercury

Components: arsenic, cadmium, lead, mercury

Components: arsenic, cadmium, copper, lead, mercury, zinc

Useful in the assessment of recent exposure to select heavy metals

Components: arsenic, lead, mercury

Components: arsenic, cadmium, lead, mercury

Nickel

Urine Assay

Urine is the preferred specimen for the determination of exposure

Serum Assay

Serum nickel may be informative in the investigation of toxic exposure

Selenium

Urine Assay

Preferred for toxicity and deficiency

Serum/Plasma Assay

Assess recent intake

Blood Assay

Assess tissue stores

Thallium

Urine Assay

Biomarker of chronic exposure

Blood Assay

Biomarker of acute exposure

Zinc

Serum/Plasma Assay

Acute deficiency

Urine Assay

Acute toxicity

Blood Assays

Limited utility as an indicator of deficiency

Panel Test

Useful in the assessment of acute and chronic exposure to select heavy metals

Components: arsenic, cadmium, copper, lead, mercury, zinc

Medical Experts

Contributor

References

  1. ATSDR - Aluminum

    Agency for Toxic Substances and Diseases Registry. Aluminum. U.S. Department of Health and Human Services. [Last update: Aug 2018; Accessed: Oct 2018]
    Online
  2. ATSDR - Antimony

    Agency for Toxic Substances and Diseases Registry. Antimony. U.S. Department of Health and Human Services. [Last update: Jan 2015; Accessed: Oct 2018]
    Online
  3. ATSDR - Cadmium

    Agency for Toxic Substances and Diseases Registry. Cadmium. U.S. Department of Health and Human Services. [Last update: Mar 2015; Accessed: Oct 2018]
    Online
  4. ATSDR - Chromium

    Agency for Toxic Substances and Diseases Registry. Chromium. U.S. Department of Health and Human Services. [Last update: Sep 2016; Accessed: Oct 2018]
    Online
  5. ATSDR - Iodine

    Agency for Toxic Substances and Diseases Registry. Iodine. U.S. Department of Health and Human Services. [Last update: Mar 2011; Accessed: Oct 2018]
    Online
  6. CDC - Lead

    U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Lead. [Last updated: Feb 2015; Accessed: Sep 2017]

    Online
  7. ATSDR - Manganese

    Agency for Toxic Substances and Diseases Registry. Manganese. U.S. Department of Health and Human Services. [Last update: Mar 2014; Accessed: Oct 2018]
    Online
  8. ATSDR - Nickel

    Agency for Toxic Substances and Diseases Registry. Nickel. U.S. Department of Health and Human Services. [Last update: Mar 2011; Accessed: Oct 2018]
    Online
Additional Resources
  • ATSDR - Beryllium

    Agency for Toxic Substances and Diseases Registry. Beryllium. U.S. Department of Health and Human Services. [Last updated: Jun 2015; Accessed: Jan 2019]
    Online
  • Resources from the ARUP Institute for Clinical and Experimental Pathology®