A large study of women at risk for heart disease found no differences in cancer rates among those who took a daily B-vitamin supplement for 7 and a half years and those who took a placebo.
In the past, studies have shown that people with LOW levels of vitamin B often have a GREATER risk for certain cancers.
But a new research suggests that simply INCREASING vitamin B levels with a daily supplement does not lower the risk for cancer.
Doctors from Brigham and Women's Hospital studied more than 5,400 women at high risk for heart disease who were taking either taking a daily supplement of vitamins B12, B6, and folic acid -- or a PLACEBO.
The women took the pills for more than 7 years but did not lower their overall risk for heart disease OR for cancer.
"This study shows that supplementation with the combined B vitamins provided no beneficial effect and no harmful effect. So in terms of cancer risk, this may not be an effective approach," Dr. Shumin Zhang of Brigham and Women's Hospital and Harvard Medical School in Boston, who led the study, said in a telephone interview.
However, researchers did find some POSSIBLE benefit for older women-in those over 65, there were 25% FEWER cancers among women taking supplements. Experts say the findings will require confirmation.
In the meantime, women should focus on PROVEN methods to reduce cancer risk - such as eating lots of fruits and vegetables, getting regular exercise, and refraining from smoking or drinking more than 1 alcoholic beverage per day.
It is important that people get the proper amount of the various B vitamins, which are essential nutrients for growth, development and numerous other functions. For example, folic acid is important in the production of red blood cells and is important for women to prevent certain birth defects of a baby's brain and spine, known as neural tube defects.