We live in a culture that’s obsessed with who or what’s “the best.” What’s the best exercise? The best food? The best athlete, the best actor, the best deal, the best song, best album, best actress, best candidate, best television, best laptop, gaming system, comedian and on and on and on. So it comes as no surprise to find that researchers have endeavored to discover the best vitamin for the body. Vitamin C? Think again.

According to researchers, it’s the vitamin you get simply by walking outside on a sunny day: vitamin D. Now I know what you’re thinking: How does one define “best”? My interpretation of the best vitamin— like the best song, or TV drama—is different from someone else’s interpretation. So the researchers defined what’s “best” as the vitamin that will prolong your life the most.

After reviewing data from 18 trials of tests that involved 57,000 people, researchers from the International Agency for Research on Cancer in Lyon, France, concluded that taking vitamin D supplements will prolong life by warding off diseases. The study is published in the September issues of Archives of Internal Medicine and Forbes.com .

Six years after the initial studies were done on the 57,000 people, the researchers followed up on the subjects to see what, if any, effect vitamin D had on their bodies. What they found was those who took vitamin D supplements had a 7 percent chance of living longer than the people who did not take vitamin D supplements (approximately 4,800 of the 57,000 people died in between those six years)! Now, granted, 7 percent isn’t a huge number, but it’s large enough to encourage researchers that their findings could be a breakthrough in how medicines are made to treat diseases like cancer.

While the subjects in the studies took varying doses of vitamin D (from as much as 2,000 IUs to as little as 300 IUs), lead researcher Dr. Phillipe Autier recommends no more than 600 IUs as a daily supplement. As you may know, vitamin D is a fat-soluble vitamin and can be hazardous to your health if taken in too high of dosages. In fact, too much vitamin D may cause cancer, according to a study published in a 2004 issue of the International Journal of Cancer.

So, to paraphrase infomercial magnate Ron Popeil, how much vitamin D do you need and where can you find it? As aforementioned, moderate amounts of sunlight each day causes the body to makes its own vitamin D, but actual healthy food sources include milk, dandelion greens, oatmeal, sweet potatoes and oily fish like salmon, swordfish, mackerel and sardines (3 ½ oz salmon=350 IUs). The herbs alfalfa, horsetail, nettle and parsley also contain Vitamin D.

However you get it, as always, make sure it’s from an organic source as there are more vitamins in them than non-organic food sources. Just as in sports, in life, the best offense is a good 'D'-fense.