What should I do about my elevated vitamin B-12 (B-12) level and low protein level, considering I'm currently taking a B-12 supplement?

Management of Elevated B-12 and Low Protein Levels

B-12 Supplementation: Stop Your Supplement Immediately

You should discontinue your B-12 supplement and undergo evaluation for underlying conditions that cause elevated B-12 levels, as high B-12 is not a sign of excess supplementation but rather a potential marker of serious disease. 1

Why Elevated B-12 Requires Investigation

• Elevated vitamin B12 levels (>350 ng/L or >258 pmol/L) are not caused by over-supplementation in the way you might think—they signal potential underlying pathology that requires workup 1
• High B-12 has been linked to increased mortality and cancer risk, with risk ratios ranging from 1.88 to 5.9 1
• Common causes include hematologic disorders (myeloproliferative neoplasms, leukemia), liver disease (hepatocellular carcinoma), and kidney disease 1, 2

Required Diagnostic Workup

Initial testing should include: 1

• Complete blood count with differential to assess for blood cancers
• Comprehensive metabolic panel with liver function tests
• Serum tryptase measurement (often elevated alongside B-12 in myeloproliferative disorders)

If initial workup is negative but B-12 remains elevated: 1

• Periodic monitoring with CBC and liver function tests every 3-6 months
• Consider hematology referral if levels remain persistently elevated or if any blood count abnormalities develop

Important Caveat About "Functional Deficiency"

• Even with elevated total B-12, you could theoretically have functional B-12 deficiency if the biologically active form is low 1
• However, this is uncommon when total B-12 is truly elevated, and the priority is ruling out serious disease first 3

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Low Protein: Address This Through Diet and Medical Evaluation

Your low protein level requires both dietary intervention and medical evaluation to identify any underlying malabsorption or loss conditions.

Immediate Dietary Approach

Target protein intake: 3

• Aim for 1.2-1.6 g/kg body weight daily (higher than standard 0.8 g/kg for healthy adults)
• Distribute protein across all meals (20-30g per meal) rather than loading one meal
• Include both animal sources (meat, fish, eggs, dairy) and plant sources (legumes, nuts, soy)

Medical Evaluation Needed

Your doctor should assess for: 3, 4

• Malabsorption conditions: Celiac disease, inflammatory bowel disease, pancreatic insufficiency
• Protein-losing conditions: Kidney disease (proteinuria), protein-losing enteropathy
• Inadequate intake: Restrictive diets, eating disorders, dental problems affecting chewing
• Medications: Certain drugs can affect protein metabolism or absorption

Connection to B-12 Issues

• If you have malabsorption causing low protein, this could also affect B-12 absorption (though your B-12 is elevated, suggesting a different mechanism) 3
• Conditions like Crohn's disease or celiac disease can cause both protein malabsorption and B-12 deficiency 3, 5

Monitoring Strategy

Follow-up testing should occur: 5

• Recheck protein levels (albumin, total protein, prealbumin) in 3 months after dietary intervention
• If levels don't improve, pursue gastroenterology referral for malabsorption workup
• Consider checking other nutritional markers: iron, folate, vitamin D, zinc

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Critical Action Items

1. Stop B-12 supplement immediately and get the diagnostic workup for elevated B-12 1
2. Increase dietary protein intake to 1.2-1.6 g/kg/day distributed across meals 3
3. Schedule follow-up with your physician for comprehensive evaluation of both issues
4. Do not ignore the elevated B-12—this is the more urgent concern requiring medical investigation 1