Cumulative evidence has suggested that vitamin D deficiency is related with an increased susceptibility to various types of cancers. However, the association between vitamin D and thyroid cancer (TC) has remained to be unknown. Thus, there has been an urgent need for a meta-analysis to summarize existing evidence on vitamin D levels and the risk of TC.
This meta-analysis aimed to figure out the association between vitamin D level and the risk of TC.
A systematic search was performed for eligible articles on the association between vitamin D and TC based on PubMed, Embase, Web of Science, Cochrane, and
Results of the meta-analysis revealed lower levels of vitamin D in TC cases comparing with those in control [SMD = −0.25, 95% CI: (−0.38, −0.12); RoM = 0.87, 95% CI: (0.81, 0.94)] and the levels of 1,25 (OH)D in cases with TC were also lower than controls [SMD = −0.49, 95% CI: (−0.80, −0.19); RoM = 0.90, 95% CI: (0.85, 0.96)]. And vitamin D deficiency was associated with the increased risk of TC [OR = 1.49, 95% CI: (1.23, 1.80)]. Additionally, results from the dose-response meta-analysis showed that there is a 6% increase in the risk of TC for each 10 ng/ml decrease in 25 (OH)D levels [OR = 0.94; 95% CI: (0.89, 0.99)].
Individuals with TC had lower levels of vitamin D compared to controls, and vitamin D deficiency was correlated with an increase risk of TC.