title: High prevalence of vitamin D insufficiency in pregnant women working indoors and residing in Guiyang, China.
abstract: OBJECTIVE
  To assess the status of 25-hydroxyvitamin D [25(OH)D] in pregnant women in their second and third trimesters, who reside and work indoors in Guiyang, China.
  
  
  METHODS
  A total of 311 pregnant women in their 12th to 40th gestational week were engaged in employment located indoors in the urban area of Guiyang and completed a questionnaire on living habits. Levels of serum 25(OH)D were measured from fasting venous blood by liquid chromatography-mass spectrometry (LC-MS/MS). Levels of 25(OH)D were classified as vitamin D deficient [25(OH)D<20 ng/ml], insufficient [20 ng/ml≤25(OH)D<30 ng/ml], or sufficient [25(OH)D≥30 ng/ml].
  
  
  RESULTS
  The mean serum level of 25(OH)D was 14.69±6.81 ng/ml. Vitamin D deficiency, insufficiency and sufficiency were found in 260 (83.6%), 39 (12.5%), and 12 (3.9%) women, respectively. The mean level of 25(OH)D in the third trimester was significantly higher than in the second trimester (p<0.001). The mean 25(OH)D level in summer (June, July, August) was significantly higher than in the other seasons (p<0.001). The 25(OH)D level in pregnant women compliant with pre-natal calcium or multivitamin supplements was higher than in those not taking supplements (p<0.001).
  
  
  CONCLUSIONS
  These results suggest that pregnant women residing in Guiyang urban area and working indoors are at high risk of vitamin D insufficiency, particularly during spring, winter, and autumn, regardless of use of pre-natal calcium and multivitamins. Appropriate vitamin D supplementation is necessary to improve maternal vitamin D nutrition.
authors: Department of Endocrinology, The Second People's Hospital of Guiyang, Guiyang 550005, China. 5833125@163.com
authors: F
authors: F
authors: Xiang
authors: J
authors: J
authors: Jiang
authors: H
authors: H
authors: Li
authors: J
authors: J
authors: Yuan
authors: R
authors: R
authors: Yang
authors: Q
authors: Q
authors: Wang
authors: Y
authors: Y
authors: Zhang
mesh_terms: D000328:Adult; D002118:Calcium / Q000008:administration & dosage / Q000097:blood; D002681:China / Q000453:epidemiology; D019587:Dietary Supplements; D004651:Employment; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011262:Pregnancy Trimester, Second / Q000097:blood; D011263:Pregnancy Trimester, Third / Q000097:blood; D015995:Prevalence; D012621:Seasons; D053719:Tandem Mass Spectrometry; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*; D014815:Vitamins / Q000008:administration & dosage
chemical_list: D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium