Is Vitamin B12 (Methylcobalamin) Safe with Citalopram?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Test serum B12 and homocysteine levels at baseline and annually with long-term citalopram use. Supplement with methylcobalamin 1000 mcg daily if B12 is below 400 pg/mL or homocysteine is elevated.
Why this interaction occurs
Long-term SSRI therapy including citalopram may reduce B12 bioavailability through effects on gastric acid secretion and intrinsic factor activity, particularly in older adults. Elevated homocysteine secondary to B12 deficiency is associated with worsened depression and cardiovascular risk. Adequate B12 is necessary for the methylation cycle that supports neurotransmitter production.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 113,877 reports mentioning Citalopram. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Citalopram + 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 B12 (Methylcobalamin) interactions → · All Citalopram interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.