INS and metabolic syndrome: We observed increased levels of TG, FBG, INS, and HOMA-IR, and decreased level of HDL-C in peripheral blood of the offspring from mothers that experienced 25(OH)D deficiency during pregnancy (Figure 1), indicating that maternal 25(OH)D deficiency induced MetS in their offspring, which is consistent with the findings from Huaqi Zhang et al. (Zhong et al., 2017).