UCSD researchers say people need to increase their intake of vitamin D to cut their risk of getting colon cancer and several other diseases. The matter of how much vitamin D is enough is controversial.
The Institute of Medicine says most people need no more than 600 "international units" of vitamin D per day to maintain good health.
New research from UCSD suggests daily intake of 4,000 to 8,000 IU is needed for optimum disease prevention.
UCSD researcher Cedric Garland said very few foods are rich in vitamin D.
"Even milk, which is the main source of vitamin D in the U.S. diet, only has 100 international units a glass," Garland said. "So, no one is willing to drink enough milk to get enough vitamin D."
Garland pointed out the average daily intake in the U.S. is only 170 IU. He suggests vitamin D supplements are the way to go.
