Why iron and vitamin A are important for babies
Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient" with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. What happens when a baby does not get adequate amounts of iron or vitamin A? For help answering this question, I turned to Dr. Aamer Imdad, an assistant professor of pediatrics specializing in gastroenterology. Dr. Imdad, welcome to "The Informed Patient".
Aamer Imdad, MBBS: Thank you for having me.
Let's start by first talking about what iron is and why we need it in our diets. I understand it's a mineral, but what does it do?
Well, iron, indeed, is a mineral that the body needs for growth and development. So, it is important for hemoglobin, which is a protein in the red blood cell that carries oxygen from the lungs to all parts of the body. It also plays a very important role in another protein called myoglobin, which is a protein that provides oxygen to the muscles. Iron is also involved in a bunch of hormones as well. So it's very critical to have adequate amount of iron in the body for proper functioning.
Host Amber Smith: Now, there are foods that are rich in iron, is that right?
Aamer Imdad, MBBS: That is correct.
Host Amber Smith: Are the dietary sources as good as supplements?
Aamer Imdad, MBBS: Well, let me go back and explain a little bit more about that. So the iron could be available in the heme form, which is the most bioavailable. And then there is a non-heme form. So the heme form comes typically from the animal products, like, for example, lean meat or seafood, poultry. And then the non-heme source comes from the plant base, like beans, lentils, spinach, kidney beans, peas and some of the nuts as well. Now the fortification that happens actually has more of the heme component to it. And heme is more bioavailable than the non-heme part of it. So putting this together, the bio availability of iron is better from the animal source. However, if the animal source and the plant-based source of iron is taken together, the bio availability increases even further.
Host Amber Smith: How much iron do we need? And does that change for if, as a baby going into toddlerhood, teen years, adult, seniors... does it change over the lifespan?
Aamer Imdad, MBBS: That is correct. So the recommended daily average amount that is needed is different based on the age and gender as well. For very young babies, so the babies that are born full term and are less than six months, they actually have adequate amount of iron that they had stored from the mother. So an average requirement for a baby less than six month is only 0.27 milligrams per day. However, for babies older than that, for example, seven to 12 months, it goes up to 11 because they're rapidly growing. And then children say, 1 to 3 years, it's about seven milligrams per day. And then older kids, like in teenagers, for example, the teen boys have about 11 milligrams, and the teen girls on the other hand about 15 milligrams per day. The requirement kind of decreases in older age group. For example, for adults more than 50 years of age, the requirement is only about eight milligrams per day. Pregnant females and breastfeeding mothers have additional requirements for iron because of the requirements of pregnancy and lactation.
Host Amber Smith: Why do young women need more iron than young men?
Aamer Imdad, MBBS: It is mainly related, so for adolescent females, for example, they are developing, in terms of their secondary sexual characteristics, and also the blood loss during menstruation plays an important role. So, the young woman of reproductive age requires more iron, say, compared to their age-matched males.
Host Amber Smith: Now what happens if a person doesn't get enough iron?
Aamer Imdad, MBBS: It depends on the extent of the deficiency. So you can have marginal deficiency, which actually won't lead to a whole lot of symptoms, other than, say, just being fatigued or tired or, in very young kids, they may be more irritable, but if you develop severe deficiency, then you can develop iron deficiency anemia, which is the decrease in the red blood cell mass in the body. And depending on age, it can lead to symptoms like lethargy and inability to play in very young kids to grownups, where they may not be able to perform their daily activities.
Host Amber Smith: Do you ever see people who have too much iron, and is that a problem?
Aamer Imdad, MBBS: Sometimes it is. It is not very often, that there is an excessive iron intake. However, some of the supplementation, if taken over longer period of time, can lead to iron toxicity. Interestingly, in very young kids, sometimes they can overdose on the tablets that their parents had. For example, if the mom is pregnant for another baby, and the younger baby consumes the tablets that mom is supposed to take, that can lead to toxicity. And, uh, it used to be one of the common causes of toxic overdose in young kids. And it has decreased over time because the way the tablets are packaged now. Previously, they were actually sugar coated. And nowadays they are not. And that has helped decrease the incidents where the over ingestion can lead to severe complications in very young children.
Host Amber Smith: Well, now I'd like to focus on some research that you and your colleagues in Syracuse and elsewhere were involved in. You were assessing the iron content in a food product that is used to treat malnutrition, is that right?
Aamer Imdad, MBBS: That is correct.
Host Amber Smith: What were you looking for?
Aamer Imdad, MBBS: So we responded to a call from a World Health Organization -- and I'm going to call it W H O, from here onwards -- so the WHO is interested to issue its guidelines on how to treat severe acute manlnutrition in children, especially in low and middle income countries. Now, when the children, especially very young children, develop severe acute malnutrition, which is defined based on their weight for their height, if it is less than the standard weight for height for their age, say, there is a term called Z score, which is a standard score that you're supposed to have for that age. If the weight for height is below three standard deviations from that standard, then you are thought to have severe acute malnutrition.
Now the kids who have severe acute malnutrition, more than half of them have severe iron deficiency related anemia, which is the low blood counts. That is a risk factor for not only having an increased risk of infection, but also the risk of death is higher in children who have severe anemia. So, historically, these children who have severe acute malnutrition were treated inpatient. But more recently the W H O and other organizations like UNICEF (the United Nations Children's Fund) are trying to treat these children in the community setting because there are too many in numbers, and the resources are not available.
So in order to be treated in the community setting, they are fed something called ready-to-use therapeutic foods called RUTF. Now, RUTF are these dried peanut based food product that has all the macronutrients. The macronutrients are the proteins, the carbohydrates and the fat. And it also has the micronutrients, including the iron, zinc and other important minerals that are needed for growth. Now, historically there was about 10 to 12 milligrams of iron per 100 grams of RUTF, but the studies have shown that this much of iron may not be enough to treat the amount of anemia or iron deficiency that is there in the children with severe acute malnutrition.
So we were asked to evaluate and look at the studies that have used higher doses of iron, like, say, up to 50 milligrams per 100 grams of RUTF, and if that has a better effect on treatment and prevention of anemia in these children. And what we concluded was that the higher dose indeed iseffective in treating the anemia in these children. And that is a potential avenue for future research, because the number of studies were small, but the data that is available, indeed, shows that the risk of anemia could be lower with increased dose of iron, in this study to use therapeutic foods.
Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm talking with Dr. Aamer Imdad. He's an assistant professor of pediatrics who specializes in gastroenterology at Upstate, and he's been involved in research that looks at the iron content in food products. Now, you were describing a product that the World Health Organization recommends, ready-to-use therapeutic foods for infants. Is that a product that's available in the United States?
Aamer Imdad, MBBS: We typically don't use that in high income countries, including United States. The risk factors for malnutrition are kind of different in low and middle income countries compared to high income countries. Having said that, the resources available in developed countries are much more easily available, and the food insecurity and the community prevalence of infectious disease is lower in higher income countries, so the number of children who have severe acute malnutrition is actually much smaller in high income countries like United States. So we end up treating them with the traditional foods that we have depending on the age. For example, for very young kids, we have infant formulas that we can feed by mouth, or if we need to use a feeding tube, like a nasogastric tube or a gastrostomy tube. So we can help them go through nutritional rehabilitation with the resources.
In low and middle income countries, there is really not that many resources that are available. So these products which are readily available, that require minimal preparation or storage needs are advocated so that these kids could go through rehabilitation and could be prevented from complications, including this for infectious disease and possible death.
Host Amber Smith: Well, let me ask you about breastfeeding. Do babies get adequate iron if they're exclusively breastfed for the first two years of life?
Aamer Imdad, MBBS: It depends on the age. As I mentioned earlier, the babies who are born full term actually have a fair amount of iron stored in their body tissues, and they require minimal amount of iron. So for the first four months or so, if a full term baby is exclusively breastfed, they don't need additional iron. However, after that, the American Academy of Pediatrics recommends to supplement the exclusively breastfed babies to have about 1 milligram per kilogram per day of iron. It is specifically further recommended for kids who may not be able to consume the complementary feedings, which is the feeding that is started somewhere around four to six months of age that does not have enough of the iron source in it. So those babies are at a higher risk of developing iron deficiency anemia, and the academy recommends the supplementation and advocates for diverse type of foods that have iron in it to prevent the iron deficiency anemia.
The older kids are at a relatively lower risk because as the kids grow, they eat more diverse types of diets. It is less likely to have iron deficiency later in life, like after 1 year of age. However, if the diet is not diverse, then there are at high risk of developing iron deficiency anemia.
Host Amber Smith: Well, Dr. Imdad, you've also done research on the role of vitamin A in children under age five. Can you tell us about that?
Aamer Imdad, MBBS: So vitamin A is another essential micronutrient. An essential micronutrient is a micronutrient that is required in small quantities, but the body itself cannot synthesize it, so it has to be taken externally. So there are about 190 million children around the globe that have vitamin A deficiency. And vitamin A deficiency can increase your risk of infectious diseases, especially due to diarrhea, measles and pneumonia. It is also actually the most common nutritional cause of blindness in children and grownups. So vitamin A supplementation can help prevent this infectious disease and the blindness in young children. So we synthesized the evidence on vitamin A supplementation in children, 6 to 59 months of age. This work was invited by WHO, and we initially published that back in 2011, and we have done more updates on that. And based on our work, the WHO currently recommends the supplementation for vitamin A in children who are at least 6 months of age, that they get a dose of about 50,000 international units every six months. And the kids who are more than 1 year of age to get about 100,000 international units every six months to help treat and prevent vitamin A deficiency.
Host Amber Smith: How would you advise a mom to tell whether her baby is getting adequate iron and vitamin A? Are there tests? Do pediatricians look for this at regular exams?
Aamer Imdad, MBBS: The deficiency of iron and vitamin A in high income countries like United States is actually rare, so in an otherwise healthy, developing child, the risk of deficiency of these micronutrients is low. Now, having said that, there are certain scenarios where the risk of deficiency might be higher, such as some of the gastrointestinal diseases like celiac disease or Crohn's disease or ulcerative colitis. Sometimes the conditions that affect the pancreas can also lead to deficiency of these micronutrients. Some of the children who are on spectrum, of autism spectrum disorders, those kids might have sensory issues and limit their food to very specific foods. And if the diet is not diverse, then these children can develop micronutrient deficiencies.
So the things to look for, say, for example, for iron, the kid may not be very playful, or they may be just tired. They might look very pale. For vitamin A deficiency, their skin might get really dry. Sometimes they develop really significant dryness of their eyes. If they have difficulty seeing at night, that is highly concerning for vitamin A deficiency, and immediate attention should be given to that child, and a doctor should be consulted for further evaluation.
Host Amber Smith: I know your specialty is gastroenterology. What impact does vitamin A have on digestion?
Aamer Imdad, MBBS: Vitamin A plays important role in a number of functions in the body overall that the gastrointestinal tract is in the frontline in terms of receiving the nutrition and then processing it, leading to proper absorption. So vitamin A is a fat soluble vitamin, which means that it is only soluble through the fat, and there is a separate process for fat soluble vitamins compared to, say, water soluble vitamins, like for example, vitamin B12 or B6, or vitamin C, for example, or water soluble vitamins compared to vitamin A, which is more fat soluble. So if there is any dysfunction in the gastrointestinal tract where the digestion of the fat part of the diet is disrupted -- for example, in liver disease or in pancreatic disease, or, say, in celiac disease -- then the risk of developing vitamin A deficiency is higher in those conditions.
Host Amber Smith: What impact does iron have on digestion?
Aamer Imdad, MBBS: Iron, again, has a significant role. It obviously is a major part of the red blood cells, and it increases their oxygen carrying capacity. It also increases the storage capacityfor muscles in terms of the way they use the oxygen. The absorption of iron in gastrointestinal tract involves a number of different sites, including the stomach and the very last part of the small bowel terminal ileum. So if there is any defect or diseased part of the gastrointestinal tract where the absorption of, say, iron happens, then that can lead to iron deficiency anemia. Similarly, if there is an overdose of iron, say, for any given age, if the iron was given more than 20 milligrams per kilogram, that can cause significant gastrointestinal problems, including the acute bleeding and risk of death. The iron supplements that are typically taken, say, during pregnancy or for treatment of iron deficiency anemia can cause nausea and abdominal pain. Sometimes it can cause constipation or blood in the stool. Iron is very tightly controlled as it goes through the gastrointestinal tract. And, more than a typical dose can cause a mild to moderate, to severe symptoms, depending on how much is the iron in terms of when it was taken.
Host Amber Smith: Well, thank you so much for taking the time to talk with me about this, Dr. Imdad.
Aamer Imdad, MBBS: My pleasure. Thank you for having me.
Host Amber Smith: My guest has been assistant professor of pediatrics, Dr. Aamer Imdad. He specializes in gastroenterology at Upstate Medical University. "The Informed Patient" is a podcast covering health, science and medicine brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe. Find our archive of previous episodes at Upstate.edu/informed. This is your host, Amber Smith, thanking you for listening.