title: [Effect of calcium supplementation on the regain of BMD in Chinese lactating women with 4 major combined ER genotypes].
abstract: OBJECTIVE
  To observe the regain of bone mineral density (BMD) in Chinese lactating women with 4 major combined ER genotypes (defined as Pvu II and Xba I).
  
  
  METHODS
  A total of 160 healthy lactating women was selected, 40 women with each of 4 genotypes (ppxx, Ppxx, PpXX or PPXx) were divided into a calcium supplement group received 600 mg calcium (as CaCO3) daily, and a control group. BMD of lumbar spine and left hip were measured by dual energy X-ray absorption bone densitometry on 3 months and one year after delivery. Calcium intake was calculated from a 3 days dietary recall.
  
  
  RESULTS
  Whether supplementing calcium or not, the BMD of these women increased obviously (P <0.05).The less BMD regaining at hip was observed in women with ppxx genotype than those with Ppxx or PPXx genotype (P <0.05) when 600 mg calcium was given daily. Calcium supplementation and the duration of lactation were significantly related to hip BMD via a stepwise linear regression analysis (the standardized coefficient was 0.227, and P value was 0. 007).
  
  
  CONCLUSIONS
  Although the dietary calcium intake was low in Wuhan lactating women, the BMD of lumbar spine or of left hip of women with some genotypes was increased greatly by calcium supplementation.
authors.affiliation: Institute of Nutrition and Food Safety, China CDC, Beijing 100050, China. yuboshi@263.net
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Gong
authors.forename: Jing
authors.initials: J
authors.lastname: Zeng
authors.forename: Dunjin
authors.initials: D
authors.lastname: Zhou
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Yang
authors.forename: Zhenwu
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000328:Adult; D015519:Bone Density; D002118:Calcium / Q000008:administration & dosage*; D002681:China; D019587:Dietary Supplements; D005260:Female; D005838:Genotype; D006801:Humans; D007774:Lactation / Q000235:genetics* / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics*; D014886:Weaning
chemical_list: D011960:Receptors, Estrogen; D002118:Calcium