SAA1 and postmenopausal osteoporosis: As far as we know, there is only one study and it did not consider the association between SAA level and BMD [26].In contrast to our results, there are some reports in favor of the association between BMD and serum vitamin D [8, 9, 36] or hs-CRP [37] in osteoporosis, but the data are inadequate with respect to postmenopausal osteoporosis.To sum up, it is difficult to confirm the protective role of vitamin D (alone) and its immune-regulatory mechanism of action in osteoporosis and its related conditions, due to diversity in studies and contradictive results.