Top Tips to Boost Iron Intake and Absorption


By Chris Rosenbloom, PhD, RD, CSSD

Swimmers need adequate iron for performance. Iron is the key part of the blood protein hemoglobin. Its job is to pick up oxygen from the lungs and transport it to working muscles. Without enough hemoglobin your muscles don’t get enough oxygen. The result? You won’t have the ability to exercise for long periods of time or at high intensity and you will feel increasingly tired with even moderate exercise.


Some studies show that your maximal oxygen update (a measure of aerobic capacity) can be reduced as much as 50% with severe anemia. Iron comes in two forms—heme and non-heme. Heme iron is found in meat and seafood (beef, pork, lamb, poultry, fish and seafood) and about 15-35% of this type iron is absorbed. Non-heme iron is found in plants (breads, cereals, rice, pasta, soy, dairy foods, and vegetables) is poorly absorbed at only 2-15%.

Here are the top tips for getting enough iron in your diet along with tips to help maximize the absorption of iron from the gut.

1. Small amounts of meat matter. Even if you prefer a plant-based, semi-vegetarian diet, small amounts of meat, fish or poultry can enhance iron absorption. They contain something that scientists call the “MFP factor” for meat, fish, and poultry. We’re not sure what it is in these foods that improve iron absorption, but include small amounts (3-ounces or the size of a deck of cards or a computer mouse) in a pasta sauce, a stir-fry, or a green salad. Lean beef in spaghetti sauce, tuna chunks in pasta salad, fish tacos, or a chicken drumstick all contain the most absorbable form of iron.


2. Add Vitamin C. Ascorbic acid (Vitamin C) is a potent enhancer of iron absorption. It can change iron to a more absorbable form—up to three times more iron can be absorbed when food is eaten with a good source of Vitamin C. In addition, it can improve iron absorption in both heme and non-heme sources. Easy ways to add vitamin C include drinking orange juice with breakfast, adding green or red peppers and broccoli to a beef or chicken stir-fry, slicing strawberries on your breakfast cereal, and eating a citrus fruit salad with a tuna fish sandwich.


3. Don’t self-diagnose iron deficiency and take supplements without a physician’s recommendation. The only way to know for sure if you have iron deficiency is to get blood work to check for iron deficiency (checking hemoglobin and hematocrit) or iron depletion (checking ferritin or the storage form of iron). Supplementing with iron without depletion or deficiency is a bad idea….iron is a pro-oxidant and could cause long term health issues.

Preventing iron deficiency is better than treating it, so take a food first approach and get adequate iron-rich foods with every meal.


Chris Rosenbloom is the sports dietitian for Georgia State University Athletics and is the editor of the Academy of Nutrition and Dietetics Sports Nutrition Manual, 5th edition, 2012. She welcomes questions from swimmers, parents and coaches. Email her at

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