Study: Calcium, vitamin D pills do not prevent colon growths that can lead to cancer

Associated Press

A major study finds that taking calcium or vitamin D pills does not help prevent growths that can lead to colon cancer in people who have had at least one in the past.

It’s the latest setback among many for efforts to prevent disease through vitamin supplements. The calcium finding was especially disappointing – three previous studies suggested calcium would help, but the new one, a more-rigorous test, found no benefit.

“That was a big surprise. We thought we understood calcium because the data was really quite, quite strong,” said Dr. John Baron of the University of North Carolina at Chapel Hill.

He led the new study, published in today’s New England Journal of Medicine. The National Cancer Institute sponsored it and Pfizer Consumer Healthcare provided the pills.

It involved 2,259 people recently diagnosed with polyps, precancerous growths removed during colonoscopy. They were assigned to take either 1,000 international units of vitamin D3, 1,200 milligrams of calcium, both or neither. Women could choose to get calcium and then be given either real or dummy pills of vitamin D.

“We did that so that women concerned about bone health would feel comfortable taking part,” because they were ensured of getting calcium if they wanted it, Baron explained.

Followed up three to five years later, 43 to 45 percent of all study participants had developed a new polyp, regardless of whether they took calcium, vitamin D, both or neither. Even when researchers took age, gender and other factors into account, supplement use made no difference in the results.