Background: This study aimed to assess the effect of vitamin D insufficiency or deficiency in early pregnancy on the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) in women with gestational diabetes mellitus (GDM) and to determine the correlation between HOMA-IR and pregnancy outcomes.
Methods: General clinical data, HOMA-IR, β-Cell function index (HOMA-β), and pregnancy outcomes were retrospectively analyzed in 248 GDM patients with vitamin D insufficiency and 81 GDM patients with vitamin D deficiency from September 2019 through April 20, 2023. The correlation between vitamin D and HOMA-IR was analyzed using multiple linear regression.