Increase Iron With Food
By Rhianna Ross, RHN
Iron is a very important nutrient, especially for growing infants, toddlers, and children. Without adequate amounts of iron, a child’s growing body and brain may not meet their full potential.
It can be hard to ensure your child is getting enough iron through food sources alone. Especially since children are often very picky eaters. And while supplements are essential when dealing with iron deficiency and iron deficiency anemia, regularly eating iron-rich foods will help to raise and sustain your child’s iron levels.
There are two forms of iron found in food:
- Non-heme – found in grains, animal meats, egg whites, dairy, beans, nut, seeds, fruits, and vegetables.
- Heme – found in animal meats, poultry, egg yolks, and fish. Heme iron comes from the protein hemoglobin found in red blood cells in animal meats. Myoglobin also provides iron. Myoglobin is another protein found in the muscle tissue of animal meats.
Heme iron is much easier for humans to absorb. Approximately 15 to 35 percent of heme iron is absorbed. Because vegetarians and vegans do not consume animal products, they are at a greater risk of iron deficiency and iron deficiency anemia. We only absorb about 2 to 20 percent of non-heme iron.
Iron is an essential mineral used in many important functions in your child’s body including:
- Growth (height) and development
- A healthy immune system
- The manufacturing of healthy red blood cells and hemoglobin
- Energy levels in the body
- Cognition and achievement at school
- Emotional and mental wellbeing
- The manufacture of hormones like serotonin (the happy hormone)
In humans:
Hemoglobin is an iron-containing protein found in red blood cells, which delivers oxygen to the cells of the body. Hemoglobin helps maintain the normal size and shape of red blood cells.
Myoglobin is an iron-containing protein similar to hemoglobin that binds with oxygen, however this protein is only found in muscle cells and myoglobin provides oxygen and energy to muscles.
Ferritin is a protein that stores iron. High levels of ferritin are found in the spleen, liver, skeletal muscle and bone marrow.
High Iron Foods
Foods that are highest in heme iron include:
- Shellfish (clams, oysters, mussels, squid)
- Organ meats (liver, kidney)
- Meat (chicken, lamb, pork, beef, venison)
- Fish (sardines, anchovies, mackerel, trout)
Foods highest in non-heme iron include:
- Lentils and legumes (soak before cooking)
- Leafy greens (spinach, kale, and chard)
- Vegetables (Brussels sprouts, podded peas, broccoli, asparagus, squash)
- Dried apricots, raisins, figs, peaches
- Seeds and nuts (soak before cooking)
While the foods above may contain high levels of iron, there are many substances that we consume in our diet that can greatly hinder the absorption of iron.
Foods that Hinder Iron Absorption
Many of the healthy foods we eat contain substances that reduce the absorption of iron.
If you are a meat eater you have less of a concern about iron-inhibiting substances because you are eating more easily absorbed heme iron. Most of the iron-inhibiting compounds we mention below only hinder the absorption of non-heme iron, with the exception of calcium and dairy products, which block the absorption of heme iron as well.
The foods and nutrients listed below should not be completely avoided as some of these foods have their own health benefits. However, vegetarians and vegans should consider reducing or limiting the consumption of iron-inhibiting foods.
Calcium
Calcium is an essential mineral important for growing children so it must be included in the diet. However, high calcium-containing foods should be eaten away from iron-containing foods because calcium hinders the absorption of both heme and non-heme iron. High calcium foods include canned fish like salmon that contain bones, and milk and milk products like cheese and yogurt.
Dairy
Because dairy contains both calcium and iron-blocking proteins, it is best to avoid consuming dairy near iron-containing foods. Dairy should not be introduced before 12 months of age. Avoid giving your child cow’s milk if they are iron deficient or anemic.
Caffeine
Found in chocolate, soft drinks, tea, and coffee. Caffeine interferes with the absorption rates of multiple nutrients, including iron.
Oxalate
Oxalates are compounds derived from oxalic acid and found in fruits such as rhubarb and strawberries; vegetables like kale, spinach, and beets; tea, chocolate, nuts, and seeds; and herbs such as oregano, basil, and parsley. Oxalates and minerals can bind together in the digestive system and hinder absorption. Oxalates can be reduced in vegetables by cooking, boiling, or steaming.
Phytic Acid
Phytate compounds are found in seeds, nuts, some grains, and beans. Phytic acid can reduce iron absorption by 50 to 65 percent. In addition to iron, phytic acid hinders calcium, magnesium, and zinc absorption. As an antioxidant, phytic acid is beneficial to health. Antioxidants help to protect our cells from damage. Phytic acid-containing foods typically contain high amounts of fibre, which can be protective against colon cancer and should not be avoided. Phytic acid in foods can be reduced by soaking, sprouting, or fermenting foods.
Polyphenols
Polyphenols are found in a wide variety of plant foods including fruits, vegetables, legumes, herbs, spices, herbal and black teas, coffee, and wine. There are different types of polyphenols such as flavonoids, resveratrol, and curcumin. Like phytic acid, polyphenols have many health benefits and should not be avoided. However, polyphenols do hinder the absorption of heme iron and can cause issues for those who are anemic if they are consuming large amounts near iron-containing foods. To reduce the effects of polyphenols on iron, leave a few hours between high iron meals and high polyphenol meals.
Protein
Certain proteins can reduce iron absorption such as casein found in milk, phosvitin found in eggs, and the protein found in soybeans and soy products. Such proteins should be eaten away from high iron foods.
Ways to Increase Iron Absorption
Soaking, Sprouting, and Fermenting
Vegetable sources of iron are poorly absorbed because vegetables, grains, and legumes contain ingredients like oxalate, phytates, and polyphenols that inhibit the absorption of iron. Vegetarians and vegans should get in the practice of soaking or sprouting foods or eating fermented foods because they do not eat the more easily absorbed heme iron found in animal meats, poultry and fish.
Soaking or sprouting nuts, seeds, legumes, whole grains, and lentils can reduce these iron-blocking substances thereby increasing the bioavailability of non-heme iron and other nutrients found in those foods. If you are eating a lot of animal meats, fish, or egg yolks, you are consuming easily-absorbed heme-iron containing foods and phytates and oxalates will have little effect on heme iron absorption. However, soaking is still beneficial for those who have difficulty digesting legumes or those who are very low in iron or other minerals such as magnesium.
Fermentation of foods helps breakdown the phytates found in grains, nuts, seeds and vegetables.
Iron-Boosting Nutrients
Vitamin C helps to increase the absorption rate of iron. Include foods that are high in vitamin C when eating foods that are high in iron. Foods high in vitamin C are kiwis, kale, bell peppers, broccoli, Brussels sprouts, citrus fruits, papaya, and strawberries. Vitamin C given in a 50 mg dose was found to increase iron absorption by 67 percent.
Vitamin A
Vitamin A helps to increase non-heme iron absorption and protects iron from phytates and polyphenols that can hinder non-heme iron absorption. A deficiency in vitamin A may increase the risk of iron deficiency. Ensure the diet includes sources of vitamin A such as beef, lamb, fish, mackerel and salmon. Beta carotene, which is converted to vitamin A, is found in brightly coloured orange, red, and green vegetables.
Meat
Eating animal foods increases the absorption of non-heme iron. Eating animal meat or fish with vegetables, legumes, or grains that contain iron will make the non-heme iron more available to the body. We always recommend organic and free-range poultry, organic and grass-fed beef, and wild fish over farmed.
Food Labels
Food labels should provide a list of vitamins and minerals. Labelling guidelines require iron to be listed. The amount listed does not mean how much your body is actually absorbing. In fact, we absorb much less than what is stated on a food label. Amounts listed on the label do not take into account the other substances we discussed above that can hinder absorption. The amount we absorb is dependant on current iron stores in the body, our digestive health, and the presence of substances that either increase or decrease the rate of iron absorption. Heme iron has an absorption rate of 15 to 35 percent, while non-heme has a rate of 2 to 20 percent depending on these factors. Therefore, iron intake from food sources will need to be greater than the recommended amount to account for the rate of absorption.
We should be eating a minimum of 20 mg of iron from our diet daily but most of us, especially children are eating much less than this amount. The charts below give the amount of iron found in common iron containing foods. It is important to remember that your child will not absorb 100 percent of the iron they eat.
Iron in Food
A 75 gram serving is equivalent to roughly a pack pf playing cards.
| Food | Heme Iron (mg) per 75 g serving |
| Chicken Liver | 9.2 |
| Oysters | 6.3 |
| Mussels | 5 |
| Beef | 4.8 |
| Clams | 2.1 |
| Lamb | 1.5 |
| Tuna, herring, trout, mackerel | 1.2 |
| Chicken | 0.9 |
| Shrimp | 0.9 |
| Turkey | 0.5 |
| Salmon | 0.5 |
Did You Know?
We only absorb around 2 to 20 percent of iron found in plant foods.
| Food | Serving | Non-Heme Iron (mg) |
| Lentils (cooked) | ¾ cup | 4.9 |
| Pumpkin seeds | ¼ cup | 4.7 |
| Red kidney beans (cooked) | ¾ cup | 3.9 |
| Spinach (cooked) | ½ cup | 3.4 |
| Chickpeas (cooked) | ¾ cup | 2.2 |
| Swiss chard (cooked) | ½ cup | 2.1 |
| Quinoa cooked | ½ cup | 1.5 |
| Rolled Oats | ½ cup | 1.7 |
KidStar® BioFe® Iron
KidStar® BioFe® is gentle and will not upset sensitive stomachs or stain teeth like common iron supplements.
The iron in BioFe® is micronized and microencapsulated, protecting you from the side effects of iron, like constipation, black stools, tummy upset, and grey teeth. Microencapsulation also allows BioFe™ iron to be taken at the same time as foods and nutrients containing calcium.
KidStar® BioFe® Iron is available in a tiny chewable tablet. Like all KidStar® nutrients, our iron supplements do not contain sugar, artificial colors, artificial sweeteners and artificial flavors, soy, gluten and GMOs.
Putting it all Together
- Combine foods high in non-heme iron with heme iron foods if possible
- Combine vitamin C foods with high-iron foods
- Include foods rich in beta carotene or vitamin A
- Soak whole grains, nuts, seeds, lentils, and legumes before eating
- Eat fermented foods
- Avoid including dairy products or high-calcium foods with high-iron foods
- Eat iron-rich foods before or six hours after a hard workout (after exercise, inflammation hinders absorption)
- Avoid drinking herbal or black teas near iron meals
- Cook dark leafy greens like spinach or chard before eating
- Include an iron supplement
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About the Author
Rhianna Ross, R.H.N., is a registered holistic nutritionist based in Vancouver, BC. Rhianna has more than a decade of experience in the natural health and wellness industry, and currently works at KidStar Nutrients, where she enjoys reviewing and analyzing the latest nutritional research papers, meta-analyses, and journal articles.