title: Vitamin D status and its association with parathyroid hormone concentrations in women of child-bearing age living in Jakarta and Kuala Lumpur.
abstract: OBJECTIVE
  To describe the vitamin D status of women living in two Asian cities,--Jakarta (6 degrees S) and Kuala-Lumpur (2 degrees N), to examine the association between plasma 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations, and to determine a threshold for plasma 25-hydroxyvitamin D above which there is no further suppression of PTH. Also, to determine whether dietary calcium intake influences the relationship between PTH and 25-hydroxyvitamin D.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Jakarta, Indonesia and Kuala Lumpur, Malaysia.
  
  
  METHODS
  A convenience sample of 504 non-pregnant women 18-40 years.
  
  
  METHODS
  Plasma 25-hydroxyvitamin D and PTH.
  
  
  RESULTS
  The mean 25-hydroxyvitamin D concentration was 48 nmol/l. Less than 1% of women had a 25-hydroxyvitamin D concentration indicative of vitamin D deficiency (<17.5 nmol/l); whereas, over 60% of women had a 25-hydroxyvitamin D concentration indicative of insufficiency (<50 nmol/l). We estimate that 52 nmol/l was the threshold concentration for plasma 25-hydroxyvitamin D above which no further suppression of PTH occurred. Below and above this concentration the slopes of the regression lines were -0.18 (different from 0; P=0.003) and -0.01 (P=0.775), respectively. The relation between vitamin D status and parathyroid hormone concentration did not differ between women with low, medium or high calcium intakes (P=0.611); however, even in the highest tertile of calcium intake, mean calcium intake was only 657 mg/d.
  
  
  CONCLUSIONS
  On the basis of maximal suppression of PTH we estimate an optimal 25-hydroxyvitamin D concentration of approximately 50 nmol/l. Many women had a 25-hydroxyvitamin D below this concentration and may benefit from improved vitamin D status.
authors.affiliation: Department of Human Nutrition, University of Otago, Dunedin, New Zealand.
authors.forename: T J
authors.initials: TJ
authors.lastname: Green
authors.forename: C M
authors.initials: CM
authors.lastname: Skeaff
authors.forename: J E P
authors.initials: JE
authors.lastname: Rockell
authors.forename: B J
authors.initials: BJ
authors.lastname: Venn
authors.forename: A
authors.initials: A
authors.lastname: Lambert
authors.forename: J
authors.initials: J
authors.lastname: Todd
authors.forename: G L
authors.initials: GL
authors.lastname: Khor
authors.forename: S P
authors.initials: SP
authors.lastname: Loh
authors.forename: S
authors.initials: S
authors.lastname: Muslimatun
authors.forename: R
authors.initials: R
authors.lastname: Agustina
authors.forename: S J
authors.initials: SJ
authors.lastname: Whiting
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007214:Indonesia; D008296:Malaysia; D009752:Nutritional Status; D010281:Parathyroid Hormone / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000503:physiopathology*; D016387:Women's Health
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D