Next, we analyzed rs671 frequency in osteoporosis and normal subjects and observed ALDH2 mutation (+) frequencies of 52.8 and 35.4%, in osteoporosis and normal groups, respectively (Fig. 3), with an odds ratio of 2.04 and a 95% confidence interval of 1.07–3.88 between osteoporosis and normal groups (Fig. 3). Here, ALDH2 is linked to osteoporosis.