Is sunshine more than just a home remedy for a cold? New research suggests it may be: In a study that will be published tomorrow, people with low levels of vitamin D — also known as the "sunshine vitamin" — were more likely to catch cold and flu than folks with adequate amounts. The effect of the vitamin was strongest in people with asthma and other lung diseases who are predisposed to respiratory infections.

People with the worst vitamin D deficiency were 36 percent more likely to suffer respiratory infections than those with sufficient levels, according to the research in this week's Archives of Internal Medicine. Among asthmatics, those who were vitamin D deficient were five times more likely to get sick than their counterparts with healthy levels. And the risk of respiratory infection was twice as high among vitamin D-deficient patients with chronic obstructive pulmonary disease (COPD) than in lung patients with normal levels of the vitamin.

Could the common cold become a thing of the past? Scientists have unraveled the genetic code for all 99 strains of the rhinovirus, but there may be a disconnect between excitement over the feat in the lab versus at pharmaceutical companies that would ordinarily develop a cure or vaccine against infection.

The discovery, published this week in Science, means that, in theory, drug or vaccine developers have a map of possible targets against the cold virus. "There is real promise now, based on full understanding of this virus, that we have never had before," study co-author Stephen Liggett, a professor of medicine at the University of Maryland School of Medicine, told the Baltimore Sun. "Let's get, perhaps, a single pill [that] will kill the virus that day, that moment, and within six hours you are cured. It is possible."

People who get less than seven hours of shut-eye nightly are three times more likely to catch a cold than those who get eight or more hours, according to a new study. Researchers speculate that a lack of sleep may compromise immune function, making people more vulnerable to the common cold. 

"The really striking thing about this study for us is how little differences in sleep can have a big impact on your susceptibility," says Sheldon Cohen, a psychoneuroimmunologist at Carnegie Mellon University in Pittsburgh, Pa., and lead author of the study published today in the Archives of Internal Medicine. 

Previous research has shown that sleep deprivation may trigger changes in the immune system that could make a person more vulnerable to infection. For example, poor sleep may lead to a dip in the number of killer T-cells, which destroy viruses and bacteria, as well as to lower levels of interleukin-2, a protein that stimulates production and growth of many infection-fighting cells, including T-cells. But this is one of the first studies that links sleep deficits to increased susceptibility to the rhinovirus, the most common culprit behind, well, the common cold.