What does a copper level of 78 micrograms per deciliter (mcg/dl) indicate?

Interpretation of Serum Copper Level of 78 mcg/dL

A serum copper level of 78 mcg/dL falls within the normal reference range (typically 70-140 mcg/dL) and requires interpretation in the context of ceruloplasmin levels and clinical presentation, as total serum copper alone cannot distinguish between normal copper status, Wilson disease, or copper deficiency. 1

Critical Context: Why Total Serum Copper Is Misleading

• Total serum copper is paradoxically LOW in Wilson disease (a copper overload disorder) because 90% of circulating copper is bound to ceruloplasmin, which is decreased in Wilson disease. 1

• Your value of 78 mcg/dL could represent:

  • Normal copper status if ceruloplasmin is normal
  • Wilson disease if ceruloplasmin is low (the toxic "free copper" would be elevated despite normal total copper) 1
  • Borderline copper deficiency if ceruloplasmin is also low 2, 3

Essential Next Steps for Proper Interpretation

You must measure serum ceruloplasmin immediately to interpret this copper level correctly. 4, 5

If Ceruloplasmin Is Extremely Low (<5 mg/dL):

• This strongly suggests Wilson disease, regardless of your normal total copper level. 1
• Calculate non-ceruloplasmin bound (free) copper using the formula: serum copper (mcg/dL) minus [3 × ceruloplasmin (mg/dL)]. 1
• Free copper >25 mcg/dL indicates Wilson disease in untreated patients. 1
• Obtain 24-hour urinary copper excretion (>100 mcg/24 hours or >1.6 μmol/24 hours suggests Wilson disease). 1
• Arrange slit-lamp examination for Kayser-Fleischer rings. 1

If Ceruloplasmin Is Moderately Low (5-20 mg/dL):

• Calculate free copper as above. 1
• Consider Wilson disease carrier state (20% of heterozygotes have low ceruloplasmin but don't have disease). 1
• Consider copper deficiency, especially if you have gastrointestinal disease, bariatric surgery, or malabsorption. 2, 6
• Obtain 24-hour urinary copper to differentiate (low in deficiency, elevated in Wilson disease). 1

If Ceruloplasmin Is Normal (>20 mg/dL):

• Your copper status is likely normal. 3
• However, 10-20% of Wilson disease patients have normal ceruloplasmin, so if you have unexplained liver disease or neurological symptoms, Wilson disease is NOT excluded. 1

Clinical Red Flags Requiring Urgent Evaluation

Seek immediate evaluation if you have any of these symptoms:

• Unexplained liver disease (elevated transaminases, hepatomegaly, cirrhosis). 1
• Neurological movement disorders (tremor, dystonia, rigidity, ataxia). 1, 2
• Psychiatric symptoms combined with liver abnormalities. 1
• Unexplained anemia or leukopenia (suggests copper deficiency). 2, 6
• History of gastrointestinal surgery or malabsorption (high risk for copper deficiency). 2, 6

Common Pitfalls to Avoid

• Never rely on total serum copper alone for diagnosis—it is decreased in Wilson disease despite copper overload and cannot distinguish bound from toxic free copper. 1, 4
• Do not assume normal copper excludes Wilson disease—ceruloplasmin measurement and free copper calculation are mandatory. 1
• Ceruloplasmin is an acute phase reactant and may be falsely elevated during inflammation, potentially masking Wilson disease. 5
• In acute liver failure from any cause, serum copper may be markedly elevated due to sudden release from tissue stores, confounding interpretation. 1