Iron Inhibitors: Foods That Reduce Your Iron Absorption

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Follow Me on Pinterest Iron is an interesting mineral because other foods can enhance or inhibit our iron absorption. It is not enough to look at the iron content of food on a label, we need to look at our whole meal to get a sense of how iron-rich the meal is.

That said, there is some confusion about iron inhibitors — how much iron they inhibit, how bad these foods are for us to eat. The best way to think about inhibitors is to divide them into two groups: (1) Foods that contain inhibitors with little iron themselves and (2) foods with inhibitors that are also loaded with iron (iron that happens to be “locked up” in the food by the inhibitors).

Low Iron Foods With Iron Inhibitors

This category of food contains primarily beverages: milk, coffee, black tea, and red wine. These beverages typically offer minimal iron but will actually inhibit your absorption of iron in foods you eat in the same meal. Breakfast cereal is a great example: many cereal manufacturers pack your processed breakfast cereal with fortified iron because the milk you pour over it will inhibit some of that iron.

For this group of inhibitors, it is best to avoid consuming them with your iron-rich meal. I realize you are not going to give up your coffee, but you can plan an iron-rich dinner well after your early afternoon cup of coffee. You may also rely on milk for calcium like I do. If you are like me, drink the milk a couple of hours before or after your iron-rich meal. I give my son warm milk at night as a sleep aid and a calcium boost rolled into one.

High Iron Foods With Iron Inhibitors

In this category, we have high iron classics: spinach, soybeans, and corn. The iron in vegetables is blocked primarily by oxalic acid. Phytic acid is the culprit in grains, legumes, nut, and seeds. These foods tend to have enough iron that even with these iron blockers, you will still get iron out of them. They are also not so sinister that they will rob iron out of your body. I would not be afraid to eat these foods, I would just take care to prepare them to reduce their iron inhibitors. How you prepare each of these foods depends on the inhibitor.

Preparing Grains, Legumes, Nuts, and Seeds to Reduce Phytic Acid

The best way to reduce phytic acid in food comes down to one word: soak and ferment. If you place the food in warm water for hours (or even for a day), the content of phytic acid will decrease or may disappear entirely. There are some exceptions for which it is difficult to remove the phytic acid (notably, soy and corn which I will leave to other discussions). For much of the rest of the food world, you can improve the phytic acid reduction by soaking a ground version of the food (cracked or ground grains, chopped nuts). You can also improve your iron absorption by eating these foods with high vitamin C foods such as tomatoes, peppers, and oranges. There are more tricks to improving your iron absorption from high phytic acid food that I will add to this website. The tricks and exceptions are described in detail in my digital books on iron rich foods and phytic acid.

Vegetables High in Oxalic Acid

For vegetables high in oxalic acid, your best strategy is to boil them and discard the boiling water. (I describe the research in more detail here as it relates to calcium but it applies to iron as well.) Eating foods high in vitamin C along with your vegetables may help as well, especially if you are boiling all of the vitamin C out of your spinach. :)

I get some flack from spinach lovers over this point and the fact is that I am a big fan of raw spinach salads but if you need the spinach for iron, your best strategy is to boil it and eat it mushy. (I know.)

Avoid Iron Inhibitors?

In general, I do not avoid foods just because they contain iron inhibitors. I am enjoying a cup of black tea as I write. However, at the times in my life when I have found myself iron deficient, I do take more care in planning my meals and avoiding iron-inhibiting foods if I cannot prepare them to reduce their phytic acid and oxalic acid. On a daily basis, I prepare much of my high phytic acid food to reduce the phytic acid. The strategies are fairly simple and, ultimately, they reduce my cooking time. It is less of a kitchen obsession than it is a regular routine.

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16 Responses to Iron Inhibitors: Foods That Reduce Your Iron Absorption
  1. Thea Harvey
    May 31, 2012 | 10:22 am

    You do not explain what it is in milk that inhibits iron absorption. I wonder if there is any difference in raw and processed milk in this regard.

  2. Amanda Rose
    May 31, 2012 | 2:41 pm

    Hi Thea. Good question. It’s actually the calcium so I wouldn’t expect to see a difference.

  3. Kathy (aka Mrs Dull)
    June 5, 2012 | 5:45 am

    Great post! I’d like to invite you to share with us at Scratch Cookin’ Tuesday.

  4. mjskit
    June 6, 2012 | 12:23 am

    Very interesting article! I have chronic illness anemia so I have to take iron supplements. I try to take them with vitamin C, but I didn’t know there were so many iron inhibitors in our foods. Thanks for this information!

  5. Debra
    June 6, 2012 | 8:33 am

    I love this post, lots of great information, but does green tea have the same effect as black tea? It must since it’s the same plant. I have been drinking lots of it lately and have wondered if it has any negative effects.

  6. Amanda Rose
    June 6, 2012 | 4:16 pm

    Debra — Good question. I’ll look for a study that compares them.

  7. marilyn
    June 7, 2012 | 3:48 am

    Thanks. I needed a refresher course on this. I have been trying to get my anemia controlled for years. I have Crohns. At one time I took inferon injections but the dr. don’t want to carry it for some reason. I took trinsicon for a while but my new dr. seems to think otc iron with C will do the trick. It has been over a year and my iron count has come up a bit. I think I will do more research on this subject. So thanks for the post, it has given me more options to explore.

  8. Becca
    June 7, 2012 | 1:39 pm

    Great information! I didn’t realize that the way you prepare spinach affects the oxalic acid.

    Because calcium inhibits iron absorption, if you take supplements it’s important not to take these two at the same time. I take my calcium with coffee and my iron at bedtime.

  9. Lisa
    June 8, 2012 | 7:49 am

    Thanks for the great info and linking to Tempt My Tummy Tuesday.

  10. Anne
    June 9, 2012 | 6:24 am

    I struggled with anemia throughout my last pregnancy and really couldn’t make sense of what foods I should and shouldn’t eat with the iron-rich foods and my iron supplements. This is very informative – Thanks for linking up to Healthy 2Day Wednesday and come back next week to see if you were featured!

  11. Alea
    June 11, 2012 | 7:06 pm

    Great information! I have had low iron in the past and I never realized that I could be combining items that would actually inhibit my iron absorption. Fortunately, my iron levels are fine now.

  12. Petra
    June 12, 2012 | 2:56 am

    Hi, my husband has Gilberts syndrome (high iron levels in the blood). Would you have any suggestions on best foods to reduce his iron levels? Thanks.

  13. Amanda Rose
    June 13, 2012 | 8:11 pm

    I’m not a doctor and don’t know about Gilbert’s syndrome but in terms of food, I would just reverse the information on this site. High phytic acid food (grains, beans) may be very good for him. On lifestyle and depending on his condition, find out from your doctor if donating blood is an option.

  14. Sharron
    June 14, 2012 | 10:28 am

    Do you know anything about vitamin supplements which have both Iron, Vitamin C and Calcium?

  15. Amanda Rose
    June 17, 2012 | 2:23 pm


    Is it that you want all of those in a supplement? If you’re iron deficient, you can definitely find iron with vitamin C or complementary herbs, but it would be best to take the calcium separately at another time of day.


  16. Carrie
    July 1, 2012 | 10:40 am

    Thank you so much for this information. I just found out that I absorb too much iron, hemochromatosis, and need to find foods that have inhibitors.

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