NPPB and type 2 diabetes mellitus: VDD: vitamin D deficiency, VD: vitamin D, T2DM: type 2 diabetes mellitus, FFs: fragility fractures, HbA1c: hemoglobin A1c, RCT: randomized control trial, IR: insulin resistance, BP: blood pressure, BNP: b-type natriuretic peptide, CHD: coronary heart disease, CVS: cardiovascular, PAD: peripheral artery disease, DFU: diabetic foot ulcer, GFR: glomerular filtration rate, DN: diabetic nephropathy, DPN: diabetic peripheral neuropathy.