Should Human Milk Be Fortified For a Premature Baby?

Attempts to fortify human milk for preemies are very common…  …It all sounds great, but there are many problems associated with fortification.

Newest related post:  Fortify Human Milk for Premature Infants?

See Also:  What You Need to Know Now About Feeding A Premature Baby

and Preemie Feeding: Human Milk Fortifier? Donor Milk?
for more information on feeding preemies.

Below is excerpted from “BABY MATTERS.” Even more up-to-date information on the question of fortifying premature infants’ mother’s milk is available in “BABY POOP.”

Attempts to fortify human milk for preemies are very common. Calcium and phosphorous are often added in attept to improve early bone mineralization. Protein is added in an attempt to increase growth rate. Other vitamins and minerals are often added as well. It all sounds great, but there are many problems associated with fortification.

One study analyzed the feeding of a high-protein formula that contained
3 times the protein of human milk, comparing this feed to mother’s milk in low-weight babies. The growth rates were similar, but the high-protein infants had high levels of toxins from protein breakdown in their blood (urea and creatinine). Additionally, two amino acids (components of protein), phenylalanine and tyrosine, were found to be too high in the formula-fed infants’ blood. In excessive amounts, these hinder nervous system development.

Another study reviewed protein utilization in a formula with extra cow’s milk protein added, compared with human milk with extra human milk protein added. The human protein fortified infants gained more weight and had better protein balance. A more recent examination of nonhuman protein enrichment of mother’s milk found more severe illnesses and a reduced duration of “full” breastfeeding while a greater duration of full breastfeeding was associated with better growth scores.

Most breastmilk fortification contains cow’s milk proteins. These are not desirable with breastmilk or in preemie formulas (although they are in nearly all formulas). A few of the problems with these dairy proteins are the high incidence of bovine protein intolerance associated with intestinal inflammation, bleeding, and diarrhea; the slow breakdown of these large proteins in the tiny system, preventing additional formula feedings as early as they are needed for proper caloric intake; and the increased risk of developing childhood diabetes — the risk being greater the earlier cow’s milk proteins are introduced (all of these topics are addressed elsewhere in the book).

It has been shown that breastmilk fortified with any cow’s milk products, which includes nearly any preemie or infant formula or milk fortification powder, reduces the immune protective properties of mother’s milk. A higher rate of infection is seen in infants fed fortified breastmilk versus those fed only human milk. The immune protection from mother can be reduced by fortification in part because E. coli bacterial growth in the intestine increases, which mother’s milk alone hinders. This bacterial flora sets the stage for many diarrheal illnesses. Non-iron-containing soy derived products do not promote E. coli and lead to a lesser increase in infection
overall; however, soy can also cause allergic intolerance.

Various researchers are interested in supplementing elements such as sodium, phosphorous, calcium, and vitamins to the breastfed preemie. These can all be provided without dairy products or iron. Iron supplements will feed E. coli and other challenging bacteria, blocking much of breastmilk’s infection protection, and is not needed in most cases. Vitamins shouldn’t be harmful in low quantities according to the research to date, and vitamin D may enhance bone building when neither mother nor infant is obtaining much sun exposure.

In a German study, half of the preterm infants receiving medium or high levels of calcium supplementation were found to have dangerous calcification in their kidneys, and many suffered abdominal distension as well. We have already seen that breastfed preemies eventually show very good bone mineralization with no supplementation. Another study suggests that bone mineralization in breastfed preemies is as high as in formula-fed preemies by just a few months after birth, but the concern continues about the light bone mineral content early on for breastfed low-birthweight infants.

While it seems a little backwards to use formula-fed infants as the gold standard, comparisons to intrauterine growth are used as well. Breastfed preemies’ bones may lag behind formulafed preemies in this arena. While a very low level of calcium and phosphorous supplementation to the breastfed preemie does not appear harmful, the latest review of studies is unable to confirm an advantage. Added vitamin D may help these to be absorbed.

If protein fortification is desired, it should come from a human or possibly
soy source. Much more research is needed in this area. Vitamin fortifications
appear to have little downside, as opposed to minerals, proteins, or
other components.

© Linda Folden Palmer

For Linda Palmer’s most recent and complete information on feeding premature infants and the questions about fortifications, see her most recent book:  BUY "BABY POOP"


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  • Inga Teller May 20, 2014 at 4:53 am

    Dear Linda, it would be great if the referenes would be integrated in the text. It is also noteworthy that the references in the list below are totally outdated without a single reference to current scientific knowledge. It would also be great if you could explain why medical associations such as ESPGHAN recommend human milk fortification for preterm infants if that was so unnecesary as you state in your book. Third, please update your product information as there are several products for premature infants on the maket to fortify human milk with hydrolysed protein. These may also contain minimal concentrations of iron. Just check the current lables, instead of raising concerns that no longer apply. Fourth, please consider that many preterm mothers have a hard time supplying and expressing enough milk for their child. They are under lots of stress and it is really hard to do so when your child is in the hospital and you yourself may not be well, either. the infants then should ideally have access to donor banks. If the donated milk is used to prepare (in my opinion redunantly) human milk fortifier intead of using hydrolysed cow’s milk protein the available/ accessible milk for the preterm child will be reduced. I think it is more important to feed the child the milk instead of channeling it into an industrial path if hydrolysed protein is just fine. And finally, in many current fortifiers and formulas the protein amino acid profile has been adjusted long ago to be more closely to that found in human milk. In short: PLEASE GET YOUR FACTS STRAIGHT. You could start by updating your science knowledge and the references.
    Kind regards,

  • Linda F. Palmer May 20, 2014 at 11:05 am

    Hi Inga, thank you so much for taking the time to write.

    I’d like to give you a much longer reply than I’ll post here, so please write me at Let me answer your topics one at a time. In terms of the references being integrated in the text, in the book, they are, although I doubt I’ll ever do that again in future books. With 1200 science journal references, it was an incredible effort and with pocketbook-breaking editing assistance, where affordable software still does not seem up to the challenge.

    Outdated: This is an excerpt from my 2009 updated version (“The Baby Bond”) of my original 2001 book, “Baby Matters.” You’ll see in this page on my site: that I’ve used articles up to 2009. But, I’m working as we speak on finishing up my newest book, “Baby Poop,” and I’ve put lots of time and effort into this section, covering all of the most recent info I can find, and speaking by phone with a couple of the researchers to answer my questions. I’ve wished for my writing on this topic to spark discussion and hoped to depend upon that “peer review” for my most new coverage of the topic. I wish to send you a copy of this section of “Baby Poop” for your valuable review. I spend my time with research articles and blogged lactation professional comments. I sure could use some insights from someone with boots on the ground.

    I’m curious about your hydrolyzed milk protein comments. We know that they can reduce the very common allergic/intolerance reactions, but certainly not avoid them in all babies. The other main issue is that of interfering with human milk’s immune provisions, which foreign proteins seem to do as much as iron does. I wish there were more research on this, but there’s not, but am I reading you that you think that hydrolyzed proteins would interfere less? This is an interesting idea. Maybe amino acids would/should interfere even less? Wow. I need to ruminate on this one.

    Your comment about preserving available donor milk is thought provoking and I guess the issue largely depends upon availability.

  • Iron Rich Foods for Toddlers February 8, 2015 at 5:02 am

    […] Gradually, as the age of your baby increases, it'd be easier for you to feed him/her with the above fortified baby foods and foods rich in iron mentioned below. Iron intake not more than 7.8mg per day is considered […]


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