Locations:
Search IconSearch

What Iron Does for Your Body

The benefits of iron span your whole body, from your blood and your brain to your immune system and more

Person holding up and pointing to bowl of tofu, with assorted protein foods floating around

What is iron?

Iron is an important nutrient in our diets. So critical, in fact, that many foods, from infant formula to breakfast cereals, are commonly fortified with iron to help ensure we get enough of it.

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

But there are risks to getting too much iron.

How can you make sure you get the right amount? And why does iron matter so much?

We talked with registered dietitian Lisa Reitz, RD, LD, about the benefits of iron and how to make sure you get the right amount of it in your diet.

Iron benefits

One of iron’s top jobs is to provide oxygen to your body.

Here’s how.

Iron helps your body to produce hemoglobin, a protein in your red blood cells. Hemoglobin carries oxygen from your lungs to the rest of your body.

Iron also helps create the protein myoglobin, which provides oxygen to your muscles.

“When we don’t have enough iron, our red blood cells can’t transport oxygen as well,” Reitz says.

In fact, people who have an iron deficiency have smaller red blood cells. That’s because their blood has less hemoglobin and less oxygen to plump them up.

It’s a domino effect. Too little iron means too little hemoglobin and myoglobin. Too little hemoglobin and myoglobin means too little oxygen coursing through your body. And too little oxygen can spell trouble.

Reitz shares just a few ways that our iron intake affects our health.

Keeps energy levels up

Your body uses oxygen for energy. And iron helps make sure your body gets the oxygen it needs to keep your energy levels up.

Advertisement

“Symptoms like fatigue and lightheadedness can have a lot of causes. And having low iron or iron-deficiency anemia is one of them,” Reitz shares. “Your body needs iron to help keep up with the demands of life.”

Aids brain health

Your brain cells need a steady stream of oxygen-rich blood to function at their best. Iron helps ensure that oxygen-rich blood gets to those cells.

Oxygen is a catalyst that helps your brain do things like build nerves, make and break down chemicals that allow your nerves to communicate, and keep your brain working in tip-top shape.

So, when you don’t have enough iron to supply oxygen to your brain, it can cause trouble.

Boosts immunity

Iron helps keep your body moving and grooving through its daily processes. So, when you have less iron — and therefore, less oxygen — flowing through your system, some other tasks can fall by the wayside. That can include things like keeping up your immune system.

“People who have iron deficiency anemia can be less able to fight off certain infections and germs,” Reitz explains. “If you're not getting enough oxygen through your body, your body has to work harder just to try to keep going with the day to day. And things like your immune system can suffer.”

Think about it. When you’re overtaxed with work, kids’ after-school commitments and other obligations, the dishes might start to pile up. Or the laundry might go undone. We all make tradeoffs in our lives. And your body does the same.

Healthier hair

For some people, one of the first signs that your iron is low can be a change in your hair. Or more specifically, the loss of it.

Remember those tradeoffs we make? When your body chooses between sending its limited oxygen supply to your vital organs or your hair follicles, your organs win out.

Less blood and oxygen to your hair follicles can damage them and cause you to shed more hair.

How much iron you need

Here’s a look at the recommended dietary allowances for iron (in milligrams):

Age
Birth to 6 months
Males
0.27 mg
Females
0.27 mg
Pregnancy
Lactating
7 to 12 months
Males
11 mg
Females
11 mg
Pregnancy
Lactating
1 to 3 years
Males
7 mg
Females
7 mg
Pregnancy
Lactating
4 to 8 years
Males
10 mg
Females
10 mg
Pregnancy
Lactating
9 to 13 years
Males
8 mg
Females
8 mg
Pregnancy
Lactating
14 to 18 years
Males
11 mg
Females
15 mg
Pregnancy
27 mg
Lactating
10 mg
19 to 50 years
Males
8 mg
Females
18 mg
Pregnancy
27 mg
Lactating
9 mg
51+ years
Males
8 mg
Females
8 mg
Pregnancy
Lactating

The World Health Organization (WHO) calls iron deficiency anemia the most common nutritional deficiency in the world, estimating that it affects 30% of people across the globe. It’s more common in regions where foods aren’t fortified with iron. But it can affect anyone.

Iron deficiency is also more common in people who are pregnant. That’s because, during pregnancy, you create more red blood cells to support healthy fetal development. That means you need more iron to make sure those blood cells get the oxygen they need. A healthy pregnancy diet should include plenty of iron. And be sure to choose a prenatal vitamin with adequate iron

You also need more iron during your menstruating years to counteract the loss of blood in each menstrual cycle. People who experience higher-than-average periods may be at risk for iron deficiency.

Advertisement

The same is true for other people who experience high amounts of blood loss, such as some people living with cancer or people who donate blood often.

What’s more, certain medications, like proton pump inhibitors, commonly used for chronic acid reflux and stomach ulcers, can keep your body from absorbing iron properly, which can leave you at risk for deficiency.

Getting more iron on your plate

Your body doesn’t make iron on its own. It has to get it from the foods you eat. Luckily, lots of foods are good sources of iron. Here are some of the top sources:

Food
Fortified cereals
Serving size
1 serving (per brand’s nutritional label)
Milligrams (mg) per serving
18 mg
Percent daily value
100%
Cooked Eastern oysters
Serving size
3 ounces
Milligrams (mg) per serving
8 mg
Percent daily value
44%
Canned white beans
Serving size
1 cup
Milligrams (mg) per serving
8 mg
Percent daily value
44%
Beef liver
Serving size
3 ounces
Milligrams (mg) per serving
5 mg
Percent daily value
28%
Lentils
Serving size
1/2 cup
Milligrams (mg) per serving
3 mg
Percent daily value
17%
Boiled spinach
Serving size
1/2 cup
Milligrams (mg) per serving
3 mg
Percent daily value
17%
Firm tofu
Serving size
1/2 cup
Milligrams (mg) per serving
3 mg
Percent daily value
17%

Types of dietary iron

Not all iron that you get from food is created equally. In fact, the iron you get from animal sources and the kind you get from plant foods are different.

  1. Heme iron comes from animal sources.
  2. Non-heme iron comes from plant sources.

The difference — perhaps surprisingly — has to do with vitamin C. Think of vitamin C as a buddy that helps your body properly use the iron available in your plant foods.

“Heme iron comes from food sources that also contain vitamin C, which helps the iron to be more easily absorbed,” Reitz explains. “Non-heme iron will be better absorbed if you eat it along with foods that contain vitamin C.”

That could be foods like:

Advertisement

Should you take an iron supplement?

Reitz suggests caution when considering iron supplements.

Why? Iron is clearly important to your health, so it would seem natural to assume that more iron means better health. And what could be an easier way to get more iron in your life than to pop an iron supplement.

But iron supplements aren’t right for everyone.

“There is an upper limit to recommended iron intake. That’s because too much iron, particularly from supplements, can affect zinc absorption. And it can affect your stomach, from nausea and vomiting to significant damage to your GI tract,” clarifies Reitz.

You’re very unlikely to eat your way to toxic levels of iron. But with iron supplements, it can be easy to overdo it.

The National Institutes of Health shares these upper intake levels for iron:

  • Age 13 and younger: 40 mg.
  • Age 14 and older: 45 mg.

The safest route to getting the right amount of iron is to stick to a “foods-first” mentality. That’s to say: Choose foods that will give you the vitamins and nutrients that your body needs.

And if you worry that you’re not getting enough iron in your diet, talk with a healthcare provider, like a registered dietitian.

“An iron supplement may be beneficial to some people who don’t get enough iron in their diet,” Reitz notes. “But I always urge people to talk with a healthcare provider before starting any supplement. They’ll be able to best advise you to make sure you’re getting the right amount of nutrients and take into account any health conditions or medications that may affect your needs.”

Advertisement

Learn more about our editorial process.

Related Articles

Arms of person bent down examining food in a bottom-of-fridge freezer bin
November 29, 2024/Nutrition
Spoiler Alert: Refrigerated Food Can Go Bad During a Power Outage

Extended outages lasting more than four hours can make food in your fridge unsafe to eat

Smiling mother looking down on baby breastfeeding
November 8, 2024/Nutrition
Intermittent Fasting While Breastfeeding: Is It Safe?

Intermittent fasting could impact your milk supply and energy levels, so it’s best to wait until you’ve weaned your baby from nursing

Adding spoonful of allulose to mug of coffee
November 4, 2024/Nutrition
What You Need To Know About Allulose

Although allulose is an FDA-approved sugar substitute, more research is needed to understand its safety

Person in park wearing fitness apparel, drinking water from bottle, with person walking and person on bench in background
October 3, 2024/Nutrition
How Much Water You Should Drink Every Day

Consumption needs vary based on activity, weather, metabolism and other factors

A plate on table divided into balanced nutrition sizes, with fork and knife, and a spot on the table for dairy
September 27, 2024/Nutrition
What Exactly Is a Balanced Diet?

A typical recommended balanced diet is half fruits and veggies, a quarter protein and a quarter grains

Person wearing glasses sitting on couch holding laptop, rubbing eyes, looking tired
September 9, 2024/Primary Care
6 Signs You May Be Iron-Deficient

Experiencing constant fatigue, shortness of breath and chills could all be signs of low iron

Person in kitchen holding placard with six foods containing calcium, like tofu, broccoli and almonds
September 6, 2024/Nutrition
Food for Your Bones: How To Follow the Osteoporosis Diet

Eating enough dairy, fish and leafy greens is a good way to help keep your bones strong

Tofu and vegetables in enamel serving skillet
August 27, 2024/Nutrition
What You Need To Know About the Ornish Diet

This low-fat, plant-based eating plan includes lifestyle changes, such as exercise, stress management and social support

Trending Topics

Person touching aching ear, with home remedies floating around
Home Remedies for an Ear Infection: What To Try and What To Avoid

Not all ear infections need antibiotics — cold and warm compresses and changing up your sleep position can help

Infographic of foods high in iron, including shrimp, oysters, peas, cream of wheat, prunes, eggs, broccoli, beef and chicken
52 Foods High In Iron

Pump up your iron intake with foods like tuna, tofu and turkey

Person squeezing half a lemon into a glass of water
Is Starting Your Day With Lemon Water Healthy?

A glass of lemon water in the morning can help with digestion and boost vitamin C levels, and may even help get you into a better routine

Ad