严格膳食干预下不同钙摄入量对中国健康成年人机体代谢的影响

Effects of different calcium intakes on metabolism in healthy adults under strict dietary intervention

目的探讨严格膳食干预下不同钙摄入量对中国健康成年人机体代谢的影响。方法于2015年9—10月,在哈尔滨医科大学公共卫生学院招募64名大学生(男、女性均为32名),采用双盲、随机、对照的试验设计,对研究对象进行持续35 d的膳食干预研究。将64名对象随机分为补钙组和对照组,每天给予相同的饮食,同时分别给予补钙组和对照组400 mg/d的钙补充剂和安慰剂,并在干预研究的第1、3、5周采集血液和尿液样本,检测血液中钙代谢相关激素[甲状旁腺素和1,25(OH)2D3]、生化指标及其代谢产物。采用主成分分析和偏最小二乘判别分析比较两组对象血液和尿液样本中代谢产物的差异,采用重复测量方差分析比较两组对象钙代谢相关激素和生化指标的差异。结果64名对象的年龄为23~28岁,男、女性均为32名;干预前补钙组和对照组的基线特征均衡。补钙组和对照组的血液和尿液中的代谢产物、钙代谢相关激素[甲状旁腺素、1,25(OH)2D3]水平和生化指标(血清钙、血清磷、糖脂代谢和肝肾功能指标)的差异均无统计学意义(P值均>0.05)。结论中国健康成年人300~400 mg/d的钙摄入量短期内不会导致机体产生钙缺乏所致的健康危害。

Objective To explore the effect of different calcium intakes on metabolism in healthy adults with traditional Chinese dietary pattern.Methods A total of 64 college students(32 males and 32 females)were recruited from the School of Public Health,Harbin Medical University from September to October 2015.A prospective,randomized,double-blind,placebo-controlled trial design(RCT trial)was used to strictly control the diet of the volunteers through meal preparation,so that the background of the experimental and the control group was exactly the same.In our study,64 healthy adults were randomly divided into two groups(calcium supplementation and control).The two groups were given the same diet every day.One group was given 400 mg/d of calcium supplementation,which was close to the recommended intake in China(800 mg/d);the other group was given pacebo,the average calcium intake was close to the average intake of Chinese(400 mg/d),calcium intervention lasted for 35 days.Serum and urine samples from pre-intervention,mid-intervention,and post-intervention were collected for metabolomics studies and detection of serum hormone levels and biochemical indicators.PCA and PLS-DA were used to compare the differences in serum and urine metabolites.After adjusting for age and BMI,the differences of hormones[parathyroid hormone,1,25(OH)2D3]and biochemical indicators were compared by repeated measurement variance analysis.Results The 64 subjects were aged 23-28 years,including 32 males and 32 females.The baseline characteristics of the calcium supplementation group and the control group were balanced.The results showed that there were no significant differences in blood and urine metabolites,metabolic hormone[parathyroid hormone,1,25(OH)2D3]levels and biochemical indicators(serum Ca,serum P,glycolipid metabolism and hepatorenal function indicators)between the calcium supplementation group and control group at each time point throughout the trail(P>0.05).Conclusion No health hazards associated with calcium deficiency was observed in healthy adults in the short term at current calcium intake level(300-400 mg/d).