Low Vitamin D levels are associated with type 2 diabetes risk, according to a study published in Diabetes Care. Scientists from the University of Melbourne in Australia found that people with lower than average Vitamin D levels had a 57% higher chance of developing diabetes than people with Vitamin D levels.

Researchers measured Vitamin D levels in over 3,000 people without diabetes. After five years, researchers measured Vitamin D levels again and determined that 200 of the participants had developed diabetes. They found that 6 in 100 people with low Vitamin D levels developed diabetes, versus 3 in 100 with regular levels that developed diabetes. When they factored in diabetes risk factors, the risk of diabetes increased to 57%.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5456387/