Investigating the relationship between 25-hydroxyvitamin D and thyroid function in second-trimester pregnant women

Abstract

This study aims to explore the correlation between serum 25-hydroxyvitamin D and thyroid hormones during the second trimester. In total, 277 pregnant women at 13–28 weeks of gestation were enrolled. According to the level of thyrotropic-stimulating hormone, they were divided into a reduced TSH group, a normal TSH group and an elevated TSH group. In this study, we found that the prevalence of vitamin D deficiency was as high as 94.58%. The 25-hydroxyvitamin D level in the reduced TSH group was lower than that in the normal thyroid function group (p = .0005), and the 25-hydroxyvitamin D level in the elevated TSH group was higher than that in normal TSH group (p=.0339). A positive correlation was observed between 25-hydroxyvitamin D and thyrotropic-stimulating hormone (r = 0.3034, p = .0000). Furthermore, 25-hydroxyvitamin D was negatively correlated with the free thyroxine level (r = −0.1286, p = .0323) as well as the free triiodothyronine level (r = 0.1247, p = .0380). These data suggest that the relationships between 25-hydroxyvitamin D and thyroid parameters were characterized during the second trimester. Pregnant women in the second-trimester who are diagnosed with transient hyperthyroidism should be evaluated for the possibility of vitamin D deficiency.

Chinese abstract

本研究旨在探索妊娠中期血清25-羟维生素D与甲状腺激素的关系。共招募277名孕13-28周女性。根据促甲状腺激素（TSH）水平, 将受试者分为TSH降低组, TSH正常组和TSH升高组。本研究中, 我们发现维生素D缺乏高达94.58%。TSH降低组中25-羟维生素D水平显著低于甲状腺功能正常组（p=.0005）, TSH升高组25-羟维生素D水平高于TSH正常组（p=.0339）。25-羟维生素D与促甲状腺素间观察到正相关（r = 0.3034, p=.0000）。此外, 25-羟维生素D与游离甲状腺素水平（r= -0.1286, p=.0323）和游离三碘甲状腺原氨酸水平（r = 0.1247, p=.0380）呈负相关。这些数据表明妊娠中期25-羟维生素D与甲状腺参数之间的关系具有特点。妊娠中期被诊断为暂时性甲状腺功能亢进的孕妇应评估维生素D缺乏的可能性。

Keywords:

• 5-Hydroxyvitamin D
• thyroid function
• second trimester

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by 2016 annual Suzhou key clinical disease diagnosis and treatment technology of special project (No. LCZX201620), Jiangsu University clinical medicine science and Technology Development Fund (No. JLY20160063), and Jiangsu Province Maternal and child health research project (No. F201720).