Excessive milk intake
The recommended amount of cow’s milk for toddlers is 250 to 500 mL (1–2 cups or 8–16 oz.) per day. Some toddlers drink more milk than the recommended number of servings. This "milk diet" can lead to iron deficiency. A small group of these children also experience protein loss from the digestive system or gut. Iron deficiency can lead to anemia (low red blood cell count) and protein loss leads to hypoalbuminemia (low levels of albumin in the blood). Treatment usually requires limiting milk intake, offering iron rich solid food, and in children with moderate to severe anemia, iron supplements.
Breast milk or formula is a good source of iron for the first six months of life. Iron stores in babies naturally decrease by four to six months of age. After six months, the amount of iron in breast milk is not enough, and solid foods are usually introduced.
When introducing solid foods, infants should start with meat or meat alternatives, in order to get enough iron and protein in their diet. Meat alternatives include fish, egg yolk, tofu, lentils and cheese. Iron-fortified cereals are also a good source of iron that can be started at four to six months of age. Breast milk and/or formula should continue until nine to 12 months of age, when homogenized (3.25%) cow’s milk may be started to complement solid food.
Iron deficiency anemia
Iron is an important mineral that we get from our diet that is needed to make haemoglobin. Haemoglobin is a protein in red blood cells that allows the cells to carry oxygen to the tissues in our body. Anemia occurs when you have low levels of haemoglobin in your body. When the anemia is caused by not having enough iron this is called iron deficiency anemia.
When a child has anemia, they are not getting enough oxygen delivered to the tissues in their body. This can cause them to look pale and tired, and cause weakness.
Protein losing enteropathy
Drinking too much milk can also cause protein loss from the gut (protein losing enteropathy).
Children with protein losing enteropathy have severe protein loss through the gut and this results in low protein levels in the blood.
The main protein found in the blood is called albumin. Having low levels of the protein albumin in the blood (hypoalbuminemia) can cause the blood vessels to leak fluid into the tissue. Extra fluid in the tissue can cause swelling (edema) of the legs, back and face. Hypoalbuminemia also puts you at risk for infections.
Hypoalbuminemia and edema can be caused by other disorders. Your child’s doctor will ask questions about your child’s overall health, symptoms of diarrhea or blood in the stool, and family history of gut, liver, kidney or heart diseases.
If there are no other causes for protein loss, it is possible that too much milk is the cause.
Signs and symptoms of iron deficiency anemia and protein losing enteropathy
Symptoms of anemia depend upon its severity, how fast the drop in levels of haemoglobin occurred and its cause. It also depends on how well a child’s body adapts to a low level of haemoglobin.
Symptoms of anemia include:
- pale skin
- lack of energy
- shortness of breath after exercise or play
Protein losing enteropathy and hypoalbuminemia causes the blood vessels to leak fluid into surrounding tissue.
Symptoms of protein losing enteropathy and hypoalbuminemia include:
- progressive swelling of the feet, legs and face
- muscle cramps or weakness
- extra fluid around the lungs (pleural effusion)
- swelling of the abdomen (ascites)
Risk factors and prevalence of iron deficiency anemia
Iron deficiency anemia is the most common type of anemia.
Around the world, iron deficiency anemia affects approximately 750 million children. In Canada, it is seen in 3.5% to 10.5% of the general population. Children have a greater risk of iron deficiency anemia due to their rapid growth, particularly in the first two years of life.
Children who are most at risk of developing iron deficiency anemia are those who are fed only breast milk or non-iron fortified cow’s milk formulas after six months of age, and those who drink an excess of cow’s milk. Children who are given cow’s milk before 12 months may also be at increased risk of developing iron deficiency anemia because their gut may not be ready to digest cow’s milk yet.
Cause of iron deficiency anemia and protein losing enteropathy
Iron deficiency anemia
Iron deficiency anemia from excessive milk intake is caused by three things.
- Not enough iron: Milk contains very little iron. In addition, if a child drinks too much milk, they will be too full to eat good amounts of iron rich foods.
- Poor iron absorption: Milk and other dairy products can interfere with the gut’s ability to absorb iron from other sources, such as meat and meat alternatives, and dark green vegetables.
- Microscopic bleeding: Too much milk can damage the lining of the gut (milk enteropathy). Milk enteropathy causes microscopic bleeding from the gut that you may not be able to see. Any type of bleeding from the body results in a loss of iron. Over time, this bleeding can cause very low levels of haemoglobin, contributing to the iron deficiency anemia.
Protein losing enteropathy
It is not fully understood how milk intake leads to protein loss in the gut. One theory suggests a process called villous atrophy. The small intestine part of our gut has finger-like projections on its walls called villi. The villi play an important role in the absorption of nutrients. It is believed that an excess intake of cow’s milk can cause the villi to shrink (villous atrophy) and not absorb nutrients well. Villous atrophy causes the bowel walls to become leaky, allowing protein to leak through.
Diagnosis of anemia and protein losing enteropathy
Iron deficiency anemia
Iron deficiency anemia can be diagnosed by your child’s doctor. They will do a physical exam and ask about your child’s energy levels, general health, diet and family history.
A blood test, called a complete blood cell count (CBC), can make the diagnosis of anemia by measuring haemoglobin levels. When the anemia is caused by iron deficiency, the red blood cells will also look smaller and lighter in colour when seen under a microscope.
A ferritin test may also be done. Ferritin is a protein found in the body that stores iron. A low ferritin level can indicate iron-deficiency.
Additional useful tests that measure the body’s iron are called iron studies.
Protein losing enteropathy
Protein losing enteropathy and hypoalbuminemia are suspected in children with swelling and low albumin levels in the blood. Your child’s doctor will examine them for swelling of the legs, feet and face. They will also examine your child’s heart, lungs and abdomen for extra fluid.
A blood test is often done to check the blood albumin level. A urine test may also be done to make sure there is no protein loss from the kidneys. When the cause of low albumin is not clear, further tests may be done including stool tests. One of the stool tests that may be performed is a 24-hour collection of stool to check for a protein called alpha-1-antitrypsin. By comparing the amount of this protein in the stool to the amount in the blood, doctors can tell whether there is protein loss through the gut.
Treatment of iron deficiency
Diet
Limiting milk intake to a maximum of 16 ounces per day is usually the only treatment needed. The iron levels will gradually rise and protein loss from the gut will decrease.
Iron rich foods can also help to treat iron deficiency. Many iron rich foods, such as meat and meat alternatives, are also high in protein. Offer your child foods such as meat and meat alternatives, and iron-fortified cereals a few times each day. From one year of age, young children should begin to have a regular schedule of meals and snacks. In general, you may follow the advice in Canada’s Food Guide.
Limiting milk does not mean stopping it completely. It is known that milk is a good source of calcium, vitamin A and vitamin D. From one to two years of age, children should drink 250 to 500 mL (1–2 cups or 8–16 oz.) of homogenized (3.25% M.F.) cow’s milk per day. They should not drink more than 500 mL (2 cups or 16 oz.) per day.
Iron supplement
Your child’s doctor might also prescribe iron supplements. After a few weeks, values such as the haemoglobin level generally start to improve. Treatment is usually continued for at least three months to fully replenish iron stores in the body.
Iron supplementation can cause an upset stomach. Your doctor might divide the dose in half and ask you to give it two times per day instead of as one large daily dose.
Dairy products (milk, cheese, yogurt) can have a negative effect on the absorption of iron. Try to give iron supplements two hours before or after eating or drinking any dairy products.
Vitamin C can help iron absorption from foods. Oranges and other citrus fruit are good sources of vitamin C. Be careful with offering too much juice, as it is high in sugar.
Protein losing enteropathy and hypoalbuminemia caused by too much milk gets better fairly quickly when the milk intake is limited to an appropriate amount.
Complications of anemia and hypoalbuminemia
Untreated anemia in children can have serious effects on a child’s growth. Untreated anemia can affect intellectual ability and overall development. This can lead to problems with attention, reading ability and school performance. In rare cases, extreme anemia can cause a stroke.
Hypoalbuminemia can also have serious effects on a child’s growth. Excess fluid around the lungs can cause problems with breathing. In rare cases, excess fluid can build up around the heart making it harder for the heart to pump. Protein loss in the gut can also cause a loss of the proteins needed to fight infection and prevent clots, putting children at risk of severe infections or blood clots.
Helping your child
Limiting milk intake can be challenging. Many toddlers enjoy drinking milk in a bottle, and associate drinking milk with their bedtime ritual.
Here are some tips on how to help limit your child’s milk intake:
- If your child drinks more than 1200 mL (5 cups or 40 oz.) of milk per day, wean them slowly to smaller amounts. Cut the amount by half to start.
- Offer solid foods first and only offer milk at the end of the meal. Alternatively, you could offer water with meals and milk only a couple of times a day with a snack. This way your child will not fill up on milk first.
- Switch to a sippy cup early. This will prevent your child from taking the milk to bed and associating drinking milk with falling asleep.
- Do not allow your child to sleep with a bottle of milk in bed. If you are having trouble with this then slowly start to dilute the milk with water until you are offering just water. This will also help in avoiding dental caries.
Follow-up
Iron supplementation should be continued for at least three to six months to replenish the amount of iron that is stored in the body.
After starting treatment, your doctor will schedule a follow-up appointment. A repeat blood test is not always needed if your child’s symptoms improve with iron treatment and changes in diet.
Virtual care services for children
Boomerang Health was opened by SickKids to provide communities in Ontario with greater access to community-based services for children and adolescents. For more information on virtual care services in Ontario to support anemia, visit Boomerang Health powered by SickKids.
References
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- Allen, R.E. & Myers, A.L. Nutrition in Toddlers. American Family Physician. 2006; 74(9): 1526-1532.
- Bondi, S.A. & Lieuw, K. Excessive Cow’s Milk Consumption and Iron Deficiency in Toddlers: Two Unusual Presentations and Review. Infant, Child, & Adolescent Nutrition. 2009; 1(3). DOI: 10.1177/1941406409335481.
- Critch, J.N. Nutrition for healthy term infants, six to 24 months: An overview. Paediatric Child Health. 2014; 19(10): 547-549.
- Food Sources of Iron. Dietitians of Canada. (Accessed December 3, 2017).
- Grueger, B. Weaning from the Breast. Paediatric Child Health 2013; 18(4): 210.
- Kazal, L.A. Prevention of Iron Deficiency in Infants and Toddlers. American Family Physician. 2002; 66(7): 1217-1224.
- Rabinowitz, S. & Ebigbo, N. Pediatric Protein-Losing Enteropathy. Medscape, Pediatrics; General Medicine, 2017 < https://emedicine.medscape.com/article/931647-overview> (Accessed December 3, 2017).