The American Cancer Society currently recommends that people should be taking 1,000 international units of vitamin D every day -- or one vitamin D supplement pill daily. However, without more research on the specific impact that vitamin D has on cancer prevention and cancer outcomes, many experts said they are unable to provide a one-size-fits-all recommendation to cancer patients on how they can use this vitamin to improve their chances of survival.
"We need to get arms around vitamin D and its impact on health," Lichtenfeld said. "We need to figure out how much should we be taking, how and if it reduces cancer risk or changes the course of cancer once it is diagnosed.
"These are very important questions, and we need to get the appropriate people together to make recommendations on what we should be telling our patients about this," he said.