What We Know About Iron Supplements

Iron supplements for children may or may not benefit them so more research is needed

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Parents often worry if their children are getting all the nutrients they need. Vitamins and supplements help fill in the gaps, but only if those supplements actually benefit a child.

A recent study looked at the research available on giving children iron supplements. The researchers found that the information available on iron supplementation on preschoolers is not very helpful or extensive.

The supplements had no effect on a child's physical growth and only a tiny effect on their brain development, which was shown in a study with flaws.

In short, researchers don't know much about how iron supplements might help children, so more research is needed.

"Ask your pediatrician about supplements."

The study, led by Jane Thompson, BA, of the School of Medicine at University of Adelaide in Australia, aimed to understand what the benefits and risks might be of giving young children iron supplements.

The researchers analyzed all the available research with clinical trials on giving iron supplements to children aged 2 to 5. Out of 9,169 studies they initially looked up, only 15 met the criteria for being a randomized, controlled trial.

Further, none of these had a low risk of bias, which means it's possible other factors might have influenced the quality of the findings and made the findings less reliable.

In combining the data from all the trials, the researchers found that the children receiving iron supplements had an average 6.97 grams per liter more hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen throughout the body.

The children receiving supplements also had an average 11.64 micrograms per liter more iron in their blood. However, it's not clear whether this added iron and/or added hemoglobin actually did anything beneficial for the children.

None of the trials provided evidence related to whether iron supplements helped prevent children from having an iron deficiency or having anemia specifically related to an iron deficiency.

Anemia is a condition where a person does not have enough healthy red blood cells in their body. Only one of the trials looked at iron supplements and anemia and found that the iron supplements did not have an effect on a child's risk or improvement of anemia.

A small amount of evidence supported the idea that iron supplements might have slightly improved children's brain development, but the evidence was limited and weak.

There was no evidence found in this research that iron supplements had any effect on children's physical growth.

Overall, therefore, the researchers concluded that information regarding the benefits and risks of iron supplements for children is still lacking.

Although the supplements increased the red blood cell proteins and iron itself in the blood, there is no evidence that these increases make much of a difference to the child's growth or reduced risk of an iron deficiency.

The evidence regarding effects on brain development from iron supplements is so weak that more research is needed to understand it. More research is also needed on whether iron supplements do anything to help reduce a child's risk of anemia.

The study was published March 11 in the journal Pediatrics. The research was funded by a Victoria Fellowship from the Government of Victoria, a CRB Blackburn Scholarship from the Royal Australasian College of Physicians and an Overseas Research Experience Scholarship from the University of Melbourne.

One author received a research grant from Vifor Pharma Ltd and has been a consultant for the Meat and Livestock Authority Australia. The other authors declared no conflicts of interest.

Reviewed by: 
Review Date: 
March 10, 2013
Last Updated:
March 11, 2013