Health Reference LibraryShould you take iron with coffee or tea?
This entry is part of the Nutri Tailor Health Reference Library — cited research on supplements, nutrients and adjacent areas of health.
Summary
Keep tea and coffee at least an hour clear of iron, and it is the hour after that matters. In the classic isotope studies, a cup of tea with a meal cut non haem iron absorption by 64 percent and coffee by 39 percent, and strong black tea with a bread meal by 79 to 94 percent. Coffee an hour before the meal caused no reduction; coffee an hour after inhibited as much as drinking it with the food. The 2017 UK trial softened the after side: a one hour gap after the meal roughly halved tea’s effect, from about 37 percent down to 18 percent. Milk in the tea changes little; the tannins are the problem.
Free iron and ferritin result interpreter
Enter what you have. Your ferritin alone works; the other fields sharpen the reading. Nothing you enter leaves this device. Nothing is saved. No AI is used, only published UK guideline thresholds.
This tool gives educational interpretation of published evidence. It is not personal dosing advice and it does not diagnose. It knows nothing about your history, symptoms or other results. Interpreting your results over time, alongside everything else about you, is what Nutri365 does.
How it works
The inhibitors are polyphenols, the tannin family in tea and the chlorogenic acids in coffee. They bind non haem iron in the gut into complexes the body cannot take up. The effect scales with strength: doubling the concentration of instant coffee in the classic study dropped fractional absorption from an already reduced level to under 1 percent. Haem iron from meat is largely unaffected, so this matters most for plant iron and for supplements, which are non haem.
Effective dose
The numbers to remember: tea with a meal, 64 percent less iron absorbed; coffee, 39 percent less; black tea with bread, 79 to 94 percent less; cocoa 71 percent; common herb teas 47 to 84 percent. In the UK trial, absorption from a porridge meal was 5.7 percent with water, 3.6 percent with tea alongside, and back to 5.7 percent when the tea came an hour later.
Timing
The rule has a direction. Coffee before is fine; coffee with or soon after is not. Have your tea or coffee, wait an hour, then take iron; or take iron and hold off the next cup for an hour, two if you can. For someone correcting a deficiency, first thing with water and coffee an hour later is the cleanest schedule.
Safety profile
Do not take iron for tiredness without a blood test. Keep iron out of reach of children. The polyphenol effect is a reason to time your drinks, not to give them up.
Interactions
Calcium is the other big inhibitor and needs a two hour gap. Vitamin C at the same meal increases absorption, which is why iron and vitamin C are sold together. Zinc competes only at high supplement doses on an empty stomach.
Guideline positions
Inhibition of food iron absorption by coffee (1983). Inhibition of non haem iron absorption by polyphenol containing beverages (1999). A one hour time interval between a meal containing iron and tea consumption attenuates the inhibitory effect, UK stable isotope trial (2017).
Practical framework
Move the drink, not the supplement. Nutri Tailor stocks iron bisglycinate with vitamin C, 15 mg of iron as bisglycinate with 400 mg of vitamin C per capsule, which is gentle enough to take mid morning between drinks, made in the UK. If you are correcting a low ferritin, retest after eight weeks. To read your own result against the UK ranges, use the free blood test result interpreter. This is a summary of published research, not personal health advice. Talk to your GP or a registered nutritional therapist before changing what you take, especially if you are pregnant, have a diagnosed condition or are under ongoing care.
Common misconceptions
That decaf is fine: the polyphenols are still there. That milk protects the iron: the trial found little difference. That herbal tea is safe with iron: peppermint and camomile inhibited absorption by around half. That the gap has to be before the coffee: the hour after is the one that counts.
Sources
- Morck TA, Lynch SR, Cook JD 1983. Inhibition of food iron absorption by coffee. American Journal of Clinical Nutrition 37(3):416-420, DOI 10.1093/ajcn/37.3.416, PMID 6402915.
- Hurrell RF, Reddy M, Cook JD 1999. Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. British Journal of Nutrition 81(4):289-295, PMID 10999016.
- Controlled stable-isotope trial investigators (UK cohort study) 2017. A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope. American Journal of Clinical Nutrition 106(6):1413-1421, DOI 10.3945/ajcn.117.161364, PMID 29046302.