Nutrient depletion·Vitamin D·Reviewed June 9, 2026
What depletes vitamin d?
12 medications in the NutriStack database are documented to lower Vitamin D with ongoing use, most notably Carbamazepine, Phenobarbital, Phenytoin, and Primidone. The pattern spans 8 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 D depletion at a glance.
A quick, data-grounded summary. The per-medication table is below.
12 medications in the NutriStack database are documented to lower Vitamin D with ongoing use, most notably Carbamazepine, Phenobarbital, Phenytoin, and Primidone. The pattern spans 8 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 d.
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 d | Monitor |
|---|---|---|---|
| Carbamazepine Antiepileptic | Significant | Enzyme induction increases vitamin D breakdown, contributing to osteopenia with long-term use. | 25-OH vitamin D |
| Phenobarbital Barbiturate anticonvulsant | Significant | Phenobarbital induces hepatic enzymes that accelerate vitamin D catabolism, lowering 25-hydroxyvitamin D and reducing calcium absorption. | Serum 25-hydroxyvitamin D |
| Phenytoin Antiepileptic | Significant | Hepatic enzyme induction accelerates vitamin D catabolism, lowering active vitamin D availability and worsening bone loss. | 25-OH vitamin D |
| Primidone Anticonvulsant metabolized to phenobarbital | Significant | Primidone's phenobarbital metabolite and enzyme-inducing effects accelerate vitamin D catabolism. | Serum 25-hydroxyvitamin D |
| Cholestyramine Bile acid sequestrant | Moderate | Bile acid sequestration can impair absorption of fat-soluble vitamin D. | 25-hydroxyvitamin D |
| Dexamethasone Corticosteroid | Moderate | Glucocorticoids impair activation and signaling of vitamin D, reducing calcium absorption and bone support. | 25-OH vitamin D |
| Methylprednisolone Corticosteroid | Moderate | Glucocorticoids impair activation and signaling of vitamin D, reducing calcium absorption and bone support. | 25-OH vitamin D |
| Prednisolone Corticosteroid | Moderate | Glucocorticoids impair activation and signaling of vitamin D, reducing calcium absorption and bone support. | 25-OH vitamin D |
| Prednisone Corticosteroid | Moderate | Glucocorticoids impair activation and signaling of vitamin D, reducing calcium absorption and bone support. | 25-OH vitamin D |
| Rifampin Rifamycin Antibiotic | Moderate | Rifampin induces hepatic enzymes that accelerate vitamin D catabolism during prolonged therapy. | 25-hydroxyvitamin D |
| Valproic Acid Mood Stabilizer / Anticonvulsant | Moderate | Chronic valproate use is associated with lower vitamin D status and impaired bone health. | 25-OH vitamin D |
| Tenofovir Disoproxil Nucleotide reverse-transcriptase inhibitor (NRTI) | Mild | Proximal tubular injury reduces renal 1-alpha-hydroxylase activity and impairs conversion of 25-hydroxyvitamin D to active 1,25-dihydroxyvitamin D,... | Serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone (PTH) |
If you need to restore vitamin d.
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 d.
Common vitamin d depletion questions.
Quick answers drawn from the table above.
Which medications deplete vitamin d?
12 medications in the NutriStack database are documented to lower vitamin d, including Carbamazepine, Phenobarbital, Phenytoin, Primidone, and Cholestyramine. Severity differs by drug; the full table with mechanisms and monitoring biomarkers is on this page.
How do I know if my vitamin d is low?
The biomarkers used to track vitamin d status in this context include 25-OH vitamin D, Serum 25-hydroxyvitamin D, and 25-hydroxyvitamin D. 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 d 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.
Check your whole stack
See what your medications deplete.
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