When you think “prenatal vitamin,” the first word that probably comes to mind is folate, aka folic acid. (At least, it does when you’re a health writer like me.) 

Folate is the star of most discussions surrounding prenatal nutrition because it plays such a huge role in the early development of a fetus. But that doesn’t mean that there aren’t other important vitamins and minerals to prioritize in your diet when you’re pregnant or trying to conceive. One that deserves more attention ASAP: iron. 

Why is iron an important mineral? 

Iron secretly facilitates one of the most important processes in your body. The mineral is the key component of hemoglobin, a protein that binds oxygen to red blood cells so that it can be carried throughout your body. Your body then uses that oxygen to convert food into energy so that you can do all the things you need to do to function. Iron is also an important part of the protein myoglobin, which carries and stores oxygen in your muscles

There are generally two kinds of iron: heme iron, which typically comes from meat, and non-heme iron, which comes from plant foods and vitamins. (More on that later.) 

According to the National Institutes of Health (NIH), adult women need to consume about 18 milligrams of iron per day. If you don’t get enough iron, you could start to feel weak and tired and have issues concentrating or remembering things. You might also have a harder time fighting off illnesses. Women, particularly those of us who are pregnant, have given birth, or have heavy periods, are more likely to be iron deficient than men. 

In more serious cases, being critically low in iron can cause anemia — when your body doesn’t have enough red blood cells or hemoglobin to deliver oxygen. People with anemia can have fatigue, get dizzy, and have cold hands and feet. 

Why is iron important when you’re trying to conceive? 

Iron is critical for preventing anemia when TTC — especially in people who have heavy menstrual periods, says Dorothy Bestoyong, DO, an OB/GYN and a Rescripted Expert. She adds that the mineral also supports your thyroid — which can cause fertility issues if it’s not functioning properly. 

“It’s always important to be tested for thyroid function as well as iron levels prior to conception or trying to conceive to evaluate if there’s anything that needs to be corrected or supplemented,” she says.

There is some mixed evidence that taking iron (whether by food or through supplements) might help improve your chances of conceiving. A 2006 study, which studied thousands of women without infertility for eight years, found that women who took non-heme iron supplements had a significantly lower risk of ovulatory infertility (infertility caused primarily by issues with ovulation) than women who didn’t. 

However, another study in 2019 published in The Journal of Nutrition found that there wasn’t much of a consistent connection between fertility and dietary iron intake in most women, except for those who were at risk of iron deficiency. (And in that case, it was mainly the non-heme variety that was potentially beneficial.) So don’t think of iron supplementation as a silver bullet for infertility.     

Why is iron important during pregnancy? 

Again, iron is really important to prevent anemia — something to which pregnant women are especially vulnerable, Dr. Bestoyong says. 

According to the American College of Obstetricians and Gynecologists (ACOG), your body also really needs iron to help make the extra blood needed during pregnancy. (Remember, you’re growing a whole human who needs their own blood!) Iron will also help deliver oxygen to you and your fetus to support their growth and health. Your growing fetus also needs iron for brain development

For all of those reasons, the NIH recommends that pregnant women get 27 milligrams of iron per day during pregnancy

How do you get enough iron during these key periods? 

The first step of getting enough iron while you’re TTC or pregnant is to look at what you’re eating, says Dr. Bestoyong. “Iron is generally found in foods eaten from a well-rounded diet,” she says. 

For meat eaters, iron is abundant in foods like chicken, beef, eggs, and shrimp. The heme iron you get from meat sources is easier for your body to absorb

You can also find iron (the non-heme variety) in plant foods like spinach, white beans, lentils, beets, swiss chard, and soybeans. This type of iron is less easily absorbed by your body, so you might need to eat more of these foods to meet your quota. (Check out this handy chart, which provides how much iron per serving of a bunch of different kinds of foods.) The ACOG also recommends eating foods that help your body absorb iron, like vitamin C-rich citrus fruits, strawberries, and bell peppers.

That said, because iron is particularly important during pregnancy, many OB/GYNs recommend that people take a prenatal vitamin that contains iron. “Prenatal vitamins usually have adequate [iron] supplementation levels for pregnancy,” says Dr. Bestoyong. But if you have anemia, your doctor will likely prescribe a higher-dose iron supplement to help restore your iron levels to a healthy level. 

Are there any side effects to taking iron? 

Be the expert in you.

Take the Quiz

There’s one big bummer about iron supplements: they’re pretty notorious for causing nausea and other stomach issues (think cramps, constipation, or diarrhea). If you’re pregnant and already dealing with morning sickness…that might get worse with an iron supplement. “If someone is taking it on an empty stomach — i.e. Someone who cannot keep down food due to nausea and vomiting early in pregnancy — it can cause more stomach upset,” confirms Dr. Bestoyong. 

But as we’ve already established, iron is pretty important, especially during pregnancy. If you and your doctor still feel strongly about keeping it in your prenatal routine, there are a few things you can do to minimize any unwanted side effects. Take it with a little food rather than on an empty stomach, Dr. Bestoyong recommends. You can also ask your doctor if you can switch to a different form of iron, like ACCRUFeR (an FDA-approved oral iron treatment), to see if that helps. 

Dr. Bestoyong adds that if you’re dealing with nausea and vomiting, you should talk to your doctor to address that underlying issue first before messing with your iron supplementation. 

How to optimize your iron supplementation

There are some other things you can do to get the most out of your iron supplement with minimal puke-y side effects: 

  • Take it with vitamin C: Dr. Bestoyong recommends taking your iron supplement with vitamin C (like orange juice) to help increase its absorption. 

  • Space it out from any dairy or calcium supplements: Calcium can make it harder for your body to absorb iron (rude). Take your iron supplements two hours before or after you have dairy or take a calcium supplement; the same goes if you take antacids for heartburn or stomach upset. 

  • Hold off on fiber or coffee: Similarly, you should not eat super fibery food or drink coffee or caffeinated beverages at the same time as taking your iron supplement. 

The bottom line: Iron is a crucial mineral, particularly when you’re pregnant and trying to conceive, that supports your overall health. If you struggle to get enough of it from food, taking supplemental iron (even if it’s just in your prenatal) can really help you get what you need.

Jessie Van Amburg is a health writer, reporter, and editor with 10 years of experience creating meaningful, compelling journalism in print and digital formats. Her work has been featured in TIME, Women's Health, Well+Good, and more.