"Use of vitamin D3 alone or in combination with vitamin K2 could be a good therapeutic strategy to simultaneously improve glucose homeostasis and bone health in patients with diabetes." according to a 2020 study conducted thru the University of Guadalajara.
"The individual and synergic effects of vitamins D and K (when taken together) could increase insulin sensitivity, osteocalcin carboxylation, and improve overall bone and glucose homeostasis," the study concluded.
Source: https://dmsjournal.biomedcentral.com/articles/10.1186/s13098-020-00580-w
Aguayo-Ruiz, J.I., García-Cobián, T.A., Pascoe-González, S. et al. Effect of supplementation with vitamins D3 and K2 on undercarboxylated osteocalcin and insulin serum levels in patients with type 2 diabetes mellitus: a randomized, double-blind, clinical trial. Diabetol Metab Syndr 12, 73 (2020). https://doi.org/10.1186/s13098-020-00580-w