目的 探讨年龄、性别、孕期母亲补钙、佝偻病早期症状与骨密度Z值的关系，为更好地预防儿童佝偻病和低骨密度工作提供依据和建议。 方法 对南京市秦淮区妇幼保健所儿保门诊的2504例0～3岁婴幼儿，用定量超声骨密度仪对其骨密度进行检测，分析骨密度不足检出率与年龄、性别、孕期补钙情况、佝偻病早期症状之间的关系。 结果 0～3岁女童骨密度Z值总体低于男童（P＜0.001）。在0～3月，3～6月，6月～1岁3个年龄段中，女童骨密度不足的发生率均明显高于男童（P＜0.001）。1～3岁年龄段中，男女童骨密度不足检出率差异无统计学意义（P＞0.05）。3～6月年龄段的婴儿骨密度不足检出率最高，达83.5%，其中女童骨密度不足检出率占该年龄总案例的51.0%。佝偻病早期症状与骨密度不足检出率差异有统计学意义（P＜0.001）。母亲孕期补钙与骨密度不足检出率差异无统计学意义（P＞0.05）。 结论 要定期监测婴幼儿骨密度，关注1岁以内小儿的骨密度，尤其关注女童。

Objective To investigate the relationship between age, gender, calcium supplementation during pregnancy, early symptoms of rickets and Z value of bone mineral density, and to provide evidence and recommendations for better prevention of rickets and low bone density in children. Methods Two thousand five hundred and four cases of infants aged 0-3 years old in the Qinhuai District Maternal and Child Health Hospital of Nanjing were tested with quantitative ultrasound bone density. The detection rate of bone mineral density was analyzed and age, sex, calcium supplementation during pregnancy and early stage of rickets. The relationship between symptoms. Results The bone mineral density Z value of girls aged 0-3 was lower than that of boys (P<0.001). In the 0-3 months, 3-6 mohth, 6 months-1 year groups, the incidence of under-bone density was significantly higher in girls than in boys (P<0.001). There was no significant difference in the detection rate of bone mineral density between boys and girls in the 1-3 years group (P>0.05). In the 3-6 months, the detection rate of infant bone mineral density was the highest, reaching 83.5%. The detection rate of girls with insufficient bone mineral density accounted for 51.0% of the total case of this age. There was a statistically significant difference in the detection rate of early symptoms and insufficient bone mineral density (P<0.001). There was no significant difference in the detection rate of calcium supplementation and bone mineral density during pregnancy (P>0.05). Conclusion It is necessary to regularly monitor the bone mineral density of infants and children, and pay attention to the bone mineral density of children within 1 year old, especially to girls.