IRON ON A PLANT-BASED DIET » sources & how to get enough
Iron is among the most prevalent deficiencies in the world. Your needs may differ significantly based on your gender and age. Let's scope out more information on how much you need and how to get enough.
Iron in Brief
Iron is a mineral and has several functions in the body. It’s most widely known to facilitate oxygen transport and is also a key element in DNA synthesis and the production of energy in the cells. Signs and symptoms of iron deficiency include fatigue, paleness of the skin, brittle nails, cracks in the sides of the mouth, and frequent infections. Ongoing iron deficiency may lead to iron-deficiency anemia.
Heme: One form of iron is derived from animal-based sources such as meat, poultry and fish. This form of iron is called heme iron and has high bioavailability (high absorption rates).
Non-heme: Another form of iron is derived from plant-based sources, highlighted below. This form of iron is called non-heme iron and has a lower bioavailability (lower absorption rates compared to heme-sources.
It is absolutely feasible to obtain enough iron to meet your needs from non-heme sources following a well-balanced plant-based diet.
Get some iron in your breakfast with this Creamy Steel-cut Oatmeal.
Because of the lower bioavailability of the plant-based (non-heme) sources of iron, it is recommended vegetarians/vegans consume 1.8x the amount recommended to those who consume animal products. In the table below, the values in the brackets reflect the adjusted recommendation for a vegetarian or vegan (values are sourced from these Canadian guidelines):
Men 19+ years: 8 mg daily (15 mg for vegetarians/vegans)
Women 19-50 years: 18 mg daily (32 mg for vegetarians/vegans)
Women 51+ years: 8 mg daily (15 mg for vegetarians/vegans)
Pregnant women 19-50 years: 27* mg daily (49* mg for vegetarians/vegans)
Breastfeeding women 19-50 years: 9 mg daily (16 mg for vegetarians/vegans)
Maximum: Stay below 45mg/day from food + supplement sources combined.
* Pregnant women who are vegetarian or vegan should consult with a doctor or dietitian regarding their needs, as the recommendation may be higher than the recommended maximum intake based on differences in bioavailability and absorption.
Concerned that 1.8x more for vegetarians and vegans seems unachievable? We'll explore this more below!
Try this comforting recipe, using tofu and broccoli: Spicy Garlic Wok Noodles with Stir-fried Veg & Tofu
Plant-Based Iron Sources
Values sourced from here.
¾ cup (70g) oatmeal, cooked: 4.5 - 6.5 mg
¾ cup (55g) lentils, cooked: 4 - 5 mg
1 tbsp (15ml) black strap molasses: 3.6 mg
¾ cup (150g) tempeh/fermented soy product: 3.2 mg
¾ cup (150g) tofu, cooked: 2.5 - 8 mg
¾ cup (60g) beans (most varieties), cooked: 2.5 - 5 mg
½ cup (125ml) tomato puree: 2.4 mg
½ cup (115g) spinach, cooked: 2 - 3 mg
½ cup (70g) edamame, cooked: 2 - 2.5 mg
Phytates: these are a form of “anti-nutrients” which bind to minerals in our body and render them unable to be absorbed—iron included. They are present in a variety of plant foods including vegetables, legumes, grains, nuts and seeds. It’s difficult (and should not be attempted) to avoid these foods altogether.
Suggestion: Enhance iron absorption in the presence of phytates by soaking and/or sprouting nuts, seeds and legumes. Read more on the benefits of soaking in this PUL article.
Tannins: these are compounds commonly found in black tea, espresso, coffee, or red wine. When these beverages are consumed with meals, it often decreases non-heme iron absorption.
Suggestion: If you consume these beverages, try to do so about 30 minutes before or after a meal.
Vitamin C: Foods that contain Vitamin C increase the body’s ability to absorb iron. Examples of vitamin C-rich foods include citrus fruit (oranges, lemons, limes, grapefruit), kiwis, strawberries, sweet bell peppers, potatoes, broccoli, and some green leafy vegetables.
Suggestion: combine iron-containing foods with Vitamin C-rich foods. For example, enjoy berries with your oatmeal, combine spinach with oranges in smoothies, or stir-fry tofu along with sweet bell peppers and broccoli.
Vegetarians & Vegans
Is it Possible for Vegans/Vegetarians to Get Enough Iron From Foods?
For vegans and non-vegans alike, it's important to ensure we are consuming iron-rich foods with each meal. The recommendations being 1.8x more for vegetarians and vegans may sound unachievable, but this recommendation takes into account the iron-inhibiting foods that may interfere with absorption. As long as you're generally consuming iron-rich plant-based foods with vitamin C, and drinking your tea, coffee and/or foods with phytates separately from these iron-rich foods, it's likely that you're good-to-go!
It's also important to keep in mind that vegans/vegetarians generally have lower iron stored in the body. When our iron stores are low, we're able to absorb more iron from foods. Low iron stores aren't much to be concerned about, as long as we're consistently consuming a variety of iron-rich plant-based food sources (in addition to combining it with Vitamin C-rich foods and decreasing iron inhibitors at meals and snacks). Low serum iron levels aren't much of a concern, as studies have also shown that having more iron stored in the body may not provide any additional benefit.
Check out this recipe using iron-rich lentils: Mushroom & Lentil Tacos with Creamy Garlic Avocado Sauce
A Note on Anemia
A shocking 30% of the world’s population has anemia. It’s important to note that while iron deficiency is the most significant and common cause of anemia, it is not the only one. People may become anemic as a result of other long-standing health issues irrespective of iron intake through the diet.
Women of Reproductive Age: this group has menstrual blood (and therefore iron) losses that can reach up to 50 mg per period.
Pregnant Women: there is a significant increase in iron needs during this time due to the rapid growth of the placenta and fetus(1).
Athletes: a higher requirement is generally recommended due to increased oxygen demands and greater iron losses (1).
Other: other groups that should be mindful of their iron requirements include those with medical conditions leading to chronic blood loss such as ulcers and those who have donated blood.
For those who are diagnosed with iron-deficiency anemia through a blood test, iron supplements are often recommended to resolve the issue. Once an adequate level has been reached, however, long-term maintenance is best achieved with the consistent consumption of iron-rich foods combined with foods rich in Vitamin C as opposed to ongoing supplementation (1). This is to avoid the risk of consuming excess iron, which may have negative health outcomes. As always, whenever possible, food sources are recommended before supplements.
Make this delicious Mung Bean & Spinach Salad to add in iron during lunch.
Important Notes Regarding Supplementation
General supplementation: if it’s determined you require supplementation, please see a medical doctor for a prescribed dosage and duration. The amount needed is always case-specific and taking incorrect doses can be harmful.
Multivitamins: these can also contain iron, so be observant of the amounts when calculating your total intake.
Fortification: in certain countries, commonly eaten foods are fortified with iron. For example, in Canada, products such as flour, pasta and breakfast cereals are fortified with iron. It is worth checking if foods in your country are fortified and to take this into account when assessing your intake.
Doctor's orders: we only recommend taking if recommended by your family physician or dietitian, as there are some negative consequences to taking too much. If you're unsure, see your family doctor for support.
As briefly mentioned in the previous sections, consuming too much iron can have several negative health outcomes:
constipation or diarrhea
increased risk of disease (i.e. heart disease)
increased production of free radicals and oxidative damage
It's unlikely to overload on iron if we're getting iron from plant-based sources because the nonheme iron absorption is controlled. Taking iron supplements, on the other hand, increases the risk of overloading on iron, so we generally recommend consistent consumption of iron-rich foods for long-term maintenance of iron levels.
(1) Davis, Brenda, and Vesanto Melina. "Becoming Vegan: the Compete Reference on Plant-Based Nutrition." Becoming Vegan: The Complete Reference on Plant-Based Nutrition, Book Publishing Company, 2014, pp. 186-189.
Want to Learn More?
Read this previous nutrition article called Calcium on a Plant-Based Diet: everything you need to know.
❤ Written by: Mitra (Executive Assistant and Dietetic Student) and Sadia