Nutrient depletion·Vitamin B6·Reviewed June 9, 2026
What depletes vitamin b6?
6 medications in the NutriStack database are documented to lower Vitamin B6 with ongoing use, most notably Isoniazid. The pattern spans 6 drug classes. Depletion builds slowly and is easy to miss; the table below shows how each medication drives it and which biomarker to check. Never start a replacement supplement without your prescriber's input.
Vitamin B6 depletion at a glance.
A quick, data-grounded summary. The per-medication table is below.
6 medications in the NutriStack database are documented to lower Vitamin B6 with ongoing use, most notably Isoniazid. The pattern spans 6 drug classes. Depletion builds slowly and is easy to miss; the table below shows how each medication drives it and which biomarker to check. Never start a replacement supplement without your prescriber's input.
What is documented to lower vitamin b6.
Worst documented severity first. Open any medication for its full interaction and depletion guide. Absence from this table means no documented record, not proven safety.
| Medication | Severity | How it lowers vitamin b6 | Monitor |
|---|---|---|---|
| Isoniazid Antitubercular antibiotic | Significant | Isoniazid antagonizes pyridoxine metabolism and increases risk of pyridoxine-responsive peripheral neuropathy. | Clinical neuropathy assessment; pyridoxal 5-phosphate if available |
| Combined Oral Contraceptive Hormonal Contraceptive | Moderate | Estrogen-containing contraceptives can increase vitamin B6 turnover and lower circulating PLP in susceptible users. | Plasma PLP |
| Hydralazine Direct Arteriolar Vasodilator | Moderate | Hydralazine can antagonize pyridoxine metabolism and has been linked to pyridoxine-deficiency neuropathy during prolonged therapy. | Clinical neuropathy assessment + plasma PLP if available |
| Levodopa/Carbidopa Dopaminergic / Antiparkinson | Moderate | Carbidopa can bind pyridoxal phosphate and reduce functional vitamin B6 availability during chronic levodopa-carbidopa therapy. | Plasma PLP + neurologic symptoms |
| Phenelzine Irreversible nonselective monoamine oxidase inhibitor antidepressant | Moderate | Phenelzine is a hydrazine derivative that can bind or inactivate pyridoxal-5-phosphate, reducing active vitamin B6 availability and impairing... | Plasma pyridoxal-5-phosphate and clinical monitoring for paresthesias or neuropathy |
| Theophylline Methylxanthine bronchodilator | Moderate | Theophylline exposure has been associated with reduced pyridoxal phosphate status and may increase neurologic vulnerability in susceptible patients. | Plasma pyridoxal-5-phosphate when clinically indicated |
If you need to restore vitamin b6.
Repletion is not automatic: dose, form, and timing depend on the medication involved, and some pairings need separation from the very drug causing the depletion. Confirm with your prescriber before adding vitamin b6.
Common vitamin b6 depletion questions.
Quick answers drawn from the table above.
Which medications deplete vitamin b6?
6 medications in the NutriStack database are documented to lower vitamin b6, including Isoniazid, Combined Oral Contraceptive, Hydralazine, Levodopa/Carbidopa, and Phenelzine. Severity differs by drug; the full table with mechanisms and monitoring biomarkers is on this page.
How do I know if my vitamin b6 is low?
The biomarkers used to track vitamin b6 status in this context include Clinical neuropathy assessment; pyridoxal 5-phosphate if available, Plasma PLP, and Clinical neuropathy assessment + plasma PLP if available. If you take one of the medications above long term, ask your prescriber whether checking is worthwhile; depletion develops gradually.
Should I take a vitamin b6 supplement with these medications?
Not automatically. Documented depletion makes repletion worth discussing, but the right answer depends on your labs, dose, and the specific drug. Bring it up with your prescriber or pharmacist.
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See what your medications deplete.
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