Is Vitamin D3 Safe with Fluoxetine?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Monitor 25-OH vitamin D levels annually during long-term fluoxetine therapy. Supplement with vitamin D3 (1000–2000 IU daily) if deficient. Adequate vitamin D may support antidepressant treatment outcomes.
Why this interaction occurs
Vitamin D receptors are present throughout the brain and modulate serotonergic neurotransmission. Low vitamin D levels are highly prevalent in depressed patients and may reduce SSRI effectiveness. While fluoxetine does not directly deplete vitamin D, patients on SSRIs for depression are at high risk of baseline deficiency that can undermine treatment response.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 87,365 reports mentioning Fluoxetine. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Fluoxetine + 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 D3 interactions → · All Fluoxetine interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.