妊娠期钙代谢与补钙的作用

The Metabolism of Calcium during the Gestational Period and the Complement of Calcium

目的研究孕期母体钙代谢的特点及补钙对其影响。方法选择373例在我院行产前检查的单胎孕妇，孕20周始在正常饮食的基础上每日进食500ml牛奶或500mg柠檬酸钙，并于每晚再口服柠檬酸钙300mg至孕37周。首次产前检查及孕37周时测定血清钙离子（Ca^＋＋）、磷（P）、碱性磷酸酶（ALP）及尿钙（U—Ca）／肌酐（U—Cr）、羟脯氨酸（U—HOP）／肌酐（U—Cr）。根据首次产前检查时间将孕妇分为早孕组（≤12周），中孕组（13周～20周），服钙至37周者为晚孕组，晚孕组又按服钙情况分为按规定服钙组，未按规定服钙组，将同期到我院行孕前检查的同龄健康非孕妇女56名作为对照组进行分析。结果早孕组血清Ca^＋＋、ALP、U—HOP／U-Cr较对照组无明显改变（P〉0．05），U—Ca／U—Cr较对照组明显降低，（P〈0．05）；中孕组血清Ca^＋＋、U—Ca／U—Cr较对照组及早孕组均明显降低（P〈0．05）；血清ALP、U—HOP／U—Cr较对照组及早孕组明显增高（P〈0．05）。晚孕两组血清Ca^＋＋、U—Ca／U—Cr较对照组明显降低（P〈0．05）；血清ALP、U—HOP／U—Cr较对照组明显增高（P〈0．05），Ca^＋＋、U—Ca／U—Cr较中孕期组无明显改变（P〉0．05），血清ALP、U—HOP／U—Cr较中孕组明显增高（P〈0．01），晚孕两组Ca^＋＋、U—Ca／U—Cr、ALP、U—HOP／U—Cr无显著性变化（P〉0．05）。结论补钙应从孕中期开始，中国营养协会推荐的1200mg／日钙量是恰当的。

Objectives To study the character of the metabolism of calcium of gestational women and effect of supplying calcium for gestational women. Methods All the 373 pregnant women with single fetal were observed. They were provided calcium citrate 300mg and 500 ml milk every day, since the 20^th gestational week, and from the 37^th gestational week, the tablet of calcium citrate （300 mg） was added every evening. During the first prenatal examination and that in the 37^th week, the serum level of calcium, phosphorus, alkaline phosphatase, and the ratio between urine calcium and creatinine, and the ratio between hydroxyproline and creatinlne were measured. According to the first prenatal examination, the pregnant women were divided into three groups： the earlier one （ 〈 = 12^th week）, the middle one （13^th - 20^th week） and the later one （30^th week）; and the later group was subdivided into those who took calcium and those who didn＇t. The changes of parameters above in gestational ages were studied. Results The level of serum calcium and the ratio between urine calcium and ereatinine became lower and lower with the increase of the gestational ages. Taking calcium citrate 300mg and 500 ml milk every day could correct the parameters. Conclusions Calcium deficiency became more and more evident with increase of the gestational ages. Taking 500 ml milk and calcium citrate 300mg can interrupt the declining of serum calcium, but cannot change the rate of bone turnover. It is important to take calcium every day since the 12^th gestational week.