A new trial has some unfortunate news: treating one extremely unpleasant disease with vitamin D or calcium isn’t working.

Neither of them, either separate or combined, appear to do a good job at preventing colorectal polyps based on a new placebo-controlled trial that follow patients for about 5 years, according to a MedPage Today report.

It’s a surprise to scientists, who had relied on years of previous studies that seemed to indicate Vitamin D and Calcium were quite effective at protecting against precancerous polyps.

John Baron of the University of North Carolina Chapel Hill and fellow researchers published their findings in the New England Journal of Medicine. The findings are sure to shake up the medical community as it contradicts smaller randomized trials, including one Baron himself conducted back in 1999, which seemed to indicate that calcium supplementation was a good tool in the fight against colorectal polyps.

It’s an important study because it’s one of the first to look at Vitamin D, and the largest to look at calcium on this particular issue. The calcium data in particular was surprising, and scientists are going back to the drawing board to figure out why they got these results.

The study examined 2,259 people, who were at least 45 but no older than 75, and had at least one colorectal adenoma removed within the last four months. Some were randomly assigned 1,000 IU of vitamin D3 and 1,200 mg of calcium, while the others received a placebo.

Then, there was a follow-up colonoscopy between 3 and 5 years later.

After the study, Baron said according to the report that the team can say with confidence that a 1,000 IU dose of Vitamin D isn’t effective. The case of Calcium is a bit more complicated, especially in light of previous studies, but the results were certainly not good.