Vitamin K may have anti-diabetes benefits: Study

Supplementing with vitamin K1 inhibits the development of insulin resistance in older men, cutting the risk of developing diabetes according to the results of a newly published 36-month, randomised, double-blind placebo-controlled study. Oddly, the effects were not observed in women, according to the researchers from the Jean Mayer USDA Human Nutrition Research Centre at Tufts University. According to the scientist the women’s weight might be influencing the effects of vitamin K decreasing its benefits. "In our study, there was a higher prevalence of obese or overweight women in the vitamin K supplementation group compared to the male supplementation group," said Dr. Booth, the lead researcher. "Vitamin K is stored in fat tissue. If there is excess fat, vitamin K may not be readily available to cells that require it to process glucose."  
The researchers recruited 355 non-diabetic men and women between the ages of 60 and 80 and 60% of the participants were women. The participants were randomly assigned to receive a daily vitamin K1 supplement (500 micrograms per day) or placebo for 36 months. The vitamin K doses is approximately five times the adequate intake, said the researchers. All of the participants also received a calcium and vitamin D supplement.
Booth and her co-workers report that insulin resistance, assessed using the homeostasis model (HOMA-IR), improved in men consuming the vitamin K supplements. Progression of insulin resistance continued in the men in the placebo group. The study is published in the November 2008 issue of the journal Diabetes Care.

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