Iron-free prenatal vitamins are an option for pregnant women who react poorly to high doses of iron or for those who are already taking iron supplements separately. You should talk to your doctor before starting prenatal vitamins or switching from one type to another to determine the right amount of iron for you.
Prenatal vitamins help fill any gaps in your diet that could affect your baby. Some nutrients in prenatal vitamins, such as folic acid, are so important to normal development that taking prenatal vitamins significantly reduces the chances of your baby having a birth defect. You can get prenatal vitamins over the counter, but if you have any specific health concerns, you might want to ask your doctor for a prescription version that can address your particular needs.
Problems With Iron
For some women, the benefits of a prenatal vitamin come with the drawback of increased nausea or constipation. Iron can sometimes be the cause of these problems, so a woman who has difficulty with gastrointestinal side effects might want to discuss with her doctor whether iron-free prenatal supplements are an option. For other women, low levels of iron necessitate a separate iron supplement, so they might need to take prenatals without any iron to avoid getting too much of this mineral overall.
Few true iron-free prenatal supplements are available. Most prenatals come in a high-iron version with about 60 mg of iron and a low-iron version with 30 to 35 mg of iron. The recommended amount of iron during pregnancy is 27 mg per day, but women who have anemia or low iron levels may need more. Iron requirements during pregnancy are higher than they are for non-pregnant women. Women who take an iron-free prenatal may need to get more iron from dietary sources.
In many women, gastrointestinal side effects may actually be caused by the size of the prenatal supplement, not the specific nutrient content. A May 2008 study in "BMC Pregnancy and Childbirth" found that pregnant women taking a prenatal vitamin with 60mg of iron did not have any significant increase in gastrointestinal side effects compared to women taking one with 35 mg of iron. However, many supplements with high levels of iron are also large in size, so separating your iron dose from your regular prenatal supplement may still be a viable option.