High prevalence of vitamin D deficiency in Shenzhen pregnant women

Abstract

Background

Vitamin D deficiency is a public health problem worldwide. Vitamin D deficiency in pregnant women often leads to negative clinical consequence and has been distributed differently in certain latitudes. Here, we aimed to determine the prevalence of vitamin D deficiency in pregnant women in Shenzhen City and investigate the influencing factors.

Methods

A total of 27,166 healthy pregnant women, undergoing prenatal examinations in our hospital between July 2014 and December 2018, were enrolled in our study. Maternal characteristics, including the duration of pregnancy, age and enrollment time, were recorded. The concentrations of serum 25(OH)D in the blood samples were detected by immunochemistry assays.

Results

For the total study population, the median serum 25(OH)D concentration was 23.36 [17.98–29.51] ng/mL, and 34.3% and 42.4% of the participants exhibited vitamin D deficiency (serum 25(OH) D < 20 ng/mL) and insufficiency (serum 25(OH)D 21–29 ng/mL), respectively. Vitamin D deficiency decreased with gestation (37.83%, 33.8%, and 29.3% for the first trimester, second trimester and third trimester, respectively, p < .001) and decreased by age (36.03%, 35.20%, 31.86% and 29.83%, for the age groups 18–24, 25–29, 30–34 and 35–46 years, respectively, p < .001). This prevalence had conspicuous seasonality (winter vs. autumn, OR 3.69, 95% CI: 3.42–3.99, p < .001). Temperature was positively associated with women’s serum 25(OH)D level (r = 0.48, p < .001).

Conclusions

Overall, we demonstrated that vitamin D deficiency in pregnant women in Shenzhen was common and was affected by gestation, age and season/temperature.

Keywords:

• Vitamin D
• deficiency
• Shenzhen
• pregnant women

Acknowledgements

We would like to thank the staff in the Department of Clinical Laboratory in our hospital for collecting the samples.

Ethics approval

This is an observational study. The Ethics Committee of Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine has confirmed that no ethical approval is required.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Authors’ contribution

HL Liu: Project development, Data collection; JK Du: Protocol development; R Chen: Protocol development; LJ Zhao: Data analysis, manuscript writing; BT Nong: Data analysis; YH Dou: Data management; ZK Xu: Data collection; YX Li: Data collection; CF Ma: Data collection.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This study was supported by Science and Technology Planning Project of Guangdong Province, China [NO:2017A020213036] and the Shenzhen Bao’an Science and Technique Project [NO:2018JD111, 2020JD304, 2015188].