How much iron do babies and children need?

lambbeetrootburgers_edited_smallThis is Part I of a two-part article about your children’s iron needs and the best foods to eat to ensure adequate iron intake. You can read Part II here.

Have you ever wondered if your child is getting enough iron, or thought about adding something to his or her porridge to ensure he gets enough iron? Doctors and midwives often warn about iron deficiency in children and the importance of an iron-rich diet. Many doctors and health agencies still recommend iron-fortified food, or the combination of iron-containing foods to maximize absorption. But is this good advice? We have read through many studies and expert conclusions to dig out the answers to your questions.

The UK’s Scientific Advisory Committee on Nutrition (SACN) recently published its findings in a report entitled ‘Iron and Health’ (1). The report was the culmination of many years of research examining studies from around the world. Although written from a UK perspective, these findings can be applied to other countries with similar standards of health and nutrition. Among the questions considered were the need for supplemental iron, the efficacy of combining foods on maximizing iron absorption, the dangers of too little and too much iron, the adequacy of current diet, the iron status of the UK population and the current advice to reduce intakes of red meat.

It is worth noting for Swedish readers of this blog that Livsmedelsverket still recommends iron-fortified foods until the age of 2 (2). Our research suggests that this advice is outdated. The UK (NHS) food guidelines on weaning no longer suggest the inclusion of iron-fortified foods.

General

Here are some of the SACN’s general findings:

  • The most important determinant of iron absorption from food is how much iron your body needs. Those who need iron the most will absorb it most easily from food and vice versa.

  • Iron status is difficult to measure conclusively. Current recommended intakes are based on over-cautious estimates and are probably too high.

  • There is no evidence to suggest that combining some foods and not others to increase absorption of iron (e.g. adding blood bread to porridge or not eating calcium or drinking milk with meat) has any benefit to the UK population. It may be beneficial in populations who are iron-deficient.

  • Some studies showed an effect when eating the simple meals that children often consume, such as a cheese sandwich (3), but not when consuming a wide variety of foods together, such a French meal consisting of milk, cheese, eggs, fruit, vegetables and bread (4). The SACN concluded that iron is best absorbed in the context of a nutrient-rich, varied diet and recommends such a diet for both children and adults.

    Children

    The main conclusions of the report that apply to children, taking into account all the major studies, are summarized as follows:

  • Babies born at term (38 weeks+) acquire enough iron during pregnancy to last the first 6 months of life. There is no evidence to suggest the need for iron-fortified foods or formula during this time.

  • A mother’s iron-deficiency has little or no effect on the iron content of breast milk and iron supplementation during lactation does not increase the iron content of breast milk (5).

  • Introduction to cow’s milk of infants aged 6 months is associated with small losses of blood from the intestinal tract (6). Introduction to cow’s milk in the first 12 months is associated with lower iron stores (serum ferritin levels) and lower hemoglobin levels (7), (our addition – which may be linked to the loss of blood from the intestines).

  • Iron supplements and fortified foods given to children who are not iron deficient may impair growth. A Swedish study showed that gains in length and head circumference were significantly lower in children given extra iron who were not iron deficient (8). An Indonesian study showed negative effects on weight gain (9) and an Indian study showed negative effects on both weight gain and linear height (10). The SACN concluded that more research was needed to examine the need for iron-fortified foods and suggest an upper limit.

  • The iron needs of premature babies require special consideration.

    Children under 3 were however considered one of the vulnerable groups and the SACN noted that suspected iron deficiency should be properly investigated.

    Giving too much iron to children who already have plenty may also affect developmental outcomes. The results of a long-term study undertaken over 10 years with children in Chile and reported in 2012 found that although the vast majority suffered no long-lasting effects, those who had the highest hemoglobin levels at the start of the study suffered poorer long-term development outcomes when given iron-fortified formula (11).

    In practical terms, what this means is that your child probably does not need any extra iron or iron-fortified foods in the first 6 months of life. Unless iron deficiency is confirmed, iron supplementation is best avoided. However, from 6 months onwards it is very important for your child to eat a balanced diet including vegetable and/or animal sources of iron with plenty of essential nutrients. It is also probably best to avoid giving cow’s milk products including milk, cheese and yogurt to children under 12 months although small amounts, for example in food, are unlikely to be harmful.

    In Part II we list the best naturally rich sources of iron for your growing child and give some easy tips and tricks to ensure he or she gets enough from his/her food.

    Below are two tables showing recommended iron intakes. The first shows the UK guidelines and the second the Swedish guidelines. They are somewhat similar, although the UK guidelines are a bit more specific. This is the amount of iron your child needs to eat in a day in order to absorb what he/she needs. The amounts are based on general assumptions about the amount of bioavailable iron in food and recommendations can vary a lot between countries. This is because different countries have different diets and different assumptions about the amount of iron absorbed. They include a good margin. It is worth noting that animal sources of iron are much better absorbed than non-animal sources. We discuss this in Part II.

    Iron needs by age (UK Guidelines) 
    AgeIron mg/(umol)/day
    7-9 months7.8 (140)
    10-12 months7.8 (140)
    1-3 years6.9 (120)
    4-6 years6.1 (110)
    7-10 years8.7 (160)
    Males 11-14 years11.3 (200)
    Females 11-1414.8 (260)
    Males 15-18 years11.3 (200)
    Females 15-18 years14.8 (260)
    Males 19-508.7 (160)
    Females 19-5014.8 (260)
    50+8.7 (160)


    Source: UK’s Scientific Advisory Committee on Nutrition

    Iron needs by age (Swedish RNI) 
    AgeIron mg/(umol)/day
    Children8-11 (140-193)
    Males9 (158)
    Females of child-bearing age15 (264)
    Breastfeeding women15 (264)
    Females not of child-bearing age9 (158)


    Source: Livsmedelsverket

    References

    1. http://www.sacn.gov.uk/pdfs/sacn_iron_and_health_report_web.pdf

    2. http://www.slv.se/sv/Fragor–svar/Fragor-och-svar/Mat-for-smabarn/Varfor-behover-barn-sa-mycket-jarn-och-hur-far-de-tillrackligt/

    3. Hallberg L, Brune M, Erlandsson M, Sandberg AS, Rossander-Hulthén L. Calcium: effect of different amounts on nonheme- and heme-iron absorption in man. Am J Clin Nutr 1991;53:112–9. Online: http://ajcn.nutrition.org/content/53/1/112.full.pdf+html

    4. Galan P, Cherouvrier, F Preziosi, P Hercberg S. Effects of the increasing consumption of dairy products upon iron absorption. Eur J Clin Nutr. 1991; 45 (11):553-559 Online:http://www.ncbi.nlm.nih.gov/pubmed/1782927

    5. Kalkwarf HJ, Harrast SD. Effects of calcium supplementation and lactation on iron status. Am J Clin Nutri-1998;67(6): 1244-1249 Online: http://www.ncbi.nlm.nih.gov/pubmed/9625100

    6. Ziegler EE, Fomon SJ, Nelson SE, Rebouche CJ, Edwards BB, Rogers RR, Lehman LJ. Cow milk feeding in infancy: further observations on blood loss from the gastrointestinal tract J Pediatr. 1990; 116(1):11-18 Online:http://www.ncbi.nlm.nih.gov/pubmed/2295949

    7. Sullivan, PB Cows’ milk induced intestinal bleeding in infancy. Arch Dis Child. 1993 68 (2:240-245) 1993; Robson, 1993; Michaelsen et al, 1995; Zlotkin, 1993

    8. Dewey KG, Dommellöf M, Cohen RJ, Rivera LL, Hernell O, Lönnerdal B. Iron supplementation affects growth and morbidity of breast-fed infants: results of a randomized trial in Sweden and Honduras. J Nutr 2002;132:3249–55. Online: http://www.ncbi.nlm.nih.gov/pubmed/12421836

    9. Lind et al, 2004: Am J Clin Nutr September 2004 vol. 80 no. 3 729-736 Online: http://ajcn.nutrition.org/content/80/3/729.long

    10. Majumdar et al. (2003). The effect of iron therapy on the growth of iron-replete and iron-deplete children. Journal of Tropical Pediatrics, 49, 84.

    11. Iron-fortified vs low-iron infant formula Betsy Lozoff, MD; Marcela Castillo, PhD; Katy M. Clark, MA; Julia B. Smith, EdD Archives of Pediatrics & Adolescent Medicine, Nov. 7, 2011, doi:10.1001/archpediatrics.2011.203. Online: http://archpedi.jamanetwork.com/article.aspx?articleid=1107714

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