Is Vitamin D Safe to Take With Lamictal?
In our latest question and answer, the pharmacist discusses whether or not it is safe to take Lamictal with Vitamin D.
Hello, I currently take 200mg of Lamictal in the mornings for bipolar disorder, as well as 300mg of Wellbutrin. I have been dx with a vitamin D deficiency in the past. I have been feeling extremely tired lately and I fear it may be that my vitamin D level has dropped again. I remember seeing something stating that vitamin D should not be taken with Lamictal, but today I looked it up again and am not seeing that same advice. Can you please tell me if I can take vitamin D with both of the medications I am taking, especially since my levels have been very low in the past? I cannot remember the units that vitamin D is measured in when looking at blood tests, but I remember my number was 12. This was in 2020. Thank you for any guidance!
Dec 12, 2022- Vitamin D and Lamictal are safe to take together with no known interaction between them.
- Some other antiepileptic drugs like phenytoin and carbamazepine can interfere with Vitamin D metabolism, but this does not appear to be a problem with Lamictal.
- Vitamin D levels are typically checked using a serum 25-hydroxy vitamin D test measured in ng/mL units, with normal levels generally ranging from 20-40 ng/mL.
Answer
Thanks for reaching out! There is no known interaction between Lamictal (lamotrigine) and Vitamin D. They are considered to be safe to be taken together.
I'm not sure where you would have read that Vitamin D interacts with Lamictal, but if you ever find your source for that information, I'd love for you to send it my way so I can take a look at it.
It may be possible that you saw some issues with Vitamin D and other antiepileptic drugs.
For example, phenytoin and carbamazepine, very commonly used antiepileptics, can decrease the activity of vitamin D by increasing its metabolism. Although rare, some studies have shown that individuals taking phenytoin for a long period of time may be more at risk for developing rickets, which is caused by a Vitamin D deficiency.
Due to some anti-epileptic drugs causing problems with Vitamin D, and thus bone density, they are oftentimes all grouped together in regard to this side effect. This, however, does not seem to be the case with Lamictal.
Wellbutrin (bupropion), the other drug you mention in your question, is also safe to take with Vitamin D.
How Vitamin D Blood Levels Are Checked
You mentioned wanting to know how Vitamin D levels are checked, specifically, what units are used in lab tests.
The most commonly used laboratory test for evaluating Vitamin D levels is the serum 25(OH)D [25-hydroxy vitamin D] concentration test. Now, what 'normal' levels are, and what units are used, varies. Nevertheless, the most common unit used is ng/mL (nanogram per ml). You may also see units reported as nmol/L (nanomoles per liter) in countries outside the United States.
Various sources and medical groups have different Vitamin D reference levels, but it generally ranges from 20-40 ng/mL. The 'Endocrine Society' gives the following reference ranges:
- Vitamin D deficiency: At or below 20 ng/ml
- Vitamin D insufficiency: 21-29 ng/ml
- Vitamin D sufficiency: 30-100 ng/ml
Other groups have different standards. For example, the International Osteoporosis Foundation recommends that a minimum level of 30 ng/mL is necessary in older adults to minimize the risk of fractures due to falls.
Final Words
I hope this answer was what you were looking for! Reach back out anytime!
References & sources
- Neuroprotective effects of vitamin D alone or in combination with lamotrigine against lithium-pilocarpine model of status epilepticus in rats — PubMed
- Influence of drugs on vitamin D and calcium metabolism — PubMed
- Vitamin D enhances antiepileptic and cognitive effects of lamotrigine in pentylenetetrazole-kindled rats — PubMed
- IOF position statement: vitamin D recommendations for older adults — PubMed
- Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline — PubMed
Glossary — Terms in This Answer
- Lamictal
- A brand name for the medication lamotrigine, which is used to treat seizures and certain mood disorders.
- Antiepileptic drugs
- Medications used to prevent or control seizures in people with epilepsy.
- Phenytoin
- An antiepileptic medication that can reduce vitamin D activity by speeding up how the body breaks it down.
- Carbamazepine
- An antiepileptic medication that can reduce vitamin D activity by speeding up how the body breaks it down.
- Rickets
- A bone disease in children caused by vitamin D deficiency that prevents bones from hardening properly.
- Serum 25(OH)D
- The main form of vitamin D found in the blood that doctors measure to check a person's vitamin D levels.
- Ng/mL
- Nanograms per milliliter, a unit of measurement used to report vitamin D levels in blood tests.
- Endocrine Society
- A professional medical organization that sets reference standards for hormone and vitamin levels in the body.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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