Objectives: To study the recently published literature on the relationship between vitamin D deficiency and insulin resistance (IR) and type-2 diabetes (T2D). Methods: We conducted a thorough search of PubMed, SCOPUS, Web of Science, and Google Scholar to find pertinent literature. Rayyan QRCI was utilized during the entire process. Results: We included ten studies with a total of 30113 patients and 12439 (41.3%) were males. The follow-up duration ranged from 0.5 year and 13.5 years. The reported vitamin D level ranged from 6.3 ng/mL to 47.9 ng/mL. This study included a variety of populations including the general population, T2D patients, and prediabetes patients. Higher levels of vitamin D may be protective against the development of diabetes. The included studies demonstrated that vitamin D deficiency is significantly associated with hyperinsulinemia, prediabetes, IR, and T2D. Conclusion: The results of this systematic analysis showed that the risk of T2D, prediabetes, and IR is markedly increased in individuals with a vitamin D deficit. More study is required, especially in those with poor glucose tolerance and/or fasting glucose, who may not be obese but are at a high risk of developing diabetes. It is necessary to do longer-term research in order to verify these results and investigate any possible pathophysiological bases.