Anticonvulsants
Common brand names: Phenytoin (Dilantin), Carbamazepine, Phenobarbital
Three nutrients listed against this medication. The most severe is marked critical.
At a glance
All three are marked well documented.
At a glance
- Folate (Methylfolate)Critical · Well documented
- Vitamin D3Critical · Well documented
- Biotin (Vitamin B7)Moderate · Well documented
Color shows how serious each listed effect is. The label beside it shows how strong the evidence is. The cards below explain each one and show its evidence.
Nutrients it can lower
Mechanism, Several anticonvulsants (phenytoin, carbamazepine, valproate) are folate antagonists or accelerate folate metabolism via CYP450 induction. Folate deficiency is one of the best-documented drug-nutrient interactions.
Common signs, Megaloblastic anemia, elevated homocysteine An amino acid in the blood that rises when vitamin B12, folate or B6 are low., cognitive decline, birth defects if pregnant
Kathiravan et al. (Sci Rep, 2021; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 33623072): long-term antiepileptic therapy significantly lowered serum folate and vitamin B12 in epileptic patients.
L-methylfolate was used at 800 mcg–5 mg daily, with higher doses in phenytoin users. Folic acid is avoided here, as it may reduce anticonvulsant efficacy in some patients; this is discussed with the neurologist.
Mechanism, Enzyme-inducing anticonvulsants (phenytoin, carbamazepine, phenobarbital) accelerate Vitamin D catabolism via CYP3A4 induction. Deficiency develops faster than with most other drugs.
Common signs, Bone loss, fractures, osteomalacia, muscle weakness, immune impairment
Valsamis et al. (Nutr Metab, 2006; PMID 16956398): review of antiepileptic drugs and bone metabolism: enzyme-inducing agents are associated with lower vitamin D and reduced bone density.
Vitamin D3 was used at 2,000 to 4,000 IU daily in the cited literature, with 25(OH)D monitored. The cited review sets no concentration target and EBL publishes none.
Mechanism, Anticonvulsants impair biotin metabolism. Valproate specifically interferes with biotin utilization and biotinidase activity.
Common signs, Hair loss, skin rash, fatigue, cognitive changes
Krause et al. (Ann N Y Acad Sci, 1985; PMID 3925859): plasma biotin was markedly lower in 404 epileptics on long-term anticonvulsants than in controls.
Biotin 1,000–5,000 mcg daily is a range in common use, not from a trial cited on this row. The cited paper measured biotin status in people with epilepsy and tested no repletion dose.
For your next appointment
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Disclosure
These statements have not been evaluated by the Food and Drug Administration. Any grade on this page describes the strength of published human trial evidence in the populations studied. It is not a recommendation for any individual and is not medical advice. Starting, stopping or changing any supplement or medication is a decision for your physician.
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