Vitamin D May Benefit Colon Health

There has been a seemingly endless supply of new research demonstrating benefits related to having enough vitamin D in the body. There is so much new research on vitamin D that we could literally write several articles about it every month. However, that would might get tiresome, so we try to only write about what we consider to be the most interesting studies.

Vitamin D has been linked to a surprising number of health benefits, including heart and bone health, cognitive function, cancer risk, diabetes risk and even risk of death. So it doesn't come as a huge surprise that a new study, published in the British Medical Journal, reported that vitamin D may reduce colorectal cancer risk. What makes it notable is the finding that it may reduce that risk by 40%. Even more striking is the size of the study, involving over half a million participants, making it, by far, the largest study of its kind.

The researchers used data from the European Prospective Investigation into Cancer Study (EPIC), "a cohort of more than 520,000 participants from 10 western European countries." From that pool, researchers found 1248 participants who developed colorectal cancer after they were enrolled in the study. For the analysis, circulating vitamin D concentrations were measured and questionnaires were used to obtain dietary and lifestyle information on each of the participants. Upon analyzing the data, the researchers determined that vitamin D "concentration showed a strong inverse linear dose-response association with risk of colorectal cancer." When comparing pre-defined quintile ranges, "patients in the highest quintile had a 40% lower risk of colorectal cancer than did those in the lowest quintile." The lowest quintile had blood vitamin D concentrations in the ranges less than 25 nanomoles per liter, while the highest ranges were greater than 100 nanomoles per liter.

In summary of their findings, the researchers stated that "the results of this large observational study indicate a strong inverse association between levels of pre-diagnostic [vitamin D] concentration and risk of colorectal cancer in western European populations."

Vitamin D comes in several forms. The two forms of vitamin D that come from diet and supplements, cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2), are converted within the body into 25-hydroxyvitamin D, the "storage form" of vitamin D, and 1,25-hydroxyvitamin D, the "active form."

Cholecalciferol (vitamin D3) is the more bioavailable form of the two dietary forms. This is the same form produced in the skin when exposed to ultraviolet light. Whole Health only sells the vitamin D3 form. Learn more about Vitamin D3 and its potential benefits here.

1. Jenab, M., H. B. Bueno-de-Mesquita, et al. "Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations:a nested case-control study." Bmj 340: b5500.