Pumping iron isn’t just for the gym. You can — and should — pump it up in your pregnancy diet, too. Iron is essential during pregnancy to support your baby's developing blood supply, as well as your own.

The mineral is so vital for baby's growth, in fact, that your recommended daily intake nearly doubles when you're expecting. Having low iron stores can increase your risk of developing anemia, and severe iron deficiency may lead to low birthweight or premature birth.

With that in mind, is it necessary to take iron supplements when you're pregnant? Here's everything moms-to-be need to know about iron during pregnancy, including how to fill up on iron-rich food sources and how to know if supplementary iron is something you need.

Why is iron important during pregnancy?

It might seem counterintuitive that you need more iron during pregnancy considering 70 percent of iron is found in red blood cells — and you’re no longer losing blood each month during your menstrual cycle

But your iron needs actually jump during pregnancy because your body produces more blood — to deliver oxygen to your growing baby and because you’re growing, too. Iron is also important in fetal brain development. 

Having low iron levels can put you at risk for anemia, especially during the second half of your pregnancy.

How much iron do pregnant women need?

Pregnant women need 27 milligrams of iron per day (compared to 18 milligrams for adult women 19 to 50 years old who are not expecting). 

Most prenatal vitamins include enough iron to cover that increase, but iron-deficiency anemia is common in pregnancy due to the increased demand for blood production. Luckily, it's easy to prevent by filling your plate with plenty of iron-rich foods and, if your practitioner recommends one, with the help of a daily iron supplement.

Best iron-rich foods for pregnant women

The most easily absorbed sources of dietary iron (heme iron) include lean meat, poultry and fish. Non-animal (non-heme) sources are still beneficial, however, and you can enhance their uptake by consuming them alongside vitamin C-rich foods.

Best heme iron-rich food sources

If you're looking to pump up the iron in your diet (and you're not vegetarian or vegan), try adding these iron-filled foods to the menu: 

  • Canned sardines: 2.4 mg per 3 ounces
  • Braised beef: 2 mg per 3 ounces
  • Chicken: 1 mg per 3 ounces
  • Eggs: 1 mg per 1 hard-boiled egg

Best non-heme iron-rich food sources

If you're vegan or vegetarian — or just trying to eat more plant-based foods — these options will get more iron on your plate:

  • Fortified breakfast cereals: 18 mg per serving
  • White beans: 8 mg per cup canned
  • Lentils: 3 mg per ½ cup boiled
  • Spinach: 3 mg per ½ cup boiled
  • Firm tofu: 3 mg per ½ cup 
  • Dark chocolate: 2 mg per ounce
  • Tomatoes: 2 mg per ½ cup canned and stewed
  • Kidney beans: 2 mg per ½ cup canned
  • Cashews: 2 mg in 18 nuts 

Should you take iron supplements during pregnancy?

An iron-containing prenatal vitamin in combination with sufficient dietary sources of iron throughout the day can provide many pregnant women with adequate amounts of the mineral. But iron-deficiency anemia is common, particularly after week 20 of pregnancy, and some moms-to-be do need a daily iron supplement in addition to their prenatal.

A blood test can check your iron levels and determine if you might need to take iron tablets during pregnancy that go beyond what’s supplied in your prenatal. 

Anyone can develop anemia, but vegans and vegetarians have a higher risk, as do women carrying multiples, or those who have had back-to-back pregnancies or severe morning sickness. If you fall into one of those categories and notice symptoms of anemia (such as feeling fatigued, dizzy or breathless), ask your doctor if you might need an iron supplement.

Iron supplements come in various forms and amounts. Because iron can cause nausea and constipation, your practitioner may suggest slow release capsules or a different form of iron (like iron bisglycinate) that's easier on the stomach. 

If your doctor has also recommended supplementary calcium (or there's calcium in your prenatal vitamin), you shouldn't take it at the same time as an iron supplement, since calcium can interfere with iron absorption. Instead, plan on taking these supplements at least two hours apart.

The bottom line: For most women, iron supplementation is safe during pregnancy. However, not every mom-to-be needs extra iron, especially since the mineral is already found in most prenatal vitamins and certain common foods. As always, talk to your practitioner before adding any new supplements to your diet.