Tea and Folic Acid: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Folic Acid
Tea
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Decreased folic acid exposure
Interaction Deep Dive
Concomitant use of folic acid and green or black tea resulted in decreased folic acid plasma levels. In healthy volunteers, concomitant administration of folic acid 0.4 mg with either green or black tea reduced the mean AUC of folic acid by 26.6% and 17.9%, respectively, as well as Cmax of serum folate by 39.2% and 38.6%, respectively; and folic acid 5 mg coadministered with green tea reduced the mean AUC of folic acid by 39.9% and the mean Cmax of serum folate by 27.4%1. Avoid using folic acid and green or black tea together, especially in pregnant women.
Why it happens (mechanism)
Decreased folate absorption
Literature reports
1 report — tap to read
a) An open-label, randomized crossover study of patients receiving folic acid in combination with either black or green tea showed a reduction in folic acid AUC and Cmax. Seven healthy volunteers received 5 different treatments consisting of folic acid (0.4 mg/day or 5 mg/day) in combination with either green or black tea (0.3 g/250 mL) or water, as a reference drink. A wash-out period of at least 1 week was maintained between treatments. To minimize individual differences in baseline folate plasma serum concentrations, a regimen with folic acid 5 mg/day for 1 week followed by 2 folic acid-free days along with study drinks 3 times daily (tea concentration, 0.3 g/250mL) were administered prior to and in between treatment periods. Plasma samples were collected over 8 hours. Coadministration of folic acid 0.4 mg with either green or black tea reduced the mean AUC of folic acid by 26.6% and 17.9%, respectively, as well as Cmax of serum folate by 39.2% and 38.6%, respectively. Relative bioavailability of folic acid was 77.7% with green tea and 88.4% with black tea. Coadministration of folic acid 5 mg with green tea reduced the mean AUC of folic acid by 39.9% and the mean Cmax of serum folate by 27.4%. Relative bioavailability of folic acid was 60% with green tea 1.
Common questions
Can I take Tea and Folic Acid together?
Decreased folic acid exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Tea and Folic Acid interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Tea or Folic Acid need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Alemdaroglu NC, Dietz U, Wolffram S, et al: Influence of green and black tea on folic acid pharmacokinetics in healthy volunteers: potential risk of diminished folic acid bioavailability. Biopharm Drug Dispos 2008; 29(6):335-348. PubMed
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