Prevent iron deficiency on a vegan diet

How can you prevent iron deficiency on a vegan diet? Let’s find out.

Functions of iron

Iron is an essential element for life. Above all, our red blood cells need it for oxygen transport. Iron deficiency affects billions of people worldwide and has a significant negative impact on the immune system. The people most at risk are women and children.

In women, menstrual blood loss (rather than their diet) is a major determining factor in iron status.

While non-menstruating women and men lose 1 mg of iron daily, menstruating women lose 10 to 42 extra mg per menstrual cycle.

Heme and nonheme iron

Food is the only source of iron for the human body. There are two forms: heme and non-heme iron. Heme iron is found in meat and nonheme iron is found in plant products, such as beans, lentils, nuts and greeny leaves.

Vegan and vegetarian diets contain only nonheme iron.

Absorption of heme iron is efficient and largely unaffected by other nutrients. However, high heme iron intake from animal sources has been linked to type 2 diabetes, obesity, metabolic syndrome and increased production of free radicals. The heme iron in animal products undergoes a reaction with hydrogen peroxide in the body, producing harmful oxygen radicals. This can lead to DNA damage, which increases the risk of cancer.

On the other side, nonheme iron has a lower absorption (bioavailability), because it exists in an oxidized form which cannot cross the intestinal wall, but needs to be reduced first.

Luckily, the body can adapt to solely relying on non-heme iron.

Iron status of vegans

Iron deficiency is the most common deficiency worldwide. Symptoms that occur with an iron deficiency are fatigue, dizziness, hair loss and headache. If iron intake is insufficient for a longer period of time, there is a risk of iron deficiency anemia.

Various studies found that vegetarians consume more iron than omnivores, and vegans consume the most iron. Despite the higher iron intake, in some studies, vegans and vegetarians have lower iron stores in the body than meat-eaters. This was probably due to the lower bioavailability. Luckily, adverse health effects of lower iron absorption have not been demonstrated with varied plant-based diets.

Advice to prevent iron deficiency on a vegan diet

The daily recommendation for the iron intake is 16 mg for women and 11 mg for men.

Many sources say that vegans need to consume 1.8 times more iron than non-vegans because of the lower bioavailability of nonheme iron. However, this conclusion is based on very limited research from the 90’s. Longterm prospective studies are still needed to accurately determine the iron needs of vegans.

For now, you can rest assured that your body will adapt to non-heme iron and increase the absorption as needed. Also, vitamin C can improve your iron status even more than an iron supplement.

Plant foods which are good sources of iron include: amaranth, quinoa, whole grains, sesame seeds, sunflower seeds, pine nuts, almonds, tofu, kidney beans, lentils, chickpeas, spinach and parsley.

Inhibitors

Absorption of nonheme iron is modifiable by a number of inhibitors and promoters. Polyphenols can diminish nonheme iron absorption. They are found in herbs and spices, such as herb tea, black tea, coffee, rosemary, oregano, basil and chili. Also, foods containing phytates, such as whole grains and legumes, can compromise the absorption of nonheme iron. In addition, calcium-rich products inhibit the absorption of both heme iron and non-heme iron.

Promoters

Vitamin C and β-carotene are strong promoters of nonheme iron absorption. Intake of vitamin C and β-carotene is usually high among vegans and vegetarians, thus potentially compensating for the low bioavailability of nonheme iron. Other known factors enhancing iron absorption are fermented products and products made from fermented soy beans.