Iron is absolutely crucial for our health. The mineral is used to make both hemoglobin, a protein found in blood that carries oxygen from the lungs all over the body, and myoglobin, a protein that provides the muscles with oxygen.
Chances are, you grew up being told that it’s best to get iron from animal sources. Lately, though, plant-based advocates (like that vegan dietitian or bodybuilder you started following on Instagram) have been shouting from the rooftops that we’ve had it all wrong.
So what gives? We tapped nutritionists to learn more about the essential mineral and whether you can really get enough of it on a plant-based diet.
A Tale Of Two Irons: Heme vs. Non-Heme
First of all, how much iron you need daily depends on factors like your age, sex, and stage in life. While the National Institutes of Health recommends adult men and postmenopausal women get eight milligrams per day, for example, premenopausal women need 18 and pregnant women need 27. (You can see the full chart here.) So, knowing how much iron you need to thrive is an important first step.
Read More: 6 Signs You’re Not Getting Enough Iron
Regardless of age, sex, and stage in life, though, vegetarians need 1.8 times more iron per day than those who regularly consume meat. Why? “Plant-based iron-rich foods are not as bioavailable to the body, meaning that our bodies cannot absorb iron from these foods as easily,” explains plant-based dietitian Tiffany Ma, R.D.N.
Here’s the deal: Plants contain what’s called non-heme iron, while animal foods offer heme iron. While the iron in animal foods is generally easy for the body to absorb, the iron in plants is often bound to other compounds, like phytates, that make it harder for the body to access.
“Plants and animals are both sources of iron, but it’s not about iron content, it’s about absorption—and the absorption of iron from plants is lower, so you need more,” says Keith-Thomas Ayoob, R.D., FAND, of the Albert Einstein College of Medicine (who considers himself a plant-based omnivore.)
As a result, research has shown that, while vegetarian diets can be nutritious and healthful, non-meat eaters tend to have lower hemoglobin levels and are more likely to be anemic.
How To Boost Your Absorption Of Plant-Based Iron
Thankfully, you can increase your absorption of that plant-based iron with a simple technique: Pair your iron-rich eats (such as beans or dark, leafy greens) with a source of vitamin C, like an orange.
In fact, research suggests that you absorb the iron in both foods and supplements better when you consume it alongside vitamin C. Just 25 to 100 milligrams of vitamin C (which is about half a cup of red bell pepper, a medium kiwi, or half a cup of cooked broccoli) can increase your iron absorption four-fold.
Vitamin C works this magic by way of a mineral called ascorbate, which is one of its byproducts. “Ascorbate plays a role in passing between intestinal cells, and, in doing so, reduces iron (often non-heme) to a form that is more readily absorbed, helping transfer iron to transferrin,” explains Gillespie. “Transferrin is a protein that delivers iron to cells.”
If you pair every non-heme iron source with some vitamin C, you probably don’t need to consume double the iron of a meat-eater in order to meet your needs, Gillespie says. Still, it’s worth consuming enough iron-rich plant foods to surpass your needs. “Many things impact absorption, so without routine lab monitoring, we can’t really effectively evaluate one’s degree of absorption,” Gillespie explains. For that reason, she recommends aiming for 1.25 the daily recommended amount.
How To Get Enough Iron While Eating Only (Or Mostly) Plants
Thankfully, with a little effort and some careful planning, experts say it’s completely possible to get enough iron on a plant-based diet.
Keep these tips in mind to make sure you’re meeting your needs without the meat.
1. Include iron-rich foods in every meal
A meat-eater can put a serious dent in their daily iron needs with just one steak, which provides six milligrams of iron, says Diana Gariglio-Clelland, R.D., a dietitian with Next Luxury. However, for a vegetarian to get the same amount, they’d have to eat two cups of cooked lentils. (Plus, if you shoot to surpass your daily iron needs just to be safe, those lentils don’t get you quite as far.)
To at least hit their iron intake goal, vegetarians and vegans should make a conscious effort to eat iron-rich foods with every meal, Gillespie says. Some smart choices include:
- Beans and legumes (4.4 to 6.6 milligrams of iron per cooked one-cup serving)
- Leafy green vegetables (2.5 to 6.4 milligrams of iron per one cup, cooked)
- Nuts (1 to 1.6 milligrams of iron per one-ounce serving)
- Seeds (1.2 to 4.2 milligrams per two-tablespoon serving)
Here’s what a typical day of iron-rich eats might look like, according to Ma:
- 1/2 cup lentils: three milligrams
- 1/2 cup tofu: three milligrams
- 1/2 cup kidney beans: two milligrams
- 1 medium potato: two milligrams
- Half a serving of fortified breakfast cereal: nine milligrams
Check all of these boxes, and you’ve got 19 milligrams of iron.
2. Get your iron tested regularly
If you haven’t already taken the plant-based plunge, now’s a good time to check up on your iron levels. Your doctor can perform a simple blood test, called a complete blood count (CBC) test, to measure your hemoglobin and hematocrit, which is the proportion of red blood cells in your blood, so that you know where you stand.
After you’ve established your baseline, Ayoob recommends following up with another test every six months or so to keep an eye on your iron status. This way, you have some information in your pocket to help you adjust your eats or decide you need help from a dietitian.
3. Don’t forget the vitamin C
Now that you know how important vitamin C is for making the most of plant-based iron, consider this: “One study suggests that in order to promote better absorption, you should consume 20 milligrams of vitamin C per every three milligrams of iron,” says Gariglio-Clelland. “This means that the more iron in the meal, the more vitamin C you need to boost absorption.”
So, if you eat one cup of cooked white beans (which offers around five milligrams of iron), you’d need around 33 milligrams of vitamin C to boost absorption, Gariglio-Clelland says. Luckily, even half a cup of bell pepper offers about twice that, so you’ll be covered without having to do too much math.
Generally, as long as you include a solid source of vitamin C or two in each meal, you’ll be just fine.
4. Consider supplementing
One major reason to get that bloodwork done regularly: It can help you (along with your doctor or nutritionist) determine if (and how) you should supplement with iron.
“If you are following a plant-based diet and don’t consume fortified foods or are particularly picky with your food, an iron supplement can certainly be helpful,” says Ma. Talk to your healthcare provider to figure out just how much per day you might need to take.
5. Take note of whether you need more iron than most people
In addition to eating plant-based, there are a handful of other life factors that might indicate you need even more iron than addressed here. “Not only is iron an important micronutrient for those who follow plant-based diets, but those who are menstruating, pregnant, lactating, those who donate blood regularly, and those who are physically active should also evaluate their iron intake,” says Ma. “Those who follow plant-based diets and also meet any of these criteria above definitely need to be much more [attentive] than the average healthy individual.”
If any of these apply to you, check in with a dietitian to get clear on your unique daily iron intake needs and how you can meet them.
6. Keep an eye on calcium
Not-so-fun fact: Calcium-rich foods may inhibit iron absorption, so you’ll want to be wary of how much of each mineral a given snack or meal contains, according to Gillespie.
“Focus on separating calcium-rich foods and iron-rich foods as much as possible; maybe focusing on iron-rich foods during meals and calcium-rich foods as snacks in between meals, or vice versa,” Gillespie suggests. Since some plant-based foods are good sources of both iron and calcium (such as leafy greens and soy), you can’t always avoid this—but don’t stress!
Read More: 6 Calcium-Packed Foods That Aren’t Dairy
“For instance, just save your calcium-fortified milk for after your iron-rich meal,” Gariglio Clelland says. You might also want to be wary of fortified cereals and juices, and any dairy or fish you incorporate into your diet.