Abstract: Recent studies have revealed that obease increases the risk of differentated thyroid carcinoma (DTC); iodine increases the risk of papillary thyroid carcinoma wheras decreases the risk of follicular thyroid carcinoma; vitamin D decreases the risk of DTC, but there are not enough evidences to prove that vitamin A, C and E can decrease the risk of DTC; alcohol may decrease the risk of DTC, but the mechanism is still unknown; xenobiotics increases the risk of DTC. It is essential for DTC prevention to clarify the protection and risk factors.

Key words: Thyriod neoplasms, Dietary