ICD-10-CM Codes for Ordering Vitamin B6 (Pyridoxine) Level
Use ICD-10 code E53.1 (Pyridoxine deficiency) as your primary code when ordering a vitamin B6 level for suspected deficiency, or code E56.9 (Deficiency of other vitamins, unspecified) as a broader alternative when B6 deficiency is part of a differential diagnosis.
Primary Diagnostic Codes
Direct Vitamin B6-Related Codes
- E53.1 – Pyridoxine deficiency: This is the most specific code for suspected vitamin B6 deficiency and should be your first choice when clinical suspicion exists 1, 2
- E56.9 – Deficiency of other vitamins, unspecified: Use this when B6 deficiency is suspected but not yet confirmed, or when evaluating multiple vitamin deficiencies simultaneously 1
Clinical Scenarios That Support B6 Testing
Neurological Presentations
- G62.9 – Polyneuropathy, unspecified: Appropriate when evaluating peripheral neuropathy of unclear etiology, since both B6 deficiency and toxicity can cause sensory neuropathy 3, 4
- G63 – Polyneuropathy in diseases classified elsewhere: Use when neuropathy is secondary to a known condition that may affect B6 status 3
- R20.2 – Paresthesia of skin: Justified when patients present with numbness or tingling that could represent either B6 deficiency or toxicity 1, 4
Hematologic Indications
- D64.9 – Anemia, unspecified: B6 deficiency can cause microcytic anemia, making this code appropriate when evaluating unexplained anemia 1, 5
- D64.89 – Other specified anemias: More specific code when microcytic anemia is present and B6 deficiency is in the differential 1
Renal Disease Context
- N18.3 through N18.6 – Chronic kidney disease, stage 3-5: Patients with CKD are at high risk for B6 deficiency and require monitoring, particularly those on dialysis 1, 6
- Z99.2 – Dependence on renal dialysis: Hemodialysis patients have documented B6 deficiency and require supplementation monitoring 6
Medication-Related Monitoring
- Z79.2 – Long-term (current) use of antibiotics: Appropriate when monitoring patients on isoniazid therapy who require B6 supplementation 7, 8
- T37.1X5A – Adverse effect of antimycobacterial drugs, initial encounter: Use when evaluating for isoniazid-induced neuropathy where B6 status is relevant 7
Pregnancy-Related Testing
- O21.9 – Vomiting of pregnancy, unspecified: Justified when evaluating B6 status in pregnant patients with nausea/vomiting, especially if considering or monitoring pyridoxine therapy 7
- Z34.90 – Encounter for supervision of normal pregnancy, unspecified: Can support B6 testing in pregnancy when supplementation is being considered 7
Toxicity Evaluation
- T45.2X5A – Adverse effect of vitamins, initial encounter: Use this code when evaluating suspected vitamin B6 toxicity from excessive supplementation 3, 9
- G62.2 – Polyneuropathy due to other toxic agents: Appropriate when neuropathy is suspected to be caused by excessive B6 intake 3, 4
Important Clinical Context for Ordering
High-Risk Populations Requiring Monitoring
- Chronic kidney disease patients (especially on dialysis) have markedly reduced B6 clearance and are at risk for both deficiency and toxicity 3, 6
- Patients on isoniazid therapy require B6 supplementation and periodic monitoring 7, 8
- Elderly patients with poor nutritional intake may have inadequate B6 status despite normal dietary intake 5
- Patients with alcohol use disorder are at risk for functional B6 deficiency even with supplementation 3
Critical Pitfall to Avoid
- When ordering B6 levels in patients with inflammatory conditions or low albumin, specify measurement of pyridoxal-5'-phosphate (PLP) in red blood cells rather than plasma, as plasma levels may be falsely low 3
- Document the specific clinical indication clearly in your order, as plasma PLP >30 nmol/L (7.4 μg/L) indicates adequate status, while levels >100 nmol/L (25 μg/L) suggest potential toxicity risk 5