Iron and Breastfeeding

Iron and breastfeeding
The importance of iron

Iron is necessary for proper brain development. A low level of iron is called iron- deficiency or anemia. It can have a permanent negative effect on a child’s brain development. It can also affect the child’s cognitive or mental abilities.

Iron during pregnancy
Your baby will absorb iron from your body while she grows in your uterus. If you have good iron stores in your body, then your baby will be born with plenty of iron for the first six months or longer. It is helpful if the umbilical cord is left to finish pulsing before it is cut. This allows more blood to flow to your baby. More blood means more iron.

Recent research has shown that many pregnant women in Canada have low iron levels. This means they are anemic. Anemia appears to be more common in some populations than others. Consult your healthcare provider if you have questions about your iron levels.

If you are anemic, you will require an iron supplement during pregnancy. You will also be encouraged to eat iron-rich foods. (See the list of iron-rich foods at the end of this sheet.) Taking an iron supplement and eating iron-rich foods will ensure adequate amounts of iron during pregnancy.

Iron supplements
Vitamin C helps in the absorption of iron. It is helpful to take a supplement that contains both iron and vitamin C. On the other hand, calcium and zinc inhibit the absorption of the type of iron in most iron supplements. Avoid taking a prenatal vitamin with calcium/zinc and the iron supplement at the same time. Instead, take each supplement at a different time of day. Both too much iron and too little iron can be harmful to your body. Consult your healthcare provider before taking any supplements during pregnancy.

The impact of anemia (low iron) on milk production
Anemia can cause fatigue and low milk supply. It can even be mistaken for postpartum depression. If you struggle with fatigue or low milk supply, consider asking your healthcare provider to check the iron levels in your body. This is done with a blood test.

Iron in human milk
The levels of iron in human milk are remarkably constant despite variations in maternal diet or the mother’s iron body stores. Your milk contains the perfect amount of iron to complement your baby’s own iron stores while exclusively breastfeeding. There is also enough to tide your child over during the introduction to solid foods. This iron is in a highly bioavailable form. That means that it’s easy for your baby’s body to absorb. Babies can absorb up to 50% of the iron in human milk, as opposed to only 4-10% of the iron in iron-fortified cereal. The lactose and vitamin C in human milk increase iron absorption.

Human milk contains small amounts of iron, but breastfed babies generally are not anemic or iron deficient. The reason is found in the gut microbes. Studies have shown that formula fed babies have higher numbers of iron-stealing bacteria in their guts. This reduces the amount of iron which can be absorbed by these babies. Breastfed babies, on the other hand, have less iron-stealing bacteria and more vitamin C producing bacteria in their guts. Vitamin C increases the absorption of iron.

What about iron supplements for your baby?
Full-term babies who are exclusively breastfed for the first six months generally don’t need iron supplements. However, babies born premature, or exclusively breastfed for less than six months, may have low iron levels. If you are concerned about your baby’s iron levels, speak to your healthcare provider. They can easily be checked with a blood test.

Some babies given iron supplements experience digestive upsets, such as vomiting and diarrhea. These supplements can change the balance of the gut flora. Your milk contains two proteins that bind with iron in your baby’s gut. This prevents harmful iron-loving bacteria from multiplying. When iron supplements are given to a breastfed baby, these proteins are overwhelmed by the extra iron in the baby’s gut. This allows harmful iron-loving bacteria to thrive.

Introducing iron-rich foods
The World Health Organization, Health Canada and Canadian Pediatric Society all recommend that babies be fed human milk only until about the middle of the first year. By about the middle of the first year, the iron your baby got in utero and before the umbilical cord was cut will be almost gone. Babies with larger iron stores can go longer before needing additional iron from their food. Those with smaller stores, such as premature babies or those whose mothers were anemic during pregnancy, may need iron from food sooner.

Once solids are started, babies should eat some foods rich in iron. For most babies these will provide sufficient amounts of iron. Most breastfed babies do not need iron supplements.

It is normal for babies to spend a lot of time exploring and playing with food at first. It can be several weeks, or even several months, before a baby is eating a significant amount of solids. However, some babies eat quite a bit starting on day one. This is understood in the recommendation to begin solids at six months. As the months progress, most babies will work up to taking solids on a regular basis. In the meantime, the iron in your milk will continue to provide your baby with a source of iron that is easily absorbed by your baby’s body.

Foods to introduce
Because human milk is relatively low in protein, foods that are high in protein, iron and zinc, such as red meats, are an appropriate early food for breastfed babies.

La Leche League suggests babies start with ripe banana, avocado, yam or sweet potato to introduce them to different tastes and textures. This also gives them practice with the process of tasting and swallowing. Meat is the next recommended food because of its high content of protein and iron. (The form of iron in meat is especially bioavailable.) Vegetarian families would want to offer non-meat iron-rich protein foods. (See list below.) After that come whole grain breads and cereals.

(Note that because formula is much higher in protein than human milk, low protein foods such as iron fortified cereals may be better first foods for formula-fed babies. This prevents formula-fed babies from getting too much protein which can put stress on a formula-fed baby’s kidneys.)

The following iron-rich foods can be introduced around six months:

  • Dark green and bright orange fruits and vegetables, such as: spinach, broccoli, green peas, kale, sweet potatoes, yams, winter squash
  • Meat and poultry
  • Egg yolks
  • Seafood (ideally, low and no mercury options)
  • Whole grain breads and whole grain and enriched pasta
  • Whole grain cereals such as brown rice, oats and barley
  • Tofu
  • Lentils, dried peas, soy beans, hummus
  • Seeds: pumpkin, sesame, sunflower, tahini Nuts, including peanuts
  • Molasses, prune juice and tomato juice

Alberta Health Services, Nutrition Services. (2021). Iron Foods for Pregnancy.

Kelsey M Cochrane, Jennifer A Hutcheon, Crystal D Karakochuk. (October 2022). Iron-Deficiency Prevalence and Supplementation Practices Among Pregnant Women: A Secondary Data Analysis From a Clinical Trial in Vancouver, Canada. The Journal of Nutrition, 152(10), 2238–2244.

Mohrbacher, Nancy. (2020). Breastfeeding Answers: A Guide for Helping Families, Second Edition. Nancy Mohrbacher Solutions, Inc; pg 143-144.

Health Canada. Nutrition for healthy term infants: Recommendations from birth to six months. (July 2022).

Tahir, E., Ayotte, P., Little, M., Bélanger, R. E., Lucas, M., Mergler, D., Laouan Sidi, E. A., Community of Winneway - Long Point First Nation, Community of Lac Simon, CSSS Tshukuminu Kanani of Nutashkuan, Community of Unamen Shipu, McHugh, N. G., & Lemire, M. (2020). Anemia, iron status, and associated protective and risk factors among children and adolescents aged 3 to 19 years old from four First Nations communities in Quebec. Canadian Journal of Public Health, 111(5), 682–693.

Updated 2023