Chemistry Ch 27: Trace Elements

A trace element is considered essential when:

A. It is always present in high concentrations in tissues

B. Deficiency causes impairment and replacement corrects the abnormality

C. It is required only during childhood

D. It is never toxic

Deficiency causes impairment and replacement corrects the abnormality

Which trace element is transported primarily by transferrin and albumin?

A. Zinc

B. Chromium

C. Mercury

D. Selenium

Chromium

Which trace element is incorporated into ceruloplasmin in the liver?

A. Iron

B. Copper

C. Zinc

D. Selenium

Copper

Wilson disease is characterized by:

A. Iron accumulation

B. Zinc accumulation

C. Copper accumulation

D. Selenium deficiency

C. Copper accumulation

Kayser-Fleischer rings are associated with:

A. Lead poisoning

B. Wilson disease

C. Hemochromatosis

D. Menkes disease

B. Wilson disease

The preferred specimen for chronic arsenic exposure is:

A. Serum

B. Whole blood

C. Urine

D. Saliva

C. Urine

Organic arsenic is generally:

A. Highly toxic

B. Lethal

C. Relatively nontoxic

D. Stored indefinitely

C. Relatively nontoxic

Which toxic metal commonly produces peripheral neuropathy, anemia, and renal disease?

A. Zinc

B. Selenium

C. Lead

D. Chromium

Lead

The trace element whose toxicity resembles Parkinson disease is:

A. Zinc

B. Copper

C. Manganese

D. Selenium

Manganese

Molybdenum is required for:

A. Hemoglobin synthesis

B. Xanthine oxidase

C. Insulin production

D. Vitamin D synthesis

B. Xanthine oxidase

Which trace element serves as an antioxidant and participates in thyroid hormone metabolism?

A. Zinc

B. Chromium

C. Selenium

D. Nickel

C. Selenium

A deficiency of selenium may lead to:

A. Cardiomyopathy

B. Night blindness

C. Rickets

D. Pellagra

Cardiomyopathy

Zinc deficiency commonly causes:

A. Growth retardation

B. Hypercalcemia

C. Polycythemia

D. Hyperpigmentation

A. Growth retardation

A patient has decreased taste perception and delayed skeletal maturation. Which deficiency is most likely?

A. Chromium

B. Zinc

C. Copper

D. Selenium

Zinc

Which vitamin deficiency causes scurvy?

A. Vitamin A

B. Vitamin D

C. Vitamin C

D. Vitamin E

Vitamin C

Which vitamin is required for synthesis of clotting factors II, VII, IX, and X?

A. Vitamin K

B. Vitamin C

C. Vitamin D

D. Vitamin A

A. Vitamin K

Prolonged antibiotic use most commonly causes deficiency of:

A. Vitamin A

B. Vitamin K

C. Vitamin E

D. Vitamin C

B. Vitamin K

Night blindness is characteristic of deficiency of:

A. Vitamin A

B. Vitamin D

C. Vitamin B12

D. Vitamin C

A. Vitamin A

The most common screening test for vitamin D status is:

A. 1,25(OH)₂D

B. 25(OH)D

C. Calcium

D. PTH

B. 25(OH)D

Pellagra is caused by deficiency of:

A. B1

B. B2

C. B3

D. B12

C. B3

The "4 Ds" of pellagra are:

A. Dermatitis, Diarrhea, Dementia, Death

B. Dermatitis, Diabetes, Dementia, Death

C. Depression, Dermatitis, Dementia, Death

D. Diarrhea, Diabetes, Dementia, Death

A. Dermatitis, Diarrhea, Dementia, Death

Beriberi results from deficiency of:

A. B12

B. B6

C. B1

D. B3

C. B1

Megaloblastic anemia and neural tube defects are associated with deficiency of:

A. Biotin

B. Folate

C. Riboflavin

D. Pantothenic acid

Folate

Intrinsic factor is necessary for absorption of:

A. Folate

B. B6

C. B12

D. Vitamin C

B12

A vegetarian with neurologic symptoms and elevated methylmalonic acid most likely has deficiency of:

A. Folate

B. Vitamin C

C. Vitamin B12

D. B1

Vitamin B12

Which pattern is most consistent with iron deficiency anemia?

A. ↑ Iron, ↑ Ferritin, ↓ TIBC

B. ↓ Iron, ↓ Ferritin, ↑ TIBC

C. ↓ Iron, ↑ Ferritin, ↓ TIBC

D. ↑ Iron, ↑ Ferritin, ↑ TIBC

B. ↓ Iron, ↓ Ferritin, ↑ TIBC

Which pattern suggests hereditary hemochromatosis?

A. ↑ Iron, ↑ Ferritin, ↓ TIBC, ↑ Saturation

B. ↓ Iron, ↑ Ferritin, ↓ TIBC

C. ↓ Iron, ↓ Ferritin, ↑ TIBC

D. Normal iron studies

A. ↑ Iron, ↑ Ferritin, ↓ TIBC, ↑ Saturation

Ferritin reflects:

A. Iron excretion

B. Iron transport

C. Iron storage

D. Hemoglobin concentration

C. Iron storage

Transferrin is:

A. Iron storage protein

B. Iron transport protein

C. Vitamin carrier

D. Clotting factor

B. Iron transport protein

Which disease classically presents with bronze skin, elevated iron, elevated ferritin, and high transferrin saturation?

A. Wilson disease

B. Iron deficiency anemia

C. Hemochromatosis

D. Selenium toxicity

C. Hemochromatosis

The most commonly used elemental analysis technique today is:

A. ELISA

B. ICP-MS

C. Electrophoresis

D. Nephelometry

B. ICP-MS

AAS stands for:

A. Automated Absorbance System

B. Atomic Absorption Spectroscopy

C. Automated Atomic Separation

D. Atomic Aerosol Spectrometry

B. Atomic Absorption Spectroscopy

AES quantifies elements by measuring:

A. Absorbed light

B. Emitted radiation

C. Electrical conductivity

D. Turbidity

Emitted radiation

What stopper tube is commonly used for trace element testing?

A. Lavender

B. Green

C. Royal blue

D. Gray

Royal blue

LC-ICP-MS is useful because it:

A. Measures glucose

B. Measures proteins

C. Performs elemental speciation

D. Measures vitamins only

Performs elemental speciation

A patient exposed to chromated copper arsenate has:

• Elevated urine arsenic

• Elevated methylated arsenic

• Low organic arsenic

Most likely diagnosis?

A. Seafood ingestion

B. Chronic inorganic arsenic exposure

C. Selenium toxicity

D. Wilson disease

Chronic inorganic arsenic exposure

Why is blood arsenic generally not preferred for chronic exposure testing?

A. Concentrations are too high

B. Arsenic is rapidly metabolized in blood

C. Blood cannot be analyzed

D. Results are always normal

Arsenic is rapidly metabolized in blood

A patient presents with:

• Diabetes

• Bronze skin

• Enlarged liver

• Elevated ferritin

• 80% transferrin saturation

Most likely diagnosis?

A. Iron deficiency

B. Wilson disease

C. Hereditary hemochromatosis

D. Zinc deficiency

Hereditary hemochromatosis

A patient has:

• Vegetarian diet

• Neurologic symptoms

• Borderline B12

• Elevated MMA

Diagnosis?

A. Folate deficiency

B. B12 deficiency

C. Vitamin C deficiency

D. Zinc toxicity

B12 deficiency

Why is MMA often more useful than serum B12 alone?

A. It directly reflects functional B12 status

B. B12 cannot be measured

C. MMA is always abnormal

D. MMA measures folate

It directly reflects functional B12 status

Transport Proteins

• 
  

• Chromium → transferrin + albumin

• Copper → albumin → ceruloplasmin

• Iron → transferrin

Classic Diseases

• 
  

• Wilson disease = Copper overload

• Menkes disease = Copper deficiency

• Hemochromatosis = Iron overload

• Chronic arsenic toxicity = neuropathy + skin lesions

• Manganese toxicity = Parkinson-like symptoms

• A = vision

• D = bones/calcium

• E = antioxidant/RBC protection

• K = clotting factors

Vitamins

• B1 = Beriberi

• B3 = Pellagra (4 Ds)

• B9 = Megaloblastic anemia + neural tube defects

• B12 = Pernicious anemia + neurologic disease

• C = Scurvy

Water-Soluble

• 
  

Iron Deficiency

• ↓ Iron

• ↓ Ferritin

• ↑ TIBC

• ↓ % Saturation

Hemochromatosis

• ↑ Iron

• ↑ Ferritin

• ↓ TIBC

• ↑ % Saturation

Anemia of Chronic Disease

• ↓ Iron

• ↑ Ferritin

• ↓ TIBC

• ↓ % Saturation

Iron Studies

Manganese

Involved in blood clotting

Arsenic

Found in insecticides and rat poison

Causes dermatitis

Chromium (toxic form)/ nickel

Plays a role in metabolism of fat, glucose, and cholesterol

Chromium

Influences enzymes involved with wound healing and growth

Zinc

Used to treat parasitic infections

Antimony

Results in basophilic stippling, anemia, and pancytopenia

Arsenic

Needed to reduce iron for heme synthesis

Copper

Higher in females than males

Cadmium

Results in tingling in the arms and legs

Mercury

Found in anti-dandruff shampoo

Selenium

Found in antacids, cosmetics, and antiperspirants

Aluminum