No Doubt

There is no doubt that soy has a role in maintaining healthy bones and may even help to prevent bone loss in postmenopausal women. However, it is still not clear whether the benefits are due to its soy protein, or its isoflavones daidzein and genistein, or the combination of them. The best approach is to include soy foods such as tofu, tempeh, soy milk, edamame etc in your diet instead of taking isolated soy supplements. Many brands of soy milk are now fortified with calcium. Hence, one glass of fortified soy milk provides an equivalent amount of calcium from a glass of cow's milk.
With the increasing public concerns regarding genetically modified foods, look for soy products which use non-genetically modified soy crops in their production.