Iron in Breast Milk

Breast milk is a complete food containing everything a baby needs for around the first six months of life, including iron. Although levels of iron in breast milk aren’t high, a baby is also born with iron stores (extra iron stored in the blood). Breast milk will normally have the perfect amount of iron to complement these stores until a baby starts eating solid food.

Does my baby have enough iron?

Most babies are born with iron stores sufficient to last around six months1, which is when they will normally start to eat iron rich table foods2. However there are some situations when a baby’s iron stores may be low.

When might a baby’s iron stores be low?

If mother is anaemic during pregnancy

Georgieff (2009) says that if a mother is anaemic during pregnancy it is a primary risk factor for restricting the amount of iron available to the unborn baby. Georgieff also links maternal hypertension, diabetes or if she smoked during pregnancy with a baby’s low iron status3. Iron deficiency in pregnancy can increase the risk of a baby having a low birth weight or being premature in addition to increasing the possibility that a baby may have low iron stores4. If a mother is anaemic after birth this can be associated with tiredness, low milk supply and postnatal depression (OUH, 2017).

Premature birth/low birth weight

If a baby was born prematurely they may not have had enough time to get iron from their mother during the last few weeks of pregnancy5. Babies with a low birth weight might be at risk of low iron stores.

Cutting the umbilical cord early

If baby’s umbilical cord was cut before it stopped pulsating they may not have received the full complement of iron and blood supply. The Womanly Art of Breastfeeding states:

If your baby’s cord was cut before it stopped pulsating, he missed out on up to a third of his intended blood supply. That’s a lot of iron to lose. he should be find for the first half year, and will probably be fine from then on as well, but when he starts solids look for iron-rich foods such as meats, dark green leafy vegetables, and beets (much better than the type of iron in baby cereal).

See Rachel Reed’s The Placenta: essential resuscitation equipment, 2018 for more reading.

Early solids

If your baby started solid foods very early; some fruits and vegetables can bind with the iron in your milk before your baby has a chance to absorb it and iron stores may drop (Womanly Art, 2010). Iron stores may also be low in babies who are given cows’ milk to drink during their first year.

Absence of iron rich food

Breastfed babies who don’t have any iron rich foods after six months of age may also have low iron stores.

Health reasons

Babies with certain health conditions may have low iron stores.

Iron in formula

One reason why iron levels in breast milk are sometimes said to be “low” may be due to industrial promotion of the “higher” iron levels in infant formula since the 1980s. The iron supplements added to formula milk are much harder for a baby to absorb and consequently more iron has to be added to compensate. Babies can absorb 50% of the iron in breast milk, compared with only 2-9% of the iron in artificial milk and 4% from fortified baby cereals6. Lactose, the main sugar in breast milk assists iron absorption along with vitamin C.

The high iron content in formula is not “better” than the normal amount in breast milk despite clever marketing giving that impression. In fact too much iron may increase the risk of illness 78.

Too much of a good thing

Too much iron may cause:

  • Higher rates of infection. Breast milk contains a protein called lactoferrin that binds to any extra iron that your baby doesn’t use. This keeps harmful intestinal bacteria in check because otherwise they thrive and multiply if there is excess iron. If this system is overloaded by iron supplements, the harmful bacteria thrive, potentially leading to higher infection rates, diarrhoea and even microscopic bleeding9
  • Constipation. Too much iron can lead to constipation10.
  • Colic. Iron supplements can affect some babies and cause colic type symptoms 11.
  • Changes in growth and micronutrient status. Some studies show decreased growth, decreased absorption of zinc and changed vitamin A metabolism if iron supplements are provided when not needed 12.

Babies need iron

Although it is not good for a baby to have too much iron, it is nevertheless very important that they have enough. Symptoms of low iron can include slow weight gain, pale skin, no appetite and irritability (fussy behaviour) 13.

Iron deficiency is said to be the most common nutrient disorder across the world. A deficiency in iron can lead to developmental delays and neurological problems which may not be reversible when treated.14.

Although most breastfed babies will have sufficient iron from their iron stores and breast milk, if there is any doubt a blood test will confirm your baby’s iron status.

Can I increase the iron in breast milk by taking supplements?

No, a mother can’t increase the iron levels in her breast milk by eating iron rich foods or taking supplements 15.

Can drinking coffee reduce the iron levels in breast milk?

Possibly, several references online connect drinking a lot of coffee with less iron in breast milk. The volume of coffee that might effect iron levels in breast milk varies between authors for example from 450ml 16 to 1 litre 17 per day.

Three cups of coffee or more per day may be associated with a reduction in iron content of breast milk of up to one third of that of women who don’t consume coffee. Moreira (2005)18 noted the iron-reducing activity of coffee beverages was not influenced by caffeine, but rather by the presence of chlorogenic acids in coffee. Chronic coffee consumption by the mother could result in iron deficiency anaemia in the breastfed infant (Liston, 1998)19.

See Coffee, Caffeine and Breastfeeding for more information.

Routine iron supplements not needed

In 2010 the American Academy of Pediatrics issued guidance recommending that exclusively breastfed term infants have iron supplements from four months of age. This was strongly countered in a Letter to the Editor by a number of medical professionals (Landers, S. et al.) who were concerned that the recommendations didn’t address the potential harm of iron supplementation or the difference in how easily the iron in human milk is absorbed compared with iron-fortified fluids and foods.

The current guidance from the Amercian Academy of Pediatrics does not recommend routine iron supplements in healthy breastfed babies:

Most babies are born with sufficient reserves of iron that will protect them from anemia. If your baby is breastfed, there is sufficient, well-absorbed iron to give her an adequate supply so that no additional supplement is necessary. When she is about six months old, you should be starting your breastfed infant on baby foods that contain supplemental iron (cereals, meats, green vegetables), which should further guarantee sufficient iron for proper growth. When you add solid foods to your baby’s diet, continue breastfeeding until at least 12 months. Check with your child’s doctor about vitamin D and iron supplements during the first year.

Summary

Breast milk normally contains the perfect amount of iron to complement a baby’s iron stores until they start eating solid food. There are a few situations where a baby’s iron stores may be low such as if the mother was anaemic during pregnancy or if a baby was born prematurely. Babies need sufficient iron for healthy growth but too much iron also has negative health consequences. Consult with your health professional if you have any concerns about yours or your baby’s iron status.