植酸这个题目非常迷惑人，用理论推导得出的结果有时与实践不符。至于为啥植酸防骨质疏松，没研究，只好抄一段

How Do Phytate-Rich Foods Strengthen Bones?

It appears that when your diet is high in phytates, your body adjusts by decreasing the amount of calcium that gets excreted in the urine. In other words, your body conserves calcium to make up for reduced absorption from foods. Phytic acid also appears to block the formation of osteoclasts, which are cells that break down bone tissue. This, by the way, is exactly how osteoporosis drugs like Fosamax work. 

- See more at: http://www.quickanddirtytips.com/health-fitness/medical-conditions/does-phytic-acid-increase-bone-loss#sthash.wSk0XyBb.dpuf