Supplementation with vitamin K may reduce the progression of insulin resistance in older men, according to a study reported in the November 2008 issue of Diabetes Care.

Insulin resistance reduces blood sugar control and contributes to the development of diabetes. Researchers from Tufts University in Boston, Massachusetts and their colleagues studied the effects of vitamin K supplementation for 36 months in 355 diabetic men and women ranging from 60 to 80 years of age. They found that vitamin K supplementation at doses attainable in the diet significantly reduced progression of insulin resistance in older men, but not in older women.

This trial was an ancillary study of a controlled trial that was designed to evaluate the effect of vitamin K supplementation on bone loss, so the reported findings still need to be replicated in a study that is specifically designed to test the potentially role of vitamin K in insulin resistance. However, these findings do suggest that adequate dietary intake of vitamin K may improve blood sugar status in older adults.