Soy milk is a dairy-free alternative to cow's milk that is made from soy, according to Mayo Clinic. The plant comes from the subtropical regions of southeastern Asia.
Soy milk provides a source of dietary protein, including every essential amino acid. It also contains isoflavones, fiber, lecithin and phospholipids.
Soy milk is made from the liquid that remains after soaking, grinding and straining soy beans. As it does not contain any lactose, it is popular among those who are lactose intolerant. In addition, it is a dairy substitute for vegans. Some manufacturers offer fortified versions of soy milk to ensure it is as nutritionally sound as cow's milk. Individuals switching milk types should ensure their chosen brand contains enough of the vitamins they need.