ABSTRACT
BACKGROUND:Vitamin D is a key substance that promotes calcium absorption and maintains the health of skeletal system,but its relationship with bone mineral density remains controversial.OBJECTIVE:To determine the relationship between serum level of vitamin D and bone mineral density in the middle-aged and elderly patients in southern China.METHODS:The patients aged over 50 years old admitted in the clinic and in-patient department of a large-scale 3A hospital from July 2014 to December 2016 were enrolled and the clinical data were collected.Then,the association between the serum level of 25-hydroxy vitamin D (25(OH)D) and bone mineral density (at the lumbar spine,femoral neck and total hip) was analyzed.RESULTS AND CONCLUSION:A total of 1 154 patients (77.2％ female) were enrolled with a mean age of (64.62±10.48)years,and the mean serum level of 25(OH)D was (62.07±37.40) nmol/L.The serum level of 25(OH)D decreased with age increasing,and the proportion of vitamin D insufficiency/deficiency in patients aged 50-59,60-69 and ≥ 70 years old was 71.3％,77.0％ and 80.1％,respectively.Correlation analysis showed that the serum level of 25(OH)D was not associated with bone mineral density at the lumbar spine,but had a weakly positive correlation with bone mineral density at the femoral neck and total hip (r=0.09 and 0.08,P ＜ 0.01).For patients with vitamin deficiency (25(OH)D ≤ 50 nmol/L),there was a significantly positive correlation between serum level of vitamin D and bone minerat density at the lumbar spine,femoral neck and total hip (r =0.117,0.120 and 0.146,P ＜ 0.01).After subgroup analysis,vitamin D level was not associated with bone mineral density in male,but was significantly associated with that in female (r=0.105,0.135 and 0.171 for the lumbar spine,femoral neck and total hip,respectively,P ＜ 0.01).Therefore,the prevalence of vitamin D deficiency is common in middle-aged and elderly patients in southern China.The serum level of vitamin D is not related to bone mineral density in male,but was positively correlated with that in female.