Milk Myth: Soy Milk is Nutritionally Equal to Cow’s Milk

Myth: Soy Milk is a Good Alternative to Milk

Milk Myth

Myth Buster: Soy-based beverages are not nutritionally equivalent to milk.

Some people choose soy beverages as an alternative to cow’s milk for a variety of reasons, for example if they are vegan (consume no animal products whatsoever), lactose intolerant or if they perceive soy milk as healthier. What is not commonly known, however, is that soy beverages contain a very different set of nutrients than cow’s milk. Although the protein and fat content are similar, soy beverages are naturally low in calcium, containing only about 10 mg per serving. Manufacturers often fortify with calcium, though it is not required, but the amount added is not regulated and can vary from 80 to 500 mg per serving. In addition, the absorption of the calcium from soy beverages may not consistently be as high as from cow’s milk.1

The other nutrients in milk important for bone health—including vitamin D, phosphorus, potassium and magnesium—are also not present at the same levels in soy beverages. 

Thus, while soy beverages can be consumed as part of a healthy diet, they should not be considered a substitute to the nutrients obtained from cow’s milk. In fact, milk has an irreplaceable package of nutrients that cannot be found in any other single food or beverage. 

If you choose to drink soy beverages, check the labels carefully for nutrient content! For people with lactose intolerance, try lactose-free milk—since it includes the nine essential nutrients found in regular milk.

Back  |  Next Myth

1Heaney R et al. Am J Clin Nutr 2000 May; 71(5): 1166-9.
2Anderson JW, Bush HM. J Am Coll Nutr. 2011 Apr;30(2):79-91.
3Sacks F et al. Circulation 2006;113 (7): 1034–1044.