Vitamin D supplemental intake is linked to a significantly lower risk of developing diabetes (6/55 vs 13/49; p = 0.04) and a higher rate of reversal to glucose levels (23/55 vs. 10/49; p = 0.02) in people with vitamin-D insufficient or deficient prediabetes. It is also linked to a decrease in resistance to insulin and inflammation throughout the body (TNFa and IL6). Diabetes development was independently predicted by baseline vitamin D and 2-hour blood glucose. Here, TNF is linked to prediabetes syndrome.