The other link between vitamin D and osteoporosis has to do with breaking a bone. Most people get vitamin D from exposing their bare skin to sunlight. There is less sun available to make vitamin D during the winter months, so people usually have lower levels of vitamin D in their blood during the winter than the summer. More people break their bones during the winter in both the Northern and Southern hemispheres than other times of the year, and some researchers believe this is because people have lower levels of vitamin D in their bodies during this time. 4
Dr. Volkow’s work has been instrumental in demonstrating that drug addiction is a disease of the human brain. As a research psychiatrist and scientist, Dr. Volkow pioneered the use of brain imaging to investigate the toxic effects and addictive properties of abusable drugs. Her studies have documented changes in the dopamine system affecting, among others, the functions of frontal brain regions involved with motivation, drive, and pleasure in addiction. She has also made important contributions to the neurobiology of obesity, ADHD, and aging. Read more.