Can You Drink Coffee With an Iron Supplement?

Why it happens

Coffee polyphenols can reduce nonheme iron absorption. In a study of women with iron deficiency, absorption was much lower when iron was taken with coffee or breakfast than when it was taken with orange juice alone.

What to do

Do not use coffee to take an iron supplement. Unless your product instructions, doctor, or pharmacist says otherwise, leave 1–2 hours between them.

What the evidence actually showed

The key study looked at women with iron deficiency and found that absorption was much lower when iron was taken with coffee or breakfast than when it was taken with orange juice alone. This comparison is useful because it shows the effect in the population most likely to be paying attention to iron absorption in the first place — people already low in iron — rather than in people with normal iron stores where the practical stakes are lower. The mechanism behind it is that coffee polyphenols reduce nonheme iron absorption, similar to the effect seen with tea.

How to actually schedule it

The simplest approach is to avoid using coffee as the drink you take your iron supplement with, and to build in a 1–2 hour gap between the two unless your product instructions, doctor, or pharmacist gives you a different window. Because the size of the effect can vary with the meal, the type and dose of iron, and your own iron stores, this range is meant as general guidance rather than an exact cutoff. If you have a prescribed iron product, its specific instructions take priority over this general range.

References

• Effect of dietary factors and time of day on iron absorption from oral iron supplements in iron deficient womeneClinicalMedicine / PubMed · 2023
• AnaemiaWorld Health Organization · 2025

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