Very high rates of vitamin D insufficiency in women of child-bearing age living in Beijing and Hong Kong

Jean Woo, Christopher W.K. Lam, Jason Leung, Winny Y. Lau, Edith Lau, Xu Ling, Xiaoping Xing, Xi He Zhao, C. Murray Skeaff, Catherine J. Bacon, Jennifer E.P. Rockell, Aaron Lambert, Susan J. Whiting, Tim Green

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Abstract

We aimed to describe the vitamin D status of young women living in two Chinese cities in the spring - Beijing in the north (latitude 39° north) and Hong Kong (latitude 22° north) in the south. We also examined the relationship between serum 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations to determine a threshold for serum 25-hydroxyvitamin D above which there is no further suppression of PTH. Finally, we examined whether dietary Ca intake influences this relationship. Non-pregnant women aged 18-40 years (n 441) were recruited between February and June. Fasting blood was collected and dietary intakes were assessed using 5 d food records. Mean serum 25-hydroxyvitamin D concentration was lower in Beijing than Hong Kong women (29 v. 34 nmol/l; P < 0.001). Vitamin D deficiency (≤ 25 nmol/l) was indicated in 40 % of Beijing and 18 % of Hong Kong women, and over 90 % of women in both cities were insufficient (≤ 50 nmol/l). Mean Ca and vitamin D intakes were 478 mg/d and 2.0 μg/d, respectively. The relationship between 25-hydroxyvitamin D concentration and PTH was linear throughout the range with a slope of -0.36 (different from 0; P < 0.001; R 0.26), with no apparent threshold. There was no influence of Ca intake on the relationship between 25-hydroxyvitamin D and PTH concentration. Vitamin D deficiency is common and insufficiency is very common in non-pregnant women in Hong Kong and Beijing during spring. Serum 25-hydroxyvitamin D was inversely associated with PTH with no apparent threshold. Strategies such as vitamin D fortification or supplementation may be required.

LanguageEnglish
Pages1330-1334
Number of pages5
JournalBritish Journal of Nutrition
Volume99
Issue number6
DOIs
Publication statusPublished - 7 Oct 2008

Keywords

  • 25-Hydroxyvitamin D
  • Calcium intake
  • China
  • Parathyroid hormone
  • Women

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

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