Alvin N. Eden, MD
One of the true success stories in infant nutrition has been the almost complete elimination of iron deficiency during the first year of life. This has been largely due to an increase in the prevalence of breastfeeding and the use of iron fortified formulas. Further, using iron-fortified cereals and juices (vitamin C enhances iron absorption) also contribute to maintaining adequate iron intake for the first 12 month of life. But sad to say the same success story is not the case in one to three year olds.
The problem appears to be the fact that routine testing for iron deficiency is not being carried out. The current "screen and treat" recommendations of the American Academy of Pediatrics only includes tests for iron deficiency anemia (a hemoglobin or hematocrit), but not testing for iron deficiency. This approach only identifies those toddlers who are anemic and does not pick up the one to three year olds who are iron deficient without being anemic. (There are about three cases of iron deficiency for every one case of iron deficiency anemia).
It is very important for parents to understand why they must do everything possible to help prevent their young child from ever becoming iron deficient. Unfortunately, large numbers of toddlers (ages one to three) in the U.S. today have been found to be iron deficient. Three separate studies have shown that about one out of every three toddlers (especially those among lower socio-economic groups) suffer with some degree of iron deficiency.
This high prevalence of iron deficiency during the toddler years comes as no great surprise. A number of dietary changes that often occur around one year of age make the toddler particularly vulnerable to iron deficiency due to inadequate iron intake. These changes include:
1. The switch from breast milk or iron-fortified formula to regular cow's milk which is very low in iron as compared to both breast milk and iron-fortified formula
2. The use of adult-type non-iron fortified cereals in place of infant iron-fortified cereals (by law in the U.S. all infant cereals must be iron fortified)
3. The normal physiologic toddler decrease in appetite for solid foods, along with an increased intake of cow's milk, often more than 24 ounces per day, as well as the drinking of large quantities of various juices that do not contain iron
So why is it so important to prevent iron deficiency during this period of rapid brain growth? There are two reasons:
1. Several studies have clearly demonstrated that iron deficiency anemia and iron deficiency impair mental and psychomotor development in infants and toddlers. Further, follow up studies years later have shown that these deficits are long lasting and possibly irreversible, despite the correction of the iron deficiency.
2. Two very recent large scale investigations have proven that iron deficiency increases lead absorption. In other words, an iron deficient toddler will absorb more lead from the environment than an iron sufficient toddler exposed to the same amount of lead. It is well known that lead poisoning can result in a permanent loss of I.Q. points. The higher the blood lead level the more damage to the developing brain.
Until very recently blood lead levels of 10ug/dL (micrograms per deciliter) or below were considered harmless, but we now know better. Two recent large scale studies have shown that lead-associated cognitive deficits occur even at blood lead levels below 10ug/dL. These investigations determined that the I.Q. deficits observed with each one ug/dL increase in blood lead concentration were greater at blood lead levels below 10ug/dL than at higher blood lead levels. Of particular concern are the results of a current study showing that 32% of a large group of one to two year olds tested were found to have blood lead levels above 5ug/dL. What all this means is that we must try to keep our young childrens' blood lead levels as low as possible, the lower the better. It is a lot easier to help protect against lead absorption by simply preventing iron deficiency than it is to try to get rid of all the environmental lead around your child which, of course, is impossible.
In my opinion a routine daily supplement of 10mg of elemental iron via iron-fortified vitamin drops starting at the time the baby is switched to regular cow's milk is the best approach to the prevention of iron deficiency. It is easy, safe, and effective and should be continued to age three. The possibility of long-lasting mental and psychomotor impairment associated with iron deficiency as well as the increased lead absorption associated with iron deficiency in this age group makes prevention an important public health problem.
Why would we want our young children to be at risk? If you are a parent of a toddler, I would strongly suggest that you discuss the whole subject of iron deficiency with your child's physician.
Dr. Eden is the chairman of the Department of Pediatrics, Wyckoff Heights Medical Center, Brooklyn, New York and a Clinical Professor of Pediatrics, Weill Cornell Medical Center, New York, NY. His practices in Forest Hills, NY. He is the past chairman of the Section on Pediatrics, New York Academy of Medicine.
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