Current Issues
There are many researches done on many different types of vitamin. In fact, there are different types of organizations that are dedicated to researching out that specific vitamin. To find out about all the researches that are going on would probably take months or even years! And there are only so much I can put on this page.
UV Radiation and vitamin A deficiency
What you may have heard is that spending way too much time in the sun could give you skin cancer. What that alludes to is the fact that UV radiation from the sun giving you the skin cancer. What scientists have found so far is the fact that UV radiation induces vitamin A deficiency within the skin. What is still unkown about this research is the detailed damage UV radiation does to the skin. However, what they did find out is how UV irradiation blocks the ability of skin cells to detect and respond to retinoic acid. This inability to recognize retinoic acid triggers certain boichemical changes that upsets the balance between healthy and dying skin cells.
To learn more, see the article @http://www.sciencedaily.com/releases\1999\03\990331063314.htm
Studies on storage of vitamin A
This research studies how well the body stores vitamin A. What these scientists found out is that the carotenoids that promote vitamin A production are not very sufficient in storing and converting vitamin A. This research is supported by the World Health Organization, which still supports many of these vitamin researches.
To see this article, go to http://www.sciencedaily.com/releases\1998\08\980814064805.htm