Recent news stories are all about how jogging can prevent aging. But I wonder how much of that can be attributed to exercise and how much of that can be attributed to being outdoors. From Eurekalert

Researchers at Johns Hopkins are reporting what is believed to be the most conclusive evidence to date that inadequate levels of vitamin D, obtained from milk, fortified cereals and exposure to sunlight, lead to substantially increased risk of death.

In a study set to appear in the Archives of Internal Medicine online Aug. 11, the Johns Hopkins team analyzed a diverse sample of 13,000 initially healthy men and women participating in an ongoing national health survey and compared the risk of death between those with the lowest blood levels of vitamin D to those with higher amounts. An unhealthy deficiency, experts say, is considered blood levels of 17.8 nanograms per milliliter or lower.

Of the 1,800 study participants known to have died by Dec. 31, 2000, nearly 700 died from some form of heart disease, with 400 of these being deficient in vitamin D. This translates overall to an estimated 26 percent increased risk of any death, though the number of deaths from heart disease alone was not large enough to meet scientific criteria to resolve that it was due to low vitamin D levels.

Yet, researchers say it does highlight a trend, with other studies linking shortages of vitamin D to increased rates of breast cancer and depression in the elderly. And earlier published findings by the team, from the same national study, have established a possible tie-in, showing an 80 percent increased risk of peripheral artery disease from vitamin D deficits.

In view of the above, it is ironic that this article views all the sunshine that joggers get as the one negative aspect of jogging.