A deficient vitamin D status has been associated with various diseases but its correlation with different types of cancer remains of interest. Thyroid cancer is the most frequent endocrine malignancy and despite the fact that differentiated thyroid carcinoma (DTC) has an excellent survival rate (>90% 10-year survival), persistent and recurrent disease is still an issue nowadays. Epidemiological studies confirmed lower levels of vitamin D in patients with DTC and correlation of 25-hydroxy vitamin D3 [25(OH)D3] status with clinicopathologic features and poor prognosis, being considered a biomarker for aggressiveness.Vitamin D, through it active form 1α,25-dihydoxyvitamin D3 [1,25(OH)2D3] and its receptor (VDR) exerts genetic changes to both healthy and neoplastic cells thus controlling their proliferation, differentiation and apoptosis. Also, vitamin D binding protein (DBP) has been recently discovered to have many different biological functions. This review is an update on molecular mechanisms of vitamin D signaling and its association with thyroid cancer prevention, treatment and prognosis.