Milk’s Calcium Better Absorbed than Soy

May 2, 2000

A new study published in the American Journal of Clinical Nutrition finds that calcium from cow’s milk was more efficiently absorbed by the adult men in the study than calcium from soy beverages. Soy beverages naturally contain very little calcium so manufacturers often fortify the beverages with calcium.

"Our findings show that calcium fortification of soy beverages usually fails to produce a calcium source comparable to cow’s milk in terms of physical properties or absorbability," said co-author Robert P. Heaney, professor of medicine at Creighton University. "Even if a label indicates the two beverages have the same calcium per serving, the bioavailability or the amount of calcium absorbed from the soy beverage will be significantly less – typically 25% less absorbed compared to cow’s milk."

The researchers noted that while it is possible for soy beverage manufacturers to add enough calcium to achieve a comparable absorption level as cow’s milk, the reality is that not all brands do. According to this research, 60% more calcium is needed in soy beverages for soy to be comparable to cow’s milk.