What happens when you take green tea with folate?
Green tea contains polyphenols called catechins, the most abundant of which is epigallocatechin-3-gallate (EGCG). When green tea and a folate supplement are in the gut at the same time, the catechins get in the way of how folate is absorbed and used. Here is the sequence:
- Transporter competition. EGCG partly blocks the proton-coupled folate transporter (PCFT) in the upper small intestine. This is the main carrier that ferries both dietary folate and synthetic folic acid across the gut wall into the blood.
- Slower conversion to the active form. EGCG can also interfere with dihydrofolate reductase (DHFR), an enzyme that helps convert synthetic folic acid into the active forms of the vitamin that your cells actually use.
- Some oxidative breakdown. In solution, EGCG can generate small amounts of hydrogen peroxide that degrade active folate. Vitamin C appears to counter this effect.
- The net result. In a controlled human study, taking folic acid with green tea modestly lowered both the peak blood level and the total amount absorbed compared with taking it with plain water. The effect is real but small, and it depends on the two being taken together.
Why is this important?
Folate (vitamin B9) is essential for making DNA, forming red blood cells, and supporting healthy neural tube development in early pregnancy. Adequate folate around conception and in the first trimester lowers the risk of neural tube defects such as spina bifida. For this reason, women who could become pregnant are advised to take folic acid daily.
Because folate status at this stage matters so much, it makes sense not to give away even a modest amount of absorption needlessly. If a prenatal vitamin is routinely washed down with a cup of green tea, a small slice of the folic acid is absorbed less efficiently than it would be with water. A single occasion is not a concern, but over weeks of daily supplementation it is worth taking the easy step of separating them.
The interaction is gentle for most people and is not a reason to avoid green tea, which is otherwise a healthy beverage. The groups who should pay a little more attention are women planning a pregnancy or in early pregnancy, people taking folic acid to correct a deficiency, and anyone using concentrated green tea extract supplements, where catechin amounts are far higher than in a brewed cup.
What should you do?
The whole interaction comes down to timing, and it is simple to manage. Use the following routine:
- Before you change anything: if you are pregnant, planning a pregnancy, or taking folic acid for a diagnosed deficiency, mention your green tea habit to your doctor or pharmacist so any advice fits your situation.
- Every day: take your folic acid or prenatal supplement with plain water, ideally earlier in the day. Pairing it with a vitamin C source such as a glass of orange juice is a reasonable extra step. Then enjoy green tea later, a few hours apart from the supplement.
- If you use green tea extract capsules: keep these well separated in time from your folate dose, since the catechin load is much higher than in a brewed cup.
- After you change your routine: no monitoring is needed for a healthy adult. If you are being treated for a deficiency, follow up with your clinician as they advise.
Choosing the active form of the vitamin (methylfolate, or 5-MTHF) sidesteps the conversion-enzyme step, but it still uses the same intestinal transporter as folic acid, so the timing principle still applies.
Which specific products are affected?
On the folate side, the interaction applies to synthetic folic acid in prenatal vitamins, standalone folic acid tablets, B-complex supplements, and folic-acid-fortified foods such as enriched cereals, bread, and pasta. It also applies to active L-methylfolate (5-MTHF) supplements, because both forms share the same intestinal transporter. Dietary folate from leafy greens, legumes, and citrus uses the same pathway, though the everyday amounts involved make any effect hard to notice.
On the green tea side, all forms contain catechins: brewed green teas (sencha, matcha, gyokuro, jasmine green), bottled green tea drinks, and most of all concentrated green tea extract supplements. Decaffeinated green tea still contains catechins and behaves the same way. Black tea has been reported to produce a similar but smaller reduction.
The science behind it
The clearest human evidence comes from a randomized crossover study in healthy volunteers (Alemdaroglu and colleagues, 2008). Taking folic acid together with green tea lowered both the peak blood concentration and the total absorption of the folic acid compared with taking it with water. Importantly, the size of the reduction in that study was modest, not the dramatic loss sometimes claimed elsewhere, and it reflects the two being consumed at the same time.
The mechanism behind that observation has been examined in laboratory work. A transporter study (Narawa and colleagues, 2025) showed that green tea and EGCG directly reduce folic acid transport by the proton-coupled folate transporter, which explains why absorption falls when the two are taken together. Taken together, the human and laboratory evidence agree on the direction of the effect while indicating that its everyday magnitude is small.
Frequently Asked Questions
Do I have to give up green tea if I take a folate supplement?
No. Green tea is a healthy drink, and the interaction is modest. You only need to avoid taking it at the same moment as your folate; drinking it a few hours apart removes the issue.
How long should I wait between my folate supplement and green tea?
There is no precise required gap. Taking the supplement with water and having green tea a few hours later is more than enough separation in practice.
Does this matter if I am not pregnant?
For most healthy adults the effect is minor and not a practical concern. It is most worth attention for people planning or in early pregnancy and for anyone being treated for folate deficiency.
Will switching to methylfolate solve it?
Methylfolate avoids the conversion-enzyme step, but it still uses the same intestinal transporter as folic acid, so separating it from green tea in time is still the sensible approach.
Are green tea extract capsules worse than brewed tea?
They can have a stronger effect because they concentrate the catechins well beyond what a cup of tea provides. Keep extract supplements well separated from your folate dose.
Does vitamin C help?
Vitamin C appears to protect folate from the oxidative breakdown caused by EGCG, so taking folate with a vitamin C source such as orange juice is a reasonable extra step.
Key takeaways
- Green tea catechins modestly reduce folic acid absorption when the two are taken together; the effect is small and easily avoided.
- Take folate or prenatal supplements with water, and enjoy green tea a few hours apart.
- This matters most around pregnancy planning, early pregnancy, and treatment of folate deficiency; discuss your routine with your doctor or pharmacist.
- Concentrated green tea extract capsules have a stronger effect than brewed tea, so keep them well separated from folate.
- Methylfolate still shares the same intestinal transporter, so the timing principle applies to it too.