Low Vitamin D Status Is Not Associated With Thyroid Cancer Risk

Abstract

Background: Low vitamin D status has been known to be associated with the increased prevalence and worse prognosis of several cancers. The aim of this study was to investigate the correlation between vitamin D insufficiency and the risk of malignancy of thyroid nodules and the prognosis of differentiated thyroid cancers (DTCs).

Methods: This cross-sectional study included a total of 410 patients who submitted to simultaneous measurements of serum 25-hydoxyvitamin D (25(OH)D) and ultrasonography-guided fine-needle aspiration for thyroid nodules during the period from March 2005 to June 2009. Levels of serum free thyroxine, thyroid stimulating hormone, anti-thyroid antibodies, parathyroid hormone (PTH), calcium, and phosphorus were also measured. Vitamin D insufficiency was defined as a serum 25(OH)D level < 75 nmol/L. In addition, the clinicopathologic characteristics of 34 patients who underwent thyroidectomy for DTC were analyzed retrospectively.

Results: The prevalence of vitamin D insufficiency was 40.2%. Serum 25(OH)D levels and the prevalence of vitamin D insufficiency showed no significant differences between benign (n = 366) and malignant (n = 44, 10.7%) thyroid nodules. Serum 25(OH)D levels showed a negative correlation only with serum PTH levels after adjusting for age, sex, body mass index, and sampling season. Among DTC patients, vitamin D insufficiency was not associated with disease stage or any other prognostic features.

Conclusions: Vitamin D insufficiency was not associated with the development of thyroid cancer or the prognostic characteristics of DTC.




J Endocrinol Metab. 2016;6(4):116-122
doi: http://dx.doi.org/10.14740/jem365w