CORRELATION BETWEEN THYROID STIMULATING HORMONE AND VITAMIN D IN EUTHYROID SUBJECTS

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 238-262-Vitamin D Action, Deficiency & Disorders
Bench to Bedside
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-251
Dong Yeob Shin*1, Kwang Joon Kim2, Hyeonjin Park1, Kyeong Hye Park1, Sena Hwang1 and Eun Jig Lee1
1Yonsei University College of Medicine, Seoul, South Korea, 2Severance Hospital, Seoul, South Korea
Objective: It is known that vitamin D is associated with the level of thyroid stimulating hormone (TSH) in hypothyroid patients. Recently, however, it has been suggested that thyroid function may actually be suppressed even with TSH being within normal euthyroid range, if TSH is greater than 2.5 mIU/L. Therefore, we investigated the correlation between vitamin D and TSH in euthyroid population.

 Methods: This was a retrospective, cross-sectional study analyzing the data of 442 patients whose serum 25(OH)D3 level was measured in euthyroid state. Thyroid ultrasonography, measurement of thyroid autoantibody (TPOAb, thyroglobulin Ab), and thyroid function test (TFT) was performed while simultaneous measuring serum 25(OH)D. Patients were excluded if diffuse thyroiditis was suspected on ultrasonography or if positive for thyroid autoantibodies.

 Results: After dividing the patients into two groups- TSH level greater or less than 2.5 mIU/L, the mean level of serum 25(OH)D3 was higher in patients with TSH less than 2.5 mIU/L (21.3 vs 15.2 mIU/L, p-value <0.05). Also, the level of 25(OH)D3 was negatively associated with TSH (r=-0.278, p value < 0.01). After setting TSH as a dependent variable and adjusting for age, gender, BMI, and free T4, 25(OH)D3 still maintained a negative association with TSH (β = -0.223, p-value <0.05).

 Conclusions: 25(OH)D3 and TSH was negatively correlated even in euthyroid population. This implies that 25(OH)D3, as a modulator of autoimmunity, is capable of influencing thyroid function in subjects without thyroiditis.

Nothing to Disclose: DYS, KJK, HP, KHP, SH, EJL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm