Is Vitamin D Safe with Carbamazepine?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Supplement with vitamin D3 (1000–2000 IU/day). Monitor serum 25-OH vitamin D, calcium, and alkaline phosphatase annually. Weight-bearing exercise and adequate dietary calcium are also recommended.
Why this interaction occurs
Carbamazepine strongly induces CYP3A4 and CYP2C9, increasing the hydroxylation and inactivation of vitamin D metabolites. This leads to reduced calcium absorption, osteomalacia, and significantly increased fracture risk in long-term users.
Evidence
Evidence level: strong.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 37,681 reports mentioning Carbamazepine. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Carbamazepine + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Vitamin D interactions → · All Carbamazepine interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.