Why Take Vitamin D3? Brain Power!

While D's in school show lack of brain function, D's in pills boost your brain. Vitamin D3 has become the "it" vitamin, thanks to a tsunami of studies showing that D is involved in more activities than a Gossip Girl socialite. From building bone to squelching inflammation, D3 does something good for just about everything that keeps you strong, healthy, and -- according to new research -- smart.

About the smart part: An international team reports that older adults with D deficiencies are at serious risk of losing their memory and thinking skills. The lower their D levels, the greater the decline. That's bad news if you're already a little low, as it will likely drop more as you age: When sun hits your skin at 20, it churns out four times as much D3 as it does when you're 70. (Skin is your body's D3 factory; sun fuels it.) The good news? It's easy to increase your vitamin D3. Learn why combo supplements of calcium-plus-D may not be enough.

Since up to 75% of us are short on D3, taking 1,000 IU a day (1,200 IU if you're over 60) is a no-brainer. Take it with a meal or a little fat (we take ours with our 900 milligrams of DHA omega-3 fatty acids). Find out the best time to take your D3.

We don't yet know if boosting D3 with pills will mean less heart disease, cancer, and diabetes -- and a better memory. But we know for sure that walking outdoors, eating good-for-you foods, getting enough DHA, maintaining a healthy weight -- and probably taking D3 -- will make your brain's RealAge younger. D-lightful.