Excessive milk intake
The recommended amount of cow’s milk for children one year of age 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. Children who continue to drink milk from a bottle past the age of two tend to drink too much milk and have a higher likelihood of developing iron deficiency.
A small group of these children may 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 hemoglobin. Hemoglobin 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 hemoglobin 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 and irritability.
Protein losing enteropathy from cow's milk
Drinking too much cow's 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 levels of a protein called albumin in the blood.
Having low levels of albumin in the blood 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.
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
Symptoms of protein losing enteropathy and low albumin 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 and nutritional needs, 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 excessive milk intake leads to protein loss in the gut in some children with iron deficiency anemia. It is not thought to be a cow's milk protein allergy.
Diagnosis of anemia and protein losing enteropathy
Iron deficiency anemia
Iron deficiency anemia can be diagnosed by your child’s health-care provider. 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.
Protein losing enteropathy
Protein losing enteropathy is suspected in children with swelling and low albumin levels in the blood. Your child’s health-care provider will examine them for swelling of the legs, feet and face. They will also examine your child’s heart, lungs and abdomen.
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.
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. Offering milk during the day (not at night or in bed) by sippy cup is best. Avoiding milk bottles during sleep will also help prevent tooth decay and sleep problems.
Iron rich foods are an important part of treating 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 health-care provider might also prescribe iron supplements. After a few weeks, values such as the hemoglobin 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 and constipation. Talk to your child’s health-care provider or a pharmacist about how to reduce side effects from the treatment.
Dairy products (e.g., 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
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, severe anemia can cause a stroke.
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, know that children may have temporary difficulty soothing themselves to fall asleep without a bottle, but will adapt to a new routine. Some children may need a bottle of water initially, but will slowly adapt to falling asleep without it. Removing your child’s bottle before bed and during the night will help them avoid dental caries. Teaching them to self-soothe without a bottle will help them learn to sleep through the night without waking.
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 child's health-care provider 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.
Reference
Unger, S.L., Fenton, T.R., Jetty, R., Critch, J.N. & O’Connor, D.L.; Canadian Paediatric Society, Nutrition and Gastroenterology Committee. Iron requirements in the first 2 years of life. Canadian Paediatric Society, March 26, 2025. https://cps.ca/en/documents/position/iron-requirements