GPT and metabolic syndrome: In women without MetS, in terms of serum ferritin levels by vitamin D after adjusting for related variables (smoking, alcohol drinking, regular exercise, current menstruation, hormonal contraceptives, hormone-replacement therapy, SBP, DBP, BMI, WM, TC, TGs, HDL-C, FPG, AST, ALT, and age), serum ferritin levels (Means ± SE) were 37.75 ± 1.31 μg/L (95% CI, 35.19–40.31) for vitamin D deficiency, 43.12 ± 0.49 μg/L (95% CI, 42.16–44.09) for vitamin D insufficiency, and 46.81 ± 0.89 μg/L (95% CI, 45.08–48.55) for vitamin D sufficiency.