How to Cook Spinach for Maximum Iron

Cooking spinach with tomato sauce can increase your absorption of iron.

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The U.S. Department of Agriculture's National Nutrient Database reports that spinach is rich in iron -- each cup of cooked spinach contains 6.4 milligrams of the vital mineral. For a man, that amount provides 80 percent of his recommended daily allowance of iron; for a woman, it contains 35 percent of her daily requirement. However, the iron in plant-based foods such as spinach is non-heme iron, a form that isn't absorbed as well as the heme iron in animal products. The body may absorb as little as 3 percent of the non-heme iron in spinach, says the Colorado State University Extension. By cooking spinach with certain foods though, you can maximize the amount of iron you absorb.


Use a cast iron skillet when you cook spinach, or other foods, because this can significantly increase their iron content, says Columbia University Health on the Go Ask Alice website. Heat only a small amount of oil in the skillet and use a spatula or wooden spoon to stir the spinach and increase the skillet's contact with the vegetable.


Eat spinach with an animal protein. Add poultry, pork, beef or fish, for example, salmon. Choose lean beef for the largest increase in non-heme iron absorption.


Add a food rich in vitamin C to the skillet along with the spinach. Pick a quick-cooking fruit or vegetable, such as diced tomatoes or chopped bell pepper, a small amount of tomato sauce or a drizzle of freshly squeezed lemon juice.

Things Needed

  • Cast iron skillet
  • Oil, such as olive or canola oil
  • Spatula or wooden spoon
  • Lean beef, pork, poultry or fish
  • Vitamin C-rich food, such as tomatoes, tomato sauce, bell peppers or lemon juice


  • To further increase the amount of iron you absorb from foods such as spinach, avoid drinking coffee or tea while you're eating an iron-rich meal. The tannins in these drinks can decrease iron absorption by as much as 60 percent.


  • If you're a strict vegetarian or vegan, the Institute of Medicine's Food and Nutrition Board says that you should consume more iron daily than people who eat animal products. Male vegans or vegetarians need 14 milligrams per day, while female vegans need 33 milligrams per day. Talk to a nutritionist about how to incorporate iron-rich plant foods into your diet regularly.
  • Iron deficiency is characterized by fatigue, weakness, shortness of breath and an increased heart rate. Consult your doctor if you believe that you may be deficient in iron.