Prevention of osteoporosis in ovariectomized mice with calcium yak caseinate.

Moderate calcium supplementation coupled with enhanced calcium absorption rates in postmenopausal women is crucial for the prevention of postmenopausal osteoporosis (PMOP). Here, calcium yak caseinate (CYC) was provided to ovariectomized (OVX) mice as a nutrition supplement for 6 wk and was shown to effectively improve PMOP. It was observed that CYC remarkably improved the bone physical index (bone length and weight) of OVX mice, and significantly reduced the levels of serum calcium, alkaline phosphatase, and carboxy-terminal telopeptide of type I collagen, while significantly increasing the level of serum procollagen I N-terminal propeptide. It is of particular significance that low-dose CYC (L-CYC) was observed to prevent the decline of bone mineral density in OVX mice. Moreover, CYC supplementation has been shown to attenuate the deterioration of trabecular bone structure and to maintain the morphology and number of trabeculae. Additionally, it has been demonstrated to prevent skeletal muscle atrophy to a certain extent. This study indicated that L-CYC effectively inhibited bone resorption while facilitating bone formation, thereby improving bone quality in OVX mice.