Forget Big Pharma's dangerous roster of expensive antidepressant drugs... because the real answer to some cases of the blues might be staring down at you right now.

A new study finds that seniors might be able to lower their risk of depression by simply spending a little more time in the company of our warmest neighbor: the sun.

Researchers looked at vitamin D levels in 531 women and 423 men, all 65 years old or older. Then, over six years, they tracked those D levels along with symptoms of depression.

The researchers found that those with the lowest levels of the sunshine vitamin had the highest risk of depression-- especially women.

The joint study between U.S. and Italian researchers published in the Journal of Clinical Endocrinology & Metabolism isn't conclusive, since it was observational... but it's one more log in a growing fire, because vitamin D deficiencies have been linked to depression in the past.

One 2008 study found that low levels of D combined with higher levels of the parathyroid hormone appeared to increase the risk of depression in people between the ages of 65 and 95 years old.

Other studies have made similar connections--and not only among seniors. Just look at the millions of people who've felt the winter blues, or seasonal affective disorder. It's no coincidence this condition hits when sun exposure is at its lowest and people are even more likely to suffer from deficiencies in D.

The cutoff point in the latest study was 50 nanomoles per liter of D in the blood--anything below that appeared to increase the depression risk. But even those levels are really much lower than what you should have.

And the sad reality is, most people are in that category.

I've written to you before about our collective D crisis, as well as all the other amazing benefits of this one simple hormone. (Read, "Vitamin D miracles keep mounting.") Vitamin D can help with everything from bone health to longer lives, and lower your risk for everything from diabetes to heart disease.

A doctor can check your D levels--but even those tests aren't failsafe. There's no single standard for vitamin D tests, and last year one of the nation's biggest laboratories--Quest Diagnostics--admitted that it had been botching D tests for two years.

As a result, many people with D deficiencies were actually told they had high levels.

There's a simple answer, and it's right above you: Get outside a little more and soak up some sun. No one needs to turn into a beach bunny, but a few minutes of direct sunlight a day can help your body make its own D, for free.

But since even sun quality can vary, and most people simply don't get out enough, add a supplement just to make sure you're covered.