Vitamin D may cut risk of colorectal cancer

NEW YORK, Feb 10 (Reuters) Taking 1,000 to 2,000 international units (IU) of vitamin D each day may safely reduce the risk of colorectal cancer, according to pooled data from published studies.

The current findings contradict some prior individual studies that found that vitamin D intake did not seem to protect against colorectal cancer. However, it is possible that the dose may simply have been too low to provide a benefit, researchers say.

The present analysis, reported in the American Journal of Preventive Medicine, included data from five studies that looked at the association between blood levels of 25-hydroxy-vitamin D, which provides a good estimate of vitamin D levels in the body, and colorectal cancer risk.

Dr Edward D Gorham, from the Naval Health Research Center in San Diego, California, and colleagues found that as blood levels of vitamin D rose, the risk of colorectal cancer fell. Risk was reduced by 54 per cent in groups with the highest vitamin D levels relative to those with the lowest levels.

In the final analysis, a blood level of 33 nanograms per milliliter (ng/mL) or higher was associated with a 50 per cent decreased risk of colorectal cancer relative to a level of 12 ng/mL or lower.

The researchers believe that the target blood levels could be achieved with intake of 1,000 to 2,000 IU of vitamin D per day.

Moreover, they note that the National Academy of Sciences has established that a dose of 2,000 IU/day is safe.

Reuters MS DB0928