The Association Between Serum Ferritin and 25-Hydroxyvitamin D and Metabolic Syndrome in Korean Women: The Korea National Health and Nutrition Examination Survey 2010–2012

The study analyzed data from 9,256 Korean women over 20 years old to explore the relationship between serum ferritin, 25-hydroxyvitamin D [25(OH)D], and metabolic syndrome (MetS). It found that in the 6,960 women without MetS, there was a positive association between vitamin D and serum ferritin levels, as well as with iron-related variables, indicating a potential role of vitamin D in iron metabolism. However, this association was not present in the 2,296 women with MetS. The research also highlighted a high prevalence of vitamin D deficiency or insufficiency (77%) among the participants. The study suggested that vitamin D's influence on ferritin levels might vary depending on the presence of MetS and the type of anemia, but it acknowledged limitations such as not accounting for seasonal vitamin D variation or other factors like hepcidin levels and medication use.