Vitamin D may benefit cancer patients, study says

Vitamin D, if taken for at least three years, could help cancer patients live longer, according to new research from Michigan State University and published in the Journal of Clinical Oncology.

The researchers looked at data related to disease prevention from more than 79,000 patients in multiple studies that randomly compared the use of vitamin D to a placebo over at least a three-year period.  Tarek Haykal, lead author on the study and an internal medicine resident physician at Michigan State University and Hurley Medical Center in Flint, Michigan, and his team focused on information that involved cancer incidence and mortality.

The difference in the mortality rate between the vitamin D and placebo groups was statistically significant enough that it showed how important it might be among the cancer population, Haykal said.

While these findings show promise, Haykal cautioned that the exact amount of the vitamin to take and what levels are needed in the blood are still unknown. He also said that it's unclear how much longer vitamin D extends lifespan and why it has this result.

"There are still many questions and more research is needed," Haykal said. "All we can say is that at least three years of taking the supplement is required to see any effect."

Results show enough promise, however, that Haykal would like to see more doctors, especially oncologists, prescribe vitamin D to patients in general.

"We know it carries benefits with minimal side effects, he said. "There's plenty of potential here."