By mass, iron is the most common element on earth. We wouldn’t be alive without iron, which is why it is called an essential mineral. Iron is essential for anyone, but it is critical during pregnancy. Iron is a component of hemoglobin, a substance in your red blood cells that carries oxygen from your lungs throughout your body. During pregnancy, your blood volume increases by 50%, which requires a lot of iron. When you are not replacing iron as quickly as your body is using it, you have a deficiency. If you are deficient in iron during pregnancy, it can cause premature labor or your baby to have a low birth weight and impaired cognitive and behavioral development. You can expect to have blood tests that look at your complete blood count, which can tell you if your iron levels are low or potentially anemic. If you are not getting enough iron from your diet, your doctor or midwife may recommend an iron supplement. Deciding what form of iron is the right one to take to maximize your iron levels and minimize unpleasant side effects can be challenging. This episode breaks down the evidence on iron during pregnancy and the different sources of iron, so you can make sure you and your baby have optimal iron levels.