What is the interpretation of these lab results showing elevated ferritin levels, mild liver enzyme elevations, and significant drop in vitamin B12 levels?

Lab Interpretation: Elevated Ferritin, Mild Transaminitis, and Vitamin B12 Decline

Overall Assessment

Your labs show mildly elevated ferritin (285 μg/L) with normal transferrin saturation (28%), mildly elevated liver enzymes (ALT 54, AST 47), and a significant drop in vitamin B12 from 1457 to 708 ng/L—this pattern strongly suggests secondary hyperferritinemia from an inflammatory or metabolic process rather than iron overload, and does not require iron-specific intervention. 1, 2

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Ferritin Interpretation

Key Finding: Not Iron Overload

• Your ferritin of 285 μg/L is below the threshold of concern for organ damage (>1000 μg/L) and well below levels associated with cirrhosis risk 3
• Transferrin saturation of 28% is normal (<45%), which effectively rules out hereditary hemochromatosis and primary iron overload disorders 3, 1, 2
• When TS <45% with elevated ferritin, the cause is almost always secondary: inflammation, liver disease, metabolic syndrome, or malignancy—not iron accumulation 1, 2

Most Likely Causes in Your Case

• Metabolic syndrome/NAFLD: Your ferritin elevation with normal TS, mildly elevated transaminases (ALT 54, AST 47), and normal glucose (92) fits the pattern of non-alcoholic fatty liver disease, where ferritin reflects hepatocellular injury and insulin resistance rather than iron overload 2, 4
• Low-grade inflammation: Ferritin is an acute phase reactant that rises with any inflammatory process, even subclinical ones 2, 5
• Chronic alcohol use (if applicable): This is one of the four most common causes of hyperferritinemia in routine practice 4

What You Don't Need

• No HFE genetic testing is indicated because your TS is normal (<45%) 3, 1
• No liver biopsy or MRI for iron quantification is needed at this ferritin level with normal TS 3, 6
• No therapeutic phlebotomy is warranted 7

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Liver Enzyme Elevation

Interpretation

• ALT 54 and AST 47 represent mild transaminitis (roughly 1.5x upper limit of normal) 3
• The AST/ALT ratio <1 suggests non-alcoholic liver disease rather than alcoholic liver disease 3
• Combined with ferritin 285 μg/L, this does not meet criteria for high cirrhosis risk (which requires ferritin >1000 μg/L plus elevated transaminases plus platelets <200) 3

Recommended Workup

• Screen for NAFLD risk factors: BMI, waist circumference, lipid panel, hemoglobin A1c 2
• Exclude viral hepatitis: Hepatitis B surface antigen, hepatitis C antibody 2
• Assess alcohol intake honestly with your provider 4
• Consider liver ultrasound to evaluate for hepatic steatosis 2

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Vitamin B12 Decline

Significant Drop Identified

• Your B12 dropped from 1457 ng/L to 708 ng/L between the two lab draws—a 51% decrease [@patient data@]
• While 708 ng/L remains in the normal range (typically >200 ng/L), this magnitude of decline warrants investigation 8
• Your homocysteine is normal (7 μmol/L), which argues against functional B12 deficiency [@patient data@]

Possible Explanations

• Cessation of B12 supplementation: If you were taking B12 supplements before the first draw and stopped, this would explain the decline
• Dietary changes: Reduced intake of animal products
• Medication effects: Metformin, proton pump inhibitors, or H2 blockers can impair B12 absorption
• Megaloblastic changes: In untreated B12 deficiency, red cell ferritin can be markedly elevated, though your MCV is normal (91.3) making this unlikely 8

Recommended Action

• Monitor B12 levels in 3-6 months to assess trajectory 2
• If levels continue to decline or symptoms develop (fatigue, neuropathy, cognitive changes), consider methylmalonic acid testing to assess for functional deficiency 2
• Your folate is low-normal (5.4 ng/mL), which may benefit from dietary optimization or supplementation [@patient data@]

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Other Notable Findings

Vitamin D Insufficiency

• Vitamin D 20.4 ng/mL is insufficient (optimal >30 ng/mL) [@patient data@]
• Recommend supplementation with 1000-2000 IU daily and recheck in 3 months

Low Zinc

• Zinc 0.5 mg/L is low (normal typically 0.66-1.10 mg/L) [@patient data@]
• Consider zinc supplementation 15-30 mg daily if dietary intake is inadequate

Mildly Low CO2

• CO2 19 mmol/L is slightly below normal range (typically 22-29) [@patient data@]
• This mild metabolic acidosis could reflect renal tubular acidosis, diarrhea, or dietary factors
• Recheck with venous blood gas if persistent or symptomatic

Lymphopenia

• Absolute lymphocyte count 1.40 × 10⁹/L (second draw: 2.145 × 10⁹/L) shows improvement but was initially borderline low [@patient data@]
• This can occur with viral infections, stress, or autoimmune conditions
• The improvement suggests a transient process

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Critical Pitfalls to Avoid

• Do not pursue iron overload workup when TS <45%—you will waste time and resources 1, 2
• Do not ignore the liver enzyme elevation—this requires evaluation for metabolic syndrome, viral hepatitis, and alcohol use 2, 4
• Do not assume ferritin elevation alone indicates iron overload—it is an acute phase reactant elevated in >90% of cases by non-iron causes 2, 4
• Do not overlook the B12 decline—monitor this trend as continued decline may require intervention 8

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Recommended Next Steps

1. Metabolic panel: Lipids, hemoglobin A1c, fasting insulin if not already done 2
2. Viral hepatitis screening: HBsAg, anti-HCV 2
3. Liver ultrasound: To assess for hepatic steatosis 2
4. Repeat ferritin and liver enzymes in 3-6 months after addressing modifiable factors (weight loss if overweight, alcohol cessation if applicable) 7, 2
5. Vitamin D and zinc supplementation [@patient data@]
6. Monitor B12 trend in 3-6 months 2