Soy milk is a popular milk alternative for adults, but can babies drink soy milk too?

Soy milk is a popular alternative to regular cow’s milk and can be a great option for some adults, especially those who are lactose intolerant.

But what about non-dairy options like soy milk for babies and toddlers? Here’s everything you need to know about soy milk for babies, with examples and detailed guidance.

What Is Soy Milk?

Soy milk is made from cooked soybeans and contains soy protein, natural or added sugars, and fiber. While nutritional content can vary by brand, a 4-ounce cup of soy milk typically contains:

• 40 calories
• 3 to 4 grams of protein
• 2 grams of fat
• 0.5 grams of sugar

Soy milk also provides important minerals such as calcium, iron, and potassium, which are essential for overall health.

Should Babies Drink Soy Milk?

Babies under 1 year of age should not drink cow’s milk, soy milk, or any other plant-based milk. They should consume only breast milk or formula (with small amounts of water once they begin eating solid foods).

Cow’s milk contains too much protein and minerals for a baby’s stomach to handle, and most plant-based milks lack the critical nutrients that infants need early in life.

From ages 1 to 5 years, doctors recommend that children primarily drink cow’s milk and water. However, fortified soy milk is an acceptable alternative to cow’s milk because it is nutritionally similar.

If your child drinks soy milk between ages 1 and 5, ensure it is both fortified and unsweetened. For children aged 1 to 2 years, the recommended daily intake is 2 to 3 cups of whole milk (or equivalent).

For children with specific medical conditions—such as dairy allergies or lactose intolerance—or for families that avoid animal products, fortified soy milk can serve as a suitable substitute for cow’s milk.

Is Soy Milk Good for Babies?

You should not give soy milk to babies under 1 year of age. Unlike soy milk, breast milk and infant formula contain all the nutrients that infants require.

After 1 year of age, your child should primarily drink whole cow’s milk, but fortified, unsweetened soy milk is an acceptable alternative for families following a vegan diet or for children with dairy sensitivities or medical conditions.

Work with your pediatrician to identify the best type of soy milk for your child. Nutritional content can vary by brand, and experts note that our bodies may not absorb nutrients from plant-based milks as efficiently as they do from dairy milk. Your doctor can recommend the most suitable option.

Is Soy Milk Safe for Babies?

Babies under 6 months should only consume breast milk or infant formula. Once solid foods are introduced, they can drink small sips of water, but cow’s milk and soy milk are not suitable for infants.

After your child’s first birthday, you can give them unsweetened, fortified soy milk if they have dairy allergies, lactose intolerance, or follow a vegan diet.

Cow’s milk remains a vital source of protein, calcium, potassium, and vitamins A, D, and B12. In contrast, plant-based milks can have varying nutrient levels and—except for certain fortified soy milks—are not ideal substitutes for dairy milk.

When Can I Give Soy Milk to My Baby?

If your child has a dairy allergy, lactose intolerance, or is being raised vegan, you can introduce fortified soy milk recommended by your pediatrician starting at 1 year of age.

For children without medical issues or dietary restrictions, it’s best to avoid plant-based milks, including soy milk, until they are older. Major child health organizations in the United States advise against replacing cow’s milk with plant-based alternatives—except fortified soy milk—for children under 5 years.

Soy Milk vs. Cow’s Milk for Babies

When comparing nutrients, experts agree that cow’s milk offers more, cup for cup, than plant-based options. For example:

• 1 cup of whole cow’s milk contains 149 calories and 7 to 8 grams of protein.
• 1 cup of soy milk contains 105 calories and 6 grams of protein.

Cow’s milk also contains more fat and sugar:

• Cow’s milk: 8 grams of fat and 12 grams of sugar.
• Soy milk: 3.5 grams of fat and 9 grams of sugar.

When it comes to vitamins and minerals, cow’s milk provides:

• 276 mg of calcium
• 322 mg of potassium

Meanwhile, soy milk offers:

• 300 mg of calcium
• 298 mg of potassium

Soy Milk and Phytoestrogens

Soy milk contains compounds called phytoestrogens, also known as plant estrogens or isoflavones. Over the years, some studies have raised concerns about phytoestrogens being linked to breast cancer. However, other research suggests that isoflavones may actually protect against certain diseases, including breast, endometrial, and prostate cancer.

As for concerns about excessive phytoestrogen intake affecting children’s hormones, the journal Pediatrics (published by the American Academy of Pediatrics) emphasizes that there is no evidence that soy isoflavones negatively impact hormonal development in children.

Should I Give Soy Milk to My Baby if They Have a Dairy Allergy?

If your baby has a dairy allergy—a relatively rare condition affecting 2 to 3 percent of infants—or is lactose intolerant, you can give them fortified soy milk after their first birthday. However, it’s crucial to consult your pediatrician or a nutritionist, as the nutritional profile of soy milk can vary significantly by brand.

Soy Milk and Calcium

While some soy milks contain slightly more calcium than cow’s milk, they also have natural compounds called phytates that can interfere with calcium absorption. If your child drinks soy milk instead of cow’s milk, ask your pediatrician whether you should include other calcium-rich foods like spinach or fortified cereals in their diet.

When to Call the Doctor

Milk allergies in babies are rare, but it’s helpful to recognize the symptoms. Breastfed babies may react to milk in their mother’s diet, while formula-fed babies may react to the milk proteins in the formula itself. Signs of a milk allergy include:

• Frequent spit-up
• Abdominal pain
• Vomiting
• Diarrhea
• Blood in stools
• Wheezing or difficulty breathing
• Coughing
• Itchy, watery, or swollen eyes

Contact your pediatrician if you suspect your baby has a milk allergy.

While fortified soy milk can be a suitable substitute for some children, experts recommend that most kids stick to regular cow’s milk until at least 5 years old. Babies under 1 year should consume only breast milk or formula (with small amounts of water introduced alongside solid foods at around 6 months), and children older than 1 year should primarily drink unsweetened cow’s milk.