What Happens If You Give A Baby Cow’s Milk Too Early? (Side Effects & Why It’s Better To Wait A Year)

The American Academy of Pediatrics recommends no cow’s milk until after the baby’s first birthday. And after their first birthday, it’s recommended that you limit the amount of cow’s milk that your child receives to 2-3 cups (16-24 ounces) per day. Babies exposed to cows’ milk before their first birthday are more likely to be at risk of iron deficiency anemia, have diarrhea or vomiting, and experience allergic reactions. Cows milk is deficient in Vitamin C, E, and copper, and its excessive protein load can overload a baby’s kidneys. It does interfere with the absorption of iron and decreases a child’s desire for other foods. Cows milk is harder to digest as well, often causing intestinal blood loss.

Though milk is a popular drink worldwide, and nutritional manna for older children, it may seem surprising that cow milk isn’t recommended for infants from the word go. 

Cow’s milk is often easier to find and less expensive than formula milk. Serving it can feel like a big step for you and your child.

So by the time your baby turns one year old, you’re likely to be more than ready to make the switch. But, can you do it earlier? And what can you expect to happen once you start? 

Side effects of cow milk on younger children

Just because a food has nutrients or something we need doesn’t always mean that there are no bad qualities of that food. Below are a few common health impacts associated with feeding your child cow’s milk too early.

1. Nutritional deficiency 

Babies who drink unprocessed cow milk have significant iron deficiencies, linoleic acid, and Vitamin E.

Iron deficiency anemia is one of the most common and severe problems associated with cow milk consumption in children younger than one year. 

Untreated, this deficiency can lead to lifelong learning disabilities and delayed motor development.

Although the AAP notes that newborns and infants given iron supplements with cow milk may maintain normal iron levels, they insist that these do not address the overall nutritional adequacy of the babies’ diet.

2. Overnutrition

Newborns and infants given cow milk receive excessive levels of some nutrients and minerals.

Cow milk contains excessive electrolytes, potassium, and sodium, which regulate fluid intake.

It can overload a baby’s developing kidneys and cause serious illness when the little one loses fluids because of sweat and diarrhea, leading to dehydration.

Cow milk also contains significantly more protein than human breast milk, and a baby’s developing digestive tract can’t derive sufficient nutritional value from it.

3. Gastrointestinal irritation

An infant girl is crying because her stomach is upsetting her

Compounds in cow milk can irritate the lining of a baby’s stomach and colon. It can lead to abdominal pain and loss of blood in the baby’s stool.

Over time, blood loss from digestive irritation can cause or worsen iron deficiency anemia.

Certified lactation consultant Kelly Bonyatta also notes higher incidences of diarrhea and vomiting among babies drinking whole cow milk.

4. Allergic reactions

Infants given cow milk early in life are more likely to develop allergies than those fed breast or formula milk.

Cow milk’s high protein content substantially increases the likelihood of an allergic reaction compared to infant formula, which contains fewer allergenic compounds, says Bonyatta. 

Cow milk allergy may have long-term effects on the child’s overall nutrition, and in some instances, food allergies can be fatal.

5. Childhood constipation

Studies show that too early consumption of cow milk by infants may lead to chronic cases of constipation due to milk protein allergy. 

Why is it important to postpone cows’ milk until 12 months?

Mom is drinking water while breastfeeding her infant baby

It is tempting to introduce cow milk a little sooner than 12 months, but you shouldn’t jump ahead here.

Breast milk contains iron, Vitamin C, and other nutrients, same as formula milk, many of which aren’t in cows’ milk, at least not in high enough quantities for your little one to thrive.

However, when your baby reaches their first birthday, they can compensate for many of those lost nutrients with a quality solid foods diet comprising fruits, vegetables, lean protein, dairy, and whole grains.

Babies younger than 12 months old aren’t eating a ton of solids and are relying on breast and formula milk for their nutrient needs. Therefore, breastfeeding is still highly recommended on a supplemental basis.


What are the health benefits of cow’s milk on children?

If introduced at the appropriate age, cow’s milk is nutritious for babies as it has a good amount of calcium which is vital for developing strong bones, teeth, and muscle growth. It contains Vitamin D, which helps the absorption of calcium in the body. 

Milk also carries a high amount of protein which helps your baby grow, and carbohydrates give your child the energy they require throughout the day.

Appropriate amounts allow your baby to develop stronger bones, a healthy blood pressure, and a healthy heart.

Which type of cow milk is best for babies?

Until two years, children need to receive whole milk because fats are essential for their growth. Then a transition to low-fat milk or regular milk can be made, depending on the child’s weight.

Children who are overweight should be given low-fat milk from the start. 

Take away

Cow’s milk is neutral tasting but can be easily flavored and will provide your baby with essential nutrients once they turn one year old.

While feeding it to your baby too early is not recommended, milk-based products such as yogurt and cheese are still acceptable for babies below one year. 

The optimal food in infancy is breast milk. Knowing and avoiding the harmful effects cow milk reactions can have on your younger child is very important. 

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Hello, I am Emelda from Nairobi, Kenya. They simply call me mama Lilly. A fun of long road trips and a very good cook, along with my mommy duties to a super active girl. She inspires and challenges me in equal measure, and that is how I get to share with you our journey of triumph as we grow and tag you along.

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