Objective To investigate the effects of calcitriol combined with zoledronic acid on glycometabolism and serum bone-specific alkaline phosphatase(BALP)and C-terminal telopeptide of type Ⅰ collagen(CTX)in elderly patients with diabetes mellitus and osteoporosis.Methods A total of 80 patients with type 2 diabetes mellitus and osteoporosis admitted to Department of Endocrine,The Second People's Hospital of Liaocheng from January 2021 to June 2023 were selected as research subjects.There were 38 males and 42 females.They were randomly divided into observation group and control group,with 40 cases in each group.The observation group was treated with calcitriol combined with zoledronic acid,and the control group was treated with zoledronic acid alone.Moreover,the patients in both groups were orally given 0.75 g of vitamin D calcium chewable tablets twice a day for 6 consecutive months.The efficacy,bone mineral density,fasting blood glucose(FPG),2 h postprandial blood glucose(2hPG),glycosylated hemoglobin(HbA1c),serum BALP and CTX were compared between the two groups.Results After 6 months of treatment,there were no significant differences in the FBG,2hPG or HbA1c between the observation group and control group([8.04±0.66]mmol/L vs.[8.17±0.67]mmol/L,[12.18±0.91]mmol/L vs.[12.44±0.79]mmol/L,8.39%±0.69%vs.8.54%±0.62%,P>0.05).After 6 months of treatment,the bone mineral densities at left femoral trochanter,right forearm,right femoral neck,and lumbar spine in the observation group were significantly higher than those in the control group([0.86±0.14]g/cm3 vs.[0.74±0.12]g/cm3,[0.76±0.11]g/cm3 vs.[0.69±0.13]g/cm3,[0.78±0.13]g/cm3 vs.[0.71±0.14]g/cm3,[0.77±0.12]g/cm3 vs.[0.71±0.08]g/cm3,P<0.05).After 6 months of treatment,the levels of CTX and B-ALP in the observation group were significantly lower than those in the control group([0.047±0.09]ng/ml vs.[0.556±0.15]ng/ml,[11.58±2.21]U/L vs.[14.94±2.25]U/L,P<0.05).The overall effective rate in the observation group was 97.50%,which was higher than that in the control group(82.50%,P<0.005).There was no significant difference in the incidence of adverse reactions between the two groups(P>0.05).Conclusion Combined treatment with calcitriol and zoledronic acid can improve bone mineral density,regulate bone metabolism,and alleviate the symptoms of osteoporosis in elderly patients with diabetes mellitus and osteoporosis,without adverse effect on glucose control.