As a vegetarian, one of the things that I have to keep track of is my level of Vitamin B12, because it doesn't occur in the plant world. Naturally vegetarian animals, like the rabbit, find their Vitamin B12 in plants that are infested with insects. But that isn't going to happen in today's spotless kitchens.
When reading about the issues that can crop up for vegetarians with B12 shortages, I came across a relatively new piece of research published in the Journal of Nutrition (Volume 137, Pages 2701-2708) which describes the effect on risk for colon cancer in animals with a shortage of the B family of vitamins. This will be of interest to anyone, and not just vegetarians. Although the research was performed in mice, the gene defects caused by this vitamin shortage could later prove applicable to humans.
Researchers from Tufts University studied the process linked to more than 85 per cent of colon cancers - and found that mild depletion of all four B vitamins (folate, riboflavin, and vitamins B6 and B12) would promote the risk of tumor formation. Previously, studies have suggested that folate deficiency alone promotes the risk of colon cancer. The new research suggests that it isn't just a lack of folate, it is the family of B vitamins that is essential.
Liu and collaborators used cancer-susceptible mice to test if mild folate depletion alone or in combination with the other B-vitamins resulted in changes to the cancer pathway. They tested several biochemical, immunological and genetic markers over a ten-week dietary period, and found that a mild depletion of all four B-vitamins significantly increased the DNA damage localized at an important tumor suppressor gene. Damage to the DNA that codes for this gene would therefore raise the risk of tumor formation.
The problem with this subject of research is that it is stil somewhat controversial. Some earlier studies had reported that folate may in fact increase the risk of the disease. On the other hand, a number of other studies have reported protective benefits from folate. in this most current research, it is folate plus the other family members in the vitamin B group that appear to be so helpful.