Vitamin D status and its association with parathyroid hormone concentrations in women of child-bearing age living in Jakarta and Kuala Lumpur

Eur J Clin Nutr. 2008 Mar;62(3):373-8. doi: 10.1038/sj.ejcn.1602696. Epub 2007 Mar 7.

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.

Design: Cross-sectional.

Setting: Jakarta, Indonesia and Kuala Lumpur, Malaysia.

Participants: A convenience sample of 504 non-pregnant women 18-40 years.

Main measures: 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.

Conclusion: 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.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cross-Sectional Studies
  • Female
  • Humans
  • Indonesia
  • Malaysia
  • Nutritional Status*
  • Parathyroid Hormone / blood*
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood*
  • Vitamin D Deficiency / blood*
  • Vitamin D Deficiency / physiopathology*
  • Women's Health

Substances

  • Parathyroid Hormone
  • Vitamin D
  • 25-hydroxyvitamin D