Soy milk is high in protein with about 7 grams for every 8-ounce glass, so it could be a decent plant-based alternative for vegetarians. However, despite soy products generally being high in Vitamin K, which helps calcium adhere to bones, soy milk has a low concentration of it. It also contains very little calcium, Vitamin D and Vitamin E. So if you have weak bones, go for almond milk.