Non-dairy milks are often fortified with calcium. But does your body absorb this calcium as well (or better) than the calcium from milk?
Q. How does the absorbability of calcium-fortified soy milk or almond milk compare with the absorbability of calcium from cow's milk?
A. Milk and dairy products are naturally rich in calcium and—contrary to some false rumors circulating around the Internet—the calcium from dairy products is well absorbed by the body. Non-dairy milks, on the other hand, are not naturally high in calcium and are often fortified to bring their calcium content closer to that of cow's milk. The absorbability of the calcium from these fortified foods depends on what form of the mineral is used.
Check the ingredient list of your favorite brands. Non-dairy milk fortified with calcium carbonate appears to have absorbability equivalent to the calcium in milk—and about 33% better than non-dairy milks fortified with tricalcium phosphate. Calcium is also better absorbed when it's consumed with foods because other nutrients in those foods help with absorption.
Heaney, R.P., K. Rafferty, J. Bierman, et al. Not all calcium-fortified beverages are equal. Nutr. Today 40: 39-44, 2005.
Heaney, R.P., M.S. Dowell, et al. Bioavailability of the calcium in fortified soy imitation milk, with some observations on method. Am. J. Clin. Nutr. 71: 1166-1169, 2000.
Zhao, Y., B.R. Martin, and C.M. Weaver. Calcium bioavailability of calcium carbonate fortified soymilk is equivalent to cow’s milk in young women. J. Nutr. 135: 2379-2382, 2005.
Almond milk in jug image courtesy of Shutterstock