Question: How do I know if my 6-month-old baby is getting enough iron? She is mainly breastfed with one formula feed at night, and we started introducing solids recently. However, she isn’t eating a lot yet. Do I need to introduce an iron supplement? I take an iron supplement; does that increase the amount of iron in my breast milk?
It is encouraging to see that you are thinking about iron! It is an essential nutrient to prioritise at this age. Iron is vital in infants' and toddlers' healthy growth and development. However, it can be somewhat confusing and stressful to know if your baby is getting enough iron, which we don’t want parents to experience around feeding, so I will discuss iron requirements, recommendations on iron supplements, and how to optimise iron intake from the diet.
Your Baby’s Iron Stores
Babies accumulate iron in the womb, and healthy, full-term infants store enough until they are about 4-6 months old. After this period, their iron stores become depleted, and they need iron from their diet. Infant formula milk contains more than double the amount of iron than human milk. There are variations in iron concentrations in the stages and timing of breastfeeding, but unfortunately, it is not influenced by maternal iron intake. Although iron absorption from human milk is estimated to be higher than from infant formula, human milk is still not considered an adequate iron source* (human milk contains, on average, 0.3 mg/L).
*Note this does not imply that human milk is inferior and needs to be replaced by infant formula milk. Instead, it provides important information about when infants should start eating solid foods and why experts recommend introducing solids, especially those containing iron, around 6 months.
Why Is Iron So Important For Infants?
Iron is vital for forming haemoglobin, which transports oxygen in the blood, and for overall growth and cognitive development. Requirements are higher in infancy and childhood, particularly during rapid growth in early childhood (6 to 24 months) and teenage years.
Inadequate iron intake can lead to iron deficiency anaemia, characterised by fatigue, weakness, and impaired motor and cognitive function, some of which are sadly irreversible.
And so, preventing iron deficiency during infancy and toddlerhood is paramount.
How Much Iron Do Babies Need?
Be prepared; the number I will share with you won’t make practical sense.
For a 7-11-month-old baby, the RDA is 11 mg of iron a day.
That is more iron than an adult male needs in a day (8mg/day). To clarify, a formula-fed baby would need to eat ±200g of beef a day, or almost 2 cups of lentils, to meet the RDA, and even more if they were breastfed. I don't know about you, but I have yet seen an infant manage that.
However, it starts making more sense once you understand how the recommended intake is determined and what assumptions have been made.
So, how was the Recommended Intake for Iron Determined?
In Europe, the Dietary Reference Value (DRV) is similar to the US RDA (Recommended Dietary Allowance)* and calculates that the amount of absorbed iron infants aged 7-12 months need daily is 0.79 mg. Studies have shown that this is the amount of iron essential to replace daily iron losses and increase red blood cell mass, tissue iron, and storage iron. They applied a "coefficient of variation" of 20% to account for individual differences in iron requirements, bringing the daily recommended amount of absorbable iron to about 1.1 mg/day.
So then, how do we go from 1.1mg to the RDA of 11 mg for infants? The answer is bioavailability. Based on calculations, it is assumed that in adults, on average, 10% of ingested iron is absorbed by the body because most people in the world get their iron from plant foods (more on that later). So, to meet the biological requirement of 1.1 mg of iron, infants need to consume 10x that amount.
Therefore, the recommended amount of iron for infants is determined using several calculations based on some educated assumptions. There is still a lot we don't know about iron absorption, particularly regarding breast milk and early solid foods. In addition, a person's iron stores can affect how much iron is absorbed from food. Since the body cannot easily get rid of excess iron, it needs to regulate how much it enters the body. Those with lower iron stores tend to absorb more iron, while those with optimal levels absorb less. Other nutrients in the diet also enhance or inhibit absorption, which we will cover in a later section.
*The Recommended Dietary Allowance (RDA) is a measure set at an amount that is two standard deviations above the average requirement estimate (EAR). The EAR is the amount needed to cover the needs of half of the population. The RDA is designed to provide enough of the nutrient in question to meet the needs of 97-98% of the population.
Does my Baby Need an Iron Supplement?
Once you realise your baby is unlikely to meet the recommended amount of iron through food, the next question is if they need a supplement. After all, iron is one of the essential nutrients in your baby's diet. We do want to be making sure they are not developing a deficiency.
First and foremost, the answer is “it depends”.
Although some groups have called for blanket recommendation of iron supplements for all breast-fed infants, many experts have opposed this. Recommendations often depend on the dietary trends and prevalence of iron deficiency within a population. Too much iron isn't a good thing either. Therefore, I recommend always talking to your trusted healthcare provider before supplementing any nutrient, especially iron.
Here are the current general recommendations:
If your baby has an increased risk of iron deficiency (like being born prematurely or having a low birth weight of <2.5kg), your health provider might recommend an iron supplement and advise you on the appropriate dosage and type.
For full-term, healthy babies getting >50% of their milk from human milk, the recommendation is generally to focus on iron-rich foods and screen for an iron deficiency around 9-12 months (see below).
If your baby drinks mostly iron-fortified formula, the answer will most likely be that they do not need additional iron supplementation.
The only way to know your baby's iron stores is to test them. Considering we still have much to learn about iron absorption, getting a blood test before supplementing is always first prize, with a blood ferritin test being the most useful. Some doctors (especially in the USA) offer a quick in-office heel prick test for haemoglobin levels between 9-12 months. If a blood test is not possible or you are worried about your child’s iron status, talk to your healthcare provider about your options and start incorporating the guidelines below.
How to Help Your Baby Meet Their Iron Needs
Even though I have shared some numbers with you, it is important to avoid getting caught up with it and focus on how much food and iron-containing foods your baby consumes. Anxiety around the quantity your baby eats can create an unhelpful cycle of worry and negatively affect your child’s intake.
Instead, all you need to remember is that iron is an essential nutrient and one of the main reasons we start to introduce solids; therefore, you need to focus on the following strategies:
Tip 1: Include an Iron-Rich Food in Every Meal
First and foremost, every meal starting now, or when your baby starts solid foods if they haven't already, should contain an iron-rich food. And yes - I would much rather you prioritise an iron-rich food over a fruit or vegetable. Below are some great sources of iron-rich foods, including whether you are doing baby-led or traditional weaning.
Tip 2: Offer A Variety of Iron Sources
Not all iron sources are created equally. Food contains two types of iron: heme iron and non-heme iron. Heme iron is found in animal sources, is more readily absorbable by our bodies (15-35%), and is not so easily influenced by other dietary factors. Animal meat also increases the absorption of the second type of iron, non-heme iron. Plant sources of foods only contain non-heme iron, which can't be absorbed by the body as easily (only 2-20%). However, this is still an important source and is where most people worldwide obtain iron.
By offering your baby both heme and non-heme iron, you can help increase the amount of iron their body absorbs. But what do you do if your family is vegetarian? Or does your baby have no interest in meat? Still, focus on an iron-rich plant-based food at every meal. And pay attention to the next couple of tips!
Tip 3: Pair Iron-Rich Foods with Vitamin C-Rich Foods
Vitamin C-rich foods are like a magic potion for iron. They single-handedly can help increase iron absorption by 3-6 times, both in heme and non-heme iron sources. Furthermore, vitamin C increases iron absorption from foods more than other foods that inhibit it. It's a fantastic help for iron absorption!
Tip 4: Keep an eye on the total amount of dairy
Calcium has been shown to reduce iron absorption, but the exact mechanisms are unclear. This concern becomes more relevant once your toddler starts consuming milk from sources other than human milk or infant formula (> 1 year olds). Babies are less affected by this since they don't drink cow's milk yet, and their primary source of all other nutrients remains human or infant formula milk.
If your baby's diet contains an excessive amount of calcium and dairy, then it is likely to have an impact on iron absorption over the day. However, instead of focusing on what is being served together at individual meals, it is recommended to offer a variety of foods and include vitamin C-rich foods during mealtimes whenever possible. For toddlers (>1 year), limit cow’s milk to not more than 500ml a day.
Tip 5: Cook Food in Cast Iron Pans or use 'Iron Fish'
Cooking food in a cast iron pan increases iron amounts in foods. Cast iron cookware isn't magic, though. You still need to focus on offering iron-rich foods to your baby, but every little bit can help.
Recently, the use of iron fish has become more prevalent. They are made of food-safe iron powder; most brands shape them into fish, hence the name. When added to cooking liquids (like soup, broths, curries, and stews) with a little acidity, they release non-heme iron into the food the body can absorb when eaten. The fish is reusable and can last a family ± 5 years. Remember to pair it with vitamin C-rich foods to improve absorption (see tips 2 and 3).
What are the Best Food Sources of Iron for Babies?
With all that out of the way, let's get to some iron-rich foods recommendations.
Fortified infant cereal has always been popular when solid foods are introduced to babies through conventional weaning approaches. However, rice cereal, which was traditionally recommended, may contain high levels of harmful metals like arsenic. Therefore, I recommend an iron-fortified oat-based cereal (with no added sugar or salt). Besides cereal, many foods I mention below can be pureed and served to your baby.
Regarding baby-led weaning, many examples of finger food can be iron-rich. If your family eats meat, red meat like beef (ground beef or steak) or lamb can be one of the best options. The heme iron in red meat is easily absorbed and can help your baby meet their iron needs. Iron-rich plant-based foods suitable for baby-led weaning include legumes such as lentils, white beans, firm tofu, spinach, and tempeh. Even iron-fortified cereal can be served with a pre-loaded spoon for self-feeding or used as a base for homemade teething biscuits or pancakes for self-feeding.
Iron-rich Foods to Watch Out For
Many people are proponents of offering babies chicken liver to help their iron intake. I used to be, too. While chicken liver, or any liver, is a good source of iron, it also comes with some risks. Liver meat has a lot of vitamin A and can quickly lead to vitamin A toxicity if too much is eaten. As an organ, the liver detoxifies the body in humans and animals. Any environmental toxin, like heavy metals, gets processed and concentrated in the liver. More recent studies have shown that livers can contain excessive amounts of environmental toxins that far exceed the recommended consumption amount for humans, especially babies. Focusing on other iron-rich foods is better than aiming to serve liver often.
The only other risk to consider is choking hazards, and certain iron sources should be modified to be safe for babies. For example, stir peanut butter into warm porridge instead of serving it on a spoon. Mash beans lightly with a fork or cook/soak dried fruits like apricots before serving them to a baby.
Vitamin C- Rich Foods for Babies
While most fruits and some vegetables are not good sources of iron, they tend to be great sources of Vitamin C.
Here are some examples:
Strawberries
Mango
Orange
Pawpaw
Red Bell Pepper
Chinese spinach
Broccoli
Iron-Rich Foods for Babies
Below, find some examples of iron-rich foods for babies, including how much each serving size offers. Remember, though, it's not about the numbers and how much your baby eats! I include the amounts of iron offered to help you understand how much or how little iron is present in each food and how many different foods can add up.
Animal Sources of Iron
Minced/ground beef (1 tbsp): 0.4 mg
Minced/ground lamb (1 tbsp): 0.3 mg
Chicken (1 tbsp): 0.2 mg
Tuna (1 tbsp): 0.2 mg
Egg*, 1/3rd of a hard-boiled egg: 0.3 mg
Vegetarian Sources of Iron
Iron-fortified cereal (2 tbsp): 3.1mg
Spinach (1 cup raw; 30g): 0.8mg
White beans (1 tbsp): 0.5 mg
Oats (1/4 cup): 0.5 mg
Tomato paste (1 tbsp): 0.45 mg
Lentils (1 tbsp): 0.4 mg
Cooked tempeh (1 slice) 0.41mg
Firm tofu (1 finger): 0.37 mg
Edamame beans (1 tbsp): 0.34 mg
Chia seeds (1 tsp): 0.37mg
Peanuts (serve as peanut butter) (1 tbsp): 0.21 mg
*Eggs are confusing regarding their iron content. While they contain non-heme iron, some research shows they can generally inhibit iron absorption. I believe they can contribute some iron to your baby's diet. However, it's important not to rely on eggs as the primary source of iron for your baby's diet.
Examples of baby-friendly meals:
Red lentil flour penne pasta served with tomato and roasted red pepper sauce.
Fine oats porridge mixed with raspberries and a sprinkle of chia seeds.
Edamame bean fritters (blended) served with sliced mango.
Pureed lamb and sweet potato. Serve with steamed or pureed broccoli.
Tofu slices served with Chinese spinach soup.
Sourdough toast (cut into strips) spread with white bean dip and sliced papaya.
Conclusion
Ensuring your baby receives adequate iron intake is vital for their overall health and development. You can effectively support your baby's iron needs by prioritising serving iron-rich foods at meals, offering dietary variety, and considering factors like vitamin C absorption enhancers. Remember to consult your healthcare provider or dietitian-nutritionist for personalised guidance and monitoring of your baby's iron status. With careful attention to dietary strategies and supplementation when necessary, you can help your baby thrive.
References:
Scientific Opinion on Dietary Reference Values for iron. 2015. EFSA Journal, 13(10), 4254. https://doi.org/10.2903/j.efsa.2015.4254
Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. 9, Iron. Available from: https://www.ncbi.nlm.nih.gov/books/NBK222309/
Ali HS, Almashhadany DA, Khalid HS. Determination of heavy metals and selenium content in chicken liver at Erbil city, Iraq. Ital J Food Saf. 2020 Nov 23;9(3):8659. doi: 10.4081/ijfs.2020.8659. PMID: 33282755; PMCID: PMC7706357.
Brittin HC, Nossaman CE. Iron content of food cooked in iron utensils. J Am Diet Assoc. 1986 Jul;86(7):897-901. PMID: 3722654.
Werner ER, Arnold CD, Caswell BL, Iannotti LL, Lutter CK, Maleta KM, Stewart CP. The Effects of 1 Egg per Day on Iron and Anemia Status among Young Malawian Children: A Secondary Analysis of a Randomized Controlled Trial. Curr Dev Nutr. 2022 May 13;6(6):nzac094. doi: 10.1093/cdn/nzac094. PMID: 35755939; PMCID: PMC9213210.
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