Estimated reading time: 5 minutes
Katja Leccisi, MS, RDN, Mont-Tremblant, Quebec, Canada
Photo: Anna Bondarieva
Eating well during pregnancy and iron requirements.
Good nutrition means eating a well-balanced and varied diet of foods in as close to their natural state as possible.
Many of the pregnant women I see have questions about how much iron they should be getting from their diet. Why the fuss about iron? Basically, because a lack of iron during pregnancy can have some unpleasant effects: weakness, fatigue, and lower resistance to infection. If the lack of iron is persistent and more severe, the situation can turn into a case of iron deficiency anemia, which might increase the risk of premature delivery or low birth weight.
First, let’s be sure we understand what is happening during pregnancy with regards to iron. This is the clearest simple description I have found, from the Mayo Clinic:
“Your body uses iron to make hemoglobin, a protein in the red blood cells that carries oxygen to your tissues. During pregnancy, your blood volume expands to accommodate changes in your body and help your baby make his or her entire blood supply—doubling your need for iron. If you don’t have enough iron stores or get enough iron during pregnancy, you could develop iron deficiency anemia.”
Your baby will also store iron during the third trimester, so that he has adequate amounts to carry him through until he starts eating complementary foods at about six months of age. Your health care practitioner will most likely do blood tests to check your hemoglobin levels. It is fairly common for iron levels to fall slightly during the third trimester. Normal levels are in the range of 12–15g/dL. If they drop below this, additional blood tests may be needed to look at the iron in your blood and your iron stores.
How much iron do you need?
Women aged 19–50 need 18mg/day of iron. During pregnancy, the recommended daily allowance for iron jumps up to 27mg. Maternal anemia restricts the amount of iron available to the unborn baby (1Most pregnant women have a hard time getting all the iron they need through food only, so most public health organizations (such as Health Canada and the American College of Obstetricians and Gynecologists) recommend a daily prenatal supplement that contains at least 16–20mg of iron. Some women find that iron in a prenatal supplement contributes to constipation and that liquid iron supplements are less constipating because the daily requirement can be divided into a few daily doses.
What are the best ways to get dietary iron?
Eat plenty of iron-rich foods every day, and do your best to enhance the absorption of the iron. There are many foods that contain iron, either naturally or because the food has been fortified. See a comprehensive list with amounts from the Dietitians of Canada. Examples of fortified foods are breakfast cereal, pasta, and flour. Iron is also found in different forms: heme and non-heme. Heme iron is only found in animal foods (meat, fish, poultry), while non-heme is the form of iron in plant-based foods (although there is also some in animal foods). Some good vegetarian sources of iron include: beans, peas, lentils, tofu and soybeans, most nuts and seeds, molasses, and dried fruits such as dates and apricots.
Iron absorption is somewhat complicated. In general, the heme form of iron is more easily absorbed by our bodies. But many factors are involved. The most important is the presence of vitamin C at the same meal. By including a source of vitamin C, especially when eating non-heme (vegetarian) forms of iron, you will maximize your absorption of iron. Some examples of good sources of vitamin C are: broccoli, cantaloupe, citrus fruits and their juices, kiwi, mango, potatoes, strawberries, bell peppers, tomatoes and their juice and sauce. Cooking in a cast-iron dish has also been shown to be beneficial. Be aware that some factors can inhibit the optimal absorption of iron, although the extent to which they do this is still under debate. To err on the side of caution, avoid drinking tea or coffee with meals. It is also suggested that you don’t take your prenatal supplement with your meals, because calcium-containing foods may inhibit iron absorption. Of course, there is the practical side to this, especially if you are dealing with nausea during pregnancy: take your supplement whenever you best tolerate it.
Most breastfed babies will have sufficient stores of iron until the middle of the first year. Babies absorb iron more readily from mother’s milk than from artificial milk (60% compared with only 4%). Eating iron rich foods or taking supplements will not increase the iron level in your milk. (2) A simple blood test can reassure you of your baby’s iron status. Mothers who breastfeed their babies usually do not resume their menstrual cycle for at least a few months (often much longer), conserving the iron that would otherwise be lost every month.
An iron-rich recipe
Kale, cashews, and sesame seeds are all good sources of iron. And here’s a colorful salad recipe for Gingery Thai Kale Salad from the Minimalist Baker that you can vary to suit individual tastes.
- 1 cup (100 g) green beans, stems removed, steamed and chopped
- 1 tsp tamari (or soy sauce if not gluten free)
- 1/2 tsp sesame oil
- 1 tsp maple syrup
- optional: 1 tsp sesame seeds
- 2 tsp sesame oil (or grape seed oil)
- 2 shallots, thinly sliced
- 2 bundles (402 g) lacinato (non curly) kale, torn into bite-size pieces, large stalks removed
- 3 whole carrots (180 g), chopped or ribboned
- 1/2 red bell pepper (60 g), quartered and thinly sliced
- optional: 1/4 cup (15 g) fresh chopped cilantro or basil
- 1/3 cup (40 g) roasted salted cashews (or substitute peanuts)
- 1/3 cup (85 g) salted cashew butter (or substitute peanut butter)
- 1 Tbsp (15 ml) tamari (or soy sauce, if not gluten free)
- 2 tsp fresh grated (or very finely minced) ginger
- 1/4 cup (60 ml) fresh lime juice
- 1 Tbsp (15 ml) maple syrup
- 1 Tbsp (15 ml) sesame oil
- optional: 1 tsp chili garlic sauce or 1/4 tsp red pepper flake
See here for the full instructions.
More from Katja: Eating Well during Pregnancy: Coping with Morning Sickness Nausea, Eating Well during Pregnancy: Weight Gain, Food Themes in Children’s Books, How To Feed Your Kids / Cómo alimentar a tus hijos, Let Your Child Eat! / Lass dein Kind essen! My First LLL Meeting and a Cookie Recipe, Raising Healthy Eaters: Lessons Learned from Breastfeeding
Find what you want to read: article index
- Georgieff, M. The role of iron in neurodevelopment: fetal iron deficiency and the developing hippocampus. Biochem Soc Trans. 2008;
- Lauwers, J., and Swisher, A. Counseling the Nursing Mother: A Lactation Consultant’s Guide 5th Edition, London: Jones & Bartlett; 2011.