Why Soy Milk Is the Best Dairy Alternative for Plant-Based Diets


Dairy contains nutrients like calcium and vitamin D that support your teeth and bones, but if you’re not a fan of dairy, there’s a good alternative: fortified soy milk.

Soy milk is the only plant-based milk alternative that fits into the dairy category, according to the United States Department of Agriculture (USDA). Other plant-based milk like almond, oat, hemp, and pea milk don’t count toward the dietary recommendation that calls for three cups of dairy per day.

“Both cow’s milk and soy beverage fortified with calcium are good sources of calcium, protein, potassium, and magnesium,” Connie Weaver, PhD, a distinguished research professor in exercise and nutritional sciences at San Diego State University, told Verywell in an email.

Soy milk is also the only plant-based dairy alternative that has been studied to assess how well calcium is absorbed, according to Weaver.

The calcium absorption rate is the same between cow’s milk and soy beverages fortified with calcium carbonate, Weaver said. If a soy beverage is fortified with tricalcium phosphate, the calcium absorption rate is significantly lower, but it’s still a good source of calcium, she added.

It’s important to make sure the soy milk you’re buying is fortified if you’re looking for a dairy alternative, experts say.

“Look to see if it’s fortified with calcium and vitamin D because some soy beverages are not and you’re not getting any benefit if there’s no fortification,” Sherry Gray, MPH, RD, a registered dietitian and a nutrition educator at the University of Connecticut, told Verywell.

While flavored soy milk contains added sugars, unsweetened soy milk has similar calories, protein, calcium, vitamin D, and vitamin A to those in cow’s milk, according to Gray.

“Of all the plant milks, soy milk is definitely the closest to dairy,” she said.

Isn’t Soy Milk Ultra-Processed?

Soy milk can be considered an ultra-processed food based on NOVA, the main system used to categorize foods by levels of processing. This may be concerning since research has associated ultra-processed foods with an increased risk of cancer and type 2 diabetes.

While many experts agree on the harmful effects of ultra-processed foods, there are debates about whether certain foods—including soy milk—should fall into the ultra-processed food category.

Putting plant-based beverages like soy milk in the same category as candy and soda isn’t an accurate classification, according to B. Pam Ismail, PhD, the founder and director of the Plant Protein Innovation Center and a professor of food science and nutrition at the University of Minnesota.

Soy milk falls under the category of ultra-processed foods because it has to go through a series of industrial processes, but these processing steps are necessary.

“Processing is necessary to make soy milk safe and nutritious, and it is unlike other ultra-processed foods that are often high in added sugars, unhealthy fats, and artificial additives, which can have negative health implications if consumed excessively,” Debbie Petitpain, MS, RDN, LDN, a registered dietitian based in Charleston, South Carolina, told Verywell in an email.

Both Soy and Cow’s Milk Fit Into a Balanced Diet

Choosing between soy milk and dairy milk is ultimately up to your personal preference and lifestyle.

If you’re lactose intolerant or concerned about animal welfare, you may prefer soy milk. However, cow’s milk may be the right choice if you have a soy allergy or simply enjoy the taste of dairy.

Soy milk isn’t a perfect substitute for dairy milk either, according to Ismail. “Nothing is going to replace the experience of dairy. Nothing is going to taste like cow’s milk or give you the exact nutrition or characteristics of cow’s milk,” she said.

There are also debates about the safety of phytoestrogens in soy milk and synthetic hormones (rBGH or rBST) in cow’s milk. Some are worried that phytoestrogens in soy might increase the risk of breast cancer, thyroid conditions, or dementia, although these claims haven’t been proven. Meanwhile, synthetic hormones in cow’s milk may contribute to prostate, breast, or colorectal cancers, but there is not enough evidence to suggest that these pose significant risks for humans.

“Individual preferences, dietary restrictions, and health goals should guide your choice,” Petitpain said. “The key is to prioritize variety and moderation in your diet, incorporating a mix of plant-based and animal-based foods to ensure a well-rounded intake of essential nutrients.”

What This Means For You

Both cow’s milk and fortified soy milk are good sources of calcium, protein, potassium, and magnesium. Among all the plant-based milk alternatives, soy milk is the only one that fits into the USDA’s dairy category.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Department of Agriculture: MyPlate. Dairy.

  2. Monteiro CA, Cannon G, Levy RB, et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutr. 2019;22(5):936-941. doi:10.1017/S1368980018003762

  3. Fiolet T, Srour B, Sellem L, et al. Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort. BMJ. 2018;360:k322. doi:10.1136/bmj.k322

  4. Srour B, Fezeu LK, Kesse-Guyot E, et al. Ultraprocessed food consumption and risk of type 2 diabetes among participants of the NutriNet-Santé prospective cohort. JAMA Intern Med. 2020;180(2):283. doi:10.1001/jamainternmed.2019.5942

  5. Harvard T. H. Chan School of Public Health. Straight talk about soy.

  6. American Cancer Society. Recombinant bovine growth hormone (rBGH).

  7. Food and Drug Administration. Bovine somatotropin (bST).

Stephanie Brown

Stephanie Brown

By Stephanie Brown

Brown is a nutrition writer who received her Didactic Program in Dietetics certification from the University of Tennessee at Knoxville. Previously, she worked as a nutrition educator and culinary instructor in New York City.


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