How Much Iron Does My Baby Need?
Our Pediatric Registered Dietitian breaks down one of the MOST important nutrients when starting solids.
Starting solids at 6 months has a lot to do with iron.
Before we dive into all the science around iron, it’s important to draw attention to the fact that baby’s iron stores start to deplete around the time baby turns 6 months of age. So, while baby’s motor development is an important piece to consider when starting solids, baby’s iron needs are also a factor. Baby usually meets all of the motor prerequisites to start solids around 6 months of age, and that’s about perfect timing as their iron needs change, too!
What is iron and why is it important?
Iron is a mineral essential for growth, development, and transportation of oxygen throughout the body. It is needed for making hemoglobin and myoglobin which carry oxygen to our tissues and muscles. Not enough iron can result in too little hemoglobin and myoglobin production, which leads to anemia.
Heme vs Non-Heme Iron
There are two types of iron found in foods - heme iron and non-heme iron. Heme iron is found exclusively in animal foods, while non-heme iron is found both in animal and plant foods, but mostly in plant foods. These two types of iron are not equal in quality and bioavailability (more on that later).
Iron Deficiencies and Risk Factors
Iron deficiency is one of the most common nutrient deficiencies in babies and children in the United States.
It is a very serious deficiency that can impact growth, development, sleep, and a child’s overall wellbeing. Iron deficiency anemia is found to be associated with shorter sleep durations in the first year of life (1). Iron deficiency also affects the growth of multiple organ systems, most notably the brain, with the effects being permanent and life-altering (2).
In the United States, pediatricians do routine screening for anemia (low iron) around 12 months of age. There are some risk factors that make anemia more likely in babies, including:
Babies fed non-iron fortified formula
Babies born prematurely (iron stores from mom are transferred to baby at the end of pregnancy)
Babies born with a low birth weight
Babies who are fed cow or goat’s milk before age 1
Babies who start solids after 8 months old
Babies not given iron rich foods after 6 months old (2)
The most important risk factor for iron deficiency anemia in infants is the introduction of cow’s milk within the first year of life. Cow’s milk is low in iron, and the iron that it does contain is poorly absorbed. Also, the high casein and calcium content in cow’s milk decreases the absorption of iron from other dietary sources (3).
This is why cow’s milk offered alone as a drink (e.g., not when added to a recipe or smoothie, for example) is NOT recommended before age 1. Dairy products like cheese and yogurt are safe to offer baby, along with milk used in recipes. But offering cow’s milk alone to baby, especially as a main form of nutrition, should be avoided in the first year of life.
So, how much iron does my baby/toddler actually need?
0-6 months:
Most healthy, full-term babies are born with adequate iron stores for the first 6 months of life. Iron is transferred from mom to baby during the last trimester.
Delayed cord clamping can be very beneficial for baby’s iron status in the first 6 months after birth because it ensures baby is able to get all the cord blood (including all the iron). A study found that the benefits of reduced anemia continued even after 6 months. Delayed cord clamping of greater than 3 minutes resulted in a reduction of anemia by 9% at 8 months and by 8% at 12 months of age (4).
Premature and low birth weight babies may require early iron supplementation due to their higher risk of iron deficiency that comes from their small size, reduced iron stores at birth, and iron losses from blood tests. A plan for supplementation should always be made with your pediatrician.
6-12 months:
The RDA (recommended daily allowance) for iron in babies 6-12 months is 11 mg/day. This is a lot of iron - more than the RDA set for an adult male! To give you an idea of how much this is - 1 oz of ground beef has about 0.5 mg iron, and a typical serving size for a meal for a 6-9 month old is usually no more than 3 ounces (give or take).
So, why is the RDA set to what seems like such an unrealistically high amount? Well, the scientists setting the RDA assumed the average bioavailability (absorption rate) of iron in food to be only around 10%. (5) But, this is true only for plant-based iron sources. Assuming a 10% absorption rate, the RDA was set to aim for 1.1 mg of absorbable iron per day, which is about 11 mg of iron from plant-based (non-heme) sources.
The great news is the heme iron found in animal foods is much more absorbable or bioavailable at an average of 25-40%, compared to the 2-13% (average <5%) absorption rate of non-heme iron foods. So, if for example, a baby is consuming heme iron sources (animal sources), then they would need to consume a lot less total iron to reach the 1.1 mg of absorbable iron per day. If assuming a 25% absorption rate, then only 4.4 mg of heme iron would need to be eaten to reach 1.1 mg of iron absorbed, in contrast to the 11 mg needed with non-heme iron. So, going back to our first example, 3 ounces of ground beef in one meal would have ~1.5 mg of iron out of the 4.4 mg needed, making the total iron needs for the day much more attainable feeling!
In short, iron from animal foods gives you a lot more bang for your buck.
Babies who are being fed an iron-fortified formula will likely meet their iron needs through the formula alone in the first year of life depending on how much they are consuming. But, it is still good to offer iron-rich foods regularly since formula won’t be offered into toddlerhood.
Breastmilk does contain small amounts of iron that is well absorbed by baby, but after 6 months it does not supply enough to meet the demands of rapid growth that happen between 6-12 months.
It is especially important for breastfed babies to receive iron-rich foods regularly when starting solids.
For Toddlers 1-3 Years Of Age:
7 mg of iron per day is recommended, but again, this amount was set with the assumption of a 10% bioavailability rate. If you are offering animal products high in iron, it will be much easier to reach that recommendation!
Iron Fortification is Not Equivalent to Iron-Rich Foods
Many processed foods for babies and children, including a popular pediatrician-recommended first food for baby - rice cereal, are fortified with iron; but, it is best not to rely on these foods to meet iron needs. A better way is to regularly offer foods rich in bioavailable iron once baby starts solids.
The iron found in fortified food is not equal to the iron found naturally in foods.
The iron found in fortified foods is not absorbed well (it is non-heme iron) and can cause gastrointestinal side effects. Also, the iron doesn’t necessarily have all the co-factor nutrients that help the body actually use the iron that is consumed. On the other hand, the heme iron found in animal foods is in a more absorbable form and is naturally packaged with important co-factors that help with utilization of the iron such as specific amino acids, Vitamin A, copper and zinc.
Iron Absorption in Animal Foods vs Plant Foods
As previously mentioned, the heme iron found in animal foods has a higher absorption and utilization rate than the non-heme iron found in plant foods. This information is especially important for families following vegetarian or vegan diets. Remember, knowledge is power!
Generally speaking, the amount of plant-based iron containing foods that you would have to eat in order to match the amount of iron actually absorbed from animal foods is a lot. The charts on this website are very helpful for comparing absorption rates of animal based foods and plant-based foods. For example, “to match the total iron content of 1 oz of clams, you would need ~11 cups broccoli, but to match the iron absorption of 1 oz of clams, you would need ~57 cups of broccoli.” (6)
The reason non-heme iron in plant foods is not well absorbed is that many of these foods contain other compounds that decrease iron absorption, such as fiber, oxalates, phytic acid and tannins (6), whereas heme iron foods contain co-factors that help increase iron absorption.
How to Increase Iron Absorption From Foods
The same compounds that inhibit iron absorption in non-heme sources can also affect heme iron absorption. There are some strategies that can be utilized to boost iron absorption to try and offset this.
Eating foods rich in vitamin C at the same time as iron-rich foods can help increase absorption of iron. A study found that consuming 100 mg of vitamin C with a meal increased non-heme iron absorption by about 3x (7).
Calcium impairs iron absorption, so if trying to maximize iron absorption, serve calcium-rich foods away from iron-rich foods.
Cooking food in cast iron pans can increase the amount of iron in foods because some of the iron from the pan leaches into the food. More acidic foods tend to leach more iron.
As your baby starts eating solid food and growing into a toddler, it is important to maximize their iron intake for their rapidly developing bodies. Overall, the iron concentration and rate of absorption from animal foods is much better than plant foods. Even though your little one can certainly benefit from eating plant foods, the most bang for your buck with iron is going to come from including iron-rich animal foods early and often. If you’re including a good mix of iron-containing animal foods along with plant foods, then there’s no need to stress about it or try and track how much iron your little one is eating. If your family is following a vegetarian or vegan diet, it will be important to be more in tune to how much iron your little one is absorbing, and continuously talk with your pediatrician about regular iron testing or red flags for iron deficiency.
Foods that are High in Iron
Our top favorite animal foods to serve to babies that are high in iron are:
Organ Meats (Beef Liver, Chicken Liver)
Ground Beef
Sardines
Oysters and Clams
Eggs
Salmon
Our top favorite plant foods to serve to babies that are high in iron are:
Chickpeas (hummus)
Lentils
Peas
Sweet potatoes
Aiming to offer iron-rich foods with most meals is the best way to try and meet the iron recommendations for babies and toddlers.
And remember, if your family follows a plant-based diet, larger quantities of iron-rich foods will be needed since non-heme iron foods have a lower absorption rate.
There is a lot more information like this in our Starting Solids Handbook:
Sources
Martinez-Torres V, Torres N, Davis JA, Corrales-Medina FF. Anemia and Associated Risk Factors in Pediatric Patients. Pediatric Health Med Ther. 2023 Sep 4;14:267-280. doi: 10.2147/PHMT.S389105. PMID: 37691881; PMCID: PMC10488827.
KC A, Rana N, Målqvist M, Jarawka Ranneberg L, Subedi K, Andersson O. Effects of Delayed Umbilical Cord Clamping vs Early Clamping on Anemia in Infants at 8 and 12 Months: A Randomized Clinical Trial. JAMA Pediatr. 2017;171(3):264–270. doi:10.1001/jamapediatrics.2016.3971
Site:
Hallberg, L et al. “The role of vitamin C in iron absorption.” International journal for vitamin and nutrition research. Supplement = Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Supplement vol. 30 (1989): 103-8.
Hallberg, L et al. “The role of vitamin C in iron absorption.” International journal for vitamin and nutrition research. Supplement = Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Supplement vol. 30 (1989): 103-8.
