Solar power isn't just a smart move in the home. It's a smart move for your head, too.

So step outside and power up your brain. Research shows that a proper amount of the sunshine vitamin (that's D, for short) in your system may help you think faster.

D for deduction
In a study of older European men, those with low levels of vitamin D in their blood did worse on a mental processing test that required quick thinking. Researchers aren't sure how vitamin D helps the brain to process information, but they think that it might help certain neuroprotective pathways. Here's another vitamin that can help your brain.

Sun smarts
Of course, in this era of ever-growing skin cancer rates, you still want to be smart about the sun, so don't overdo it. Most people can get enough vitamin D with about 10 or 15 minutes of sun exposure twice a week without sunscreen. Or find some vitamin D food sources and skip the sun. Here are some other, sun-free ways to rev up your cognitive skills: