How to increase iron absorption on a plant-based diet

foods that inhibit iron absorptionThere are several ways to ensure adequate iron intake but in addition to consuming iron-rich foods, there are certain foods you should avoid for maximum success.

Ways to ensure adequate iron intake:

  • Eat plenty of iron containing foods.

    These include dark leafy greens, beans, quinoa, oats, or soaked almonds or pumpkin seeds.

  • Enhance iron absorption by employing the “iron and acid” combination. Acids can increase absorption by as much as 40-60%!

    Acids include:

    1. Your own stomach acid.
    2. Ascorbic acid (vitamin C). Squeeze lemon juice over greens, or add vitamin C foods like bell peppers, cucumbers, or celery to your iron-rich salads or meals.
    3. Lactic acid. Include sour kraut or fermented veggies when iron-rich greens or legumes are served.
    4. Acetic acid (vinegar). Use vinegars on salads, greens, etc.

    NOTE: The acid-containing foods should be eaten at the same time as the iron-containing foods. Also,

  • Reduce inhibitors of absorption.

    The most common inhibitors are phytates (a carbohydrate in whole grains and legumes,) calcium in dairy products, and polyphenols such as tannic acid in tea, coffee, etc.

    To reduce phytate inhibition of iron absorption:

    Soaking, sprouting, leavening and fermenting whole grains break down phytates and thus will increase iron absorption

    Acidic substances specifically reduce phytates, so adding citrus (lemon juice, orange slices, etc. for vitamin C,) vinegar, and other acids to meals with legumes and whole grains significantly decreases inhibition of iron absorption.

To reduce polyphenol inhibition of iron absorption (tannins and flavonoids in tea, coffee, cocoa, red wine) – avoid consuming these beverages with iron-containing foods.

To reduce calcium inhibition of iron absorption

The effect of soy products on iron absorption is controversial. Some studies report an inhibitory effect, others do not. However, it is agreed that fermented soy products like tempeh and miso increase iron absorption.

Despite common beliefs, it appears that leafy greens and other foods containing oxalic acid do not seem to significantly inhibit iron absorption.  If oxalates are a factor, their effects will be minimized by cooking and/or by serving the greens with acidic toppings and complements.

  • Avoid chronic use of “acid blockers”, like Zantac, Pepsid, etc. Occasional use is safe.
  • All foods in the vegan diet, whether raw or cooked, should be chewed thoroughly to break down the cell walls. That allows maximal absorption of their minerals, including iron.
So, the take away is anyone eating lots of salads with some citrus or vinegar-containing dressing, or who snacks on soaked almonds or brazil nuts, and who avoids drinking coffee, milk, or “black” tea with their meals should not have to worry about their iron absorption.


But if there is any question, have a blood test done and see if there is any need to change your diet to optimize your iron levels.


Iron: plant vs. animal

plant sources of ironIron builds the hemoglobin molecule that carries oxygen to all your body’s cells.


Sources of Iron.      Iron comes in two forms – heme iron from animal foods and non-heme iron, from plant foods.


Heme iron is purported to be more bioavailable than non-heme iron. Studies have shown that approximately 15-35% of heme iron is utilized by the body versus only 10-20% for non-heme iron.

However, animal foods carry a lot of baggage, such as saturated fat, cholesterol, hormones, pesticides, and antibiotics, all of which increase your risk for chronic diseases.And heme iron has been shown to increase your risk for colon cancer. Not so for non-heme iron.

Common plant food sources of iron include:

  • legumes
  • vegetables: especially leafy greens
  • nuts and seeds
  • whole grains

The most common symptoms of iron deficiency include: anemia, headache, irritability, and in more severe cases, lightheadedness, shortness of breath, and weight loss.

But, don’t just rely on regular supplementation, because more is not always better.

Too much iron can increase oxidation in tissues, which promotes aging, and tissue damage to your heart, liver and pancreas.

In next week’s post I will show you how to increase iron absorption using some simple dietary “tricks”