Colorectal cancer is the third most common type of cancer in men and women in the United States according to data from the American Cancer Society.
A recent study published in the British Medical Journal looked at the association between people's vitamin D blood levels, their dietary intake of vitamin D and calcium, and their risk of colorectal cancer in European populations. 520,000 people from 10 Western European countries participated in this study. This is an enormous number! The people who were in the study gave blood samples and completed dietary and lifestyle questionnaires between the years 1992 and 1998.
The findings confirm what other studies, which I talk about in my book have shown us. Lower levels of vitamin D in the blood were associated with a higher risk for colorectal cancer. Higher concentrations of vitamin D in the blood were associated with a lower risk for this cancer. Specifically, people who had the highest blood levels of vitamin D in this study, had a 40% lower risk of colorectal cancer than those in the lowest levels of vitamin D in the blood.
In my opinion, this is just one more reason, further confirmed why everybody should take a basic dose of vitamin D, and should try to optimize their levels of vitamin D if they are able to get blood tests.
For people who do not have a blood test, and who are otherwise healthy adults I recommend 2000 IU of vitamin D daily.