We already knew vitamin D was a superstar, but June sure was a banner month for the sunshine vitamin. Besides being linked to better blood pressure control and dropping your risk of an early death, new research finds that D could turn out to be the key to lowering your blood sugar AND your weight.

It turns out that the sunshine vitamin treatments act on the brain to improve both weight and blood glucose control in the overweight, according to an animal study presented at the joint meeting of the International Society of Endocrinology and the Endocrine Society in Chicago.

The hypothalamus, located in our brains, controls both our weight, and glucose levels. Since nature saw fit to load up our hypothalamuses with vitamin D receptors, we had a hunch that the sunshine vitamin might play an important role in these areas too.

It turns out we were right.

Researchers delivered vitamin D directly to the hypothalamus in the brains of chubby rats and what followed was rather remarkable: rats that received the sunshine vitamin had better glucose tolerance, which is how our bodies respond to sugar. And, in a second experiment, the rats in the sunshine vitamin group had greatly improved insulin sensitivity, as well. This is important, because insulin resistance can lead to full-blown diabetes.

(We've seen this connection between vitamin D and blood sugar before. Click here to read more about it on the NorthStar Nutrtionals blog.)

But the scientists weren't done with their vitamin D research. In yet another experiment, they took a look at the long-term impact of vitamin D treatment. The group of rats receiving the sunshine vitamin supplement over four weeks ate three times less food than the control rats and, amazingly, dropped 24 percent of their weight without doing a lick more exercise than normal!