If there were an Olympics for antiaging nutrients, vitamin D would have a good shot at the gold medal.
Here's why: Scientists recently examined how blood levels of vitamin D affect aging on a cellular level. High intake was associated with as much as 5 fewer years of chromosome aging!

New Wonder Vitamin
D seems to be particularly relevant to a cellular yardstick of aging called a telomere. These "end caps" on your chromosomes get shorter and shorter with age, but having high blood levels of vitamin D seems to help ensure longer telomeres. That's a good thing, because when telomeres get really short and disappear, cells stop dividing and start to die. Translation: You age and become more vulnerable to disease. Find out more about how to keep your telomeres long -- and your body young.

More D Delights
For years, D -- a vitamin found in food but also synthesized by your skin with a bit of sun exposure -- has been a nutritionist's delight because of its impact on bone health. Now, evidence is growing that the vitamin not only helps build bone and thwart aging but also defends against multiple sclerosis, several cancers (including these), and inflammation in the gums and . . . (whew) . . . lungs. D is definitely moving into bona fide supernutrient territory.

Better Get Yours
Milk remains an excellent source of vitamin D, with 100–125 international units (IU) per cupful. Not into milk? Here are a few other sun-free ways to get your fill of D:

• Choose fortified foods. Food manufacturers are catching on: We want more D! Check the labels of everything -- from orange juice and bread to yogurt and pudding -- to see if they're fortified. Become an expert at reading labels with these tips.
• Eat fish. The richest source of D is salmon (360 IU of vitamin D in 3.5 ounces), but tuna and sardines canned in oil are good sources, too. Check this list of low-mercury fish.
• Have an egg. D is in the yolk, and although 26 IU doesn't sound like much, it all adds up.
• Take a supplement. Just stay below 2000 IU per day from food and supplements combined.

Find out what foods help fight aging with this six-question quiz.