Carter L M, Whiting S J, Drinkwater D T, Zello G A, Faulkner R A, Bailey D A
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada.
J Am Coll Nutr. 2001 Oct;20(5):502-9. doi: 10.1080/07315724.2001.10719059.
We examined the relationship between self-reported calcium (Ca) intake and bone mineral content (BMC) in children and adolescents. We hypothesized that an expression of Ca adjusted for energy intake (EI), i.e., Ca density, would be a better predictor of BMC than unadjusted Ca because of underreporting of EI.
Data were obtained on dietary intakes (repeated 24-hour recalls) and BMC (by DEXA) in a cross-section of 227 children aged 8 to 17 years. Bivariate and multivariate analyses were used to examine the relationship between Ca. Ca density, and the dependent variables total body BMC and lumbar spine BMC. Covariates included were height, weight, bone area. maturity age, activity score and EI.
Reported EI compared to estimated basal metabolic rate suggested underreporting of EI. Total body and lumbar spine BMC were significantly associated with EI, but not Ca or Ca density, in bivariate analyses. After controlling for size and maturity, multiple linear regression analysis revealed unadjusted Ca to be a predictor of BMC in males in the total body (p = 0.08) and lumbar spine (p = 0.01)). Unadjusted Ca was not a predictor of BMC at either site in females. Ca density was not a better predictor of BMC at either site in males or females.
The relationship observed in male adolescents in this study between Ca intake and BMC is similar to that seen in clinical trials. Ca density did not enable us to see a relationship between Ca intake and BMC in females, which may reflect systematic reporting errors or that diet is not a limiting factor in this group of healthy adolescents.
我们研究了儿童和青少年自我报告的钙摄入量与骨矿物质含量（BMC）之间的关系。我们假设，由于能量摄入（EI）报告不足，经能量摄入调整后的钙表达（即钙密度）比未调整的钙更能预测BMC。
获取了227名8至17岁儿童横断面的饮食摄入量（重复24小时回忆法）和BMC（通过双能X线吸收法）数据。采用双变量和多变量分析来研究钙、钙密度与因变量全身BMC和腰椎BMC之间的关系。纳入的协变量包括身高、体重、骨面积、成熟年龄、活动评分和EI。
报告的EI与估计的基础代谢率相比表明存在EI报告不足。在双变量分析中，全身和腰椎BMC与EI显著相关，但与钙或钙密度无关。在控制了体型和成熟度后，多元线性回归分析显示，未调整的钙是男性全身（p = 0.08）和腰椎（p = 0.01）BMC的预测指标。未调整的钙在女性的任何一个部位都不是BMC的预测指标。钙密度在男性或女性的任何一个部位都不是BMC的更好预测指标。
本研究中在男性青少年中观察到的钙摄入量与BMC之间的关系与临床试验中所见相似。钙密度未能使我们发现女性钙摄入量与BMC之间的关系，这可能反映了系统性报告误差，或者饮食不是这组健康青少年的限制因素。
