Background:  Osteoporosis and tumour‐associated antigen (TAA) levels are associated with inflammatory processes, but little remains known about TAA levels and bone mineral density (BMD).
Aims:  We determined whether or not high‐normal TAA levels are associated with a lower BMD in healthy women.
Methods:  A total of 3769 healthy women were enrolled from the health screening programme over 5 years. Each participant had undergone a basic health examination. Serum carbohydrate antigen (CA)‐125, CA‐19‐9, carcinoembryonic antigen (CEA) and alpha‐fetoprotein levels were evaluated as tumour markers. The correlations between serum TAA levels and BMD were analysed.
Results:  Carbohydrate antigen 125 and CEA levels were positively associated with a higher BMD in the pre‐menopause. In the post‐menopause, the CA‐125 level was positively associated with BMD. In the pre‐menopause, CA‐125 (r = 0.102; P < 0.001) and CEA levels (r = 0.134; P < 0.001) had a significant correlation with BMD. In the post‐menopause, CA‐125 was negatively associated with alkaline phosphatase (r = −0.298; P < 0.001). Conclusions:  There was a significant positive association between CA‐125 and BMD in healthy women. Additional basic and clinical studies on the relationship between CA‐125 and bone are needed.