One of the surprises of the study was that vitamin B-6 deficiency was still linked to heart disease and stroke in study participants independent of levels of homocysteine. Previous research has suggested that high levels of this amino acid may be linked to heart disease and stroke risk as a result of too little vitamin B-6 or folic acid intake.
In the study vitamin B-6 levels were lower in men and women who had heart disease and stroke than in healthy people. A B-6 deficiency was found in about 20 percent of the individuals, says the study's lead author, Killian Robinson, M.D., staff cardiologist and associate professor of medicine of the Cleveland Clinic.
"The 20th percentile is one-fifth of the population. That means one-fifth of the population has vitamin B-6 levels that may put them at risk for cardiovascular disease," he says.
Those in the study with a B-6 deficiency were almost twice as likely to have heart disease and stroke than those without a deficiency. "Having a vitamin B-6 deficiency proved to be a very powerful risk factor for heart disease and stroke," says Robinson.
In an editorial commenting on the new research, Gilbert Omenn, M.D., Ph.D., of the University of Michigan, Ann Arbor, cautions that the results of the new study should be considered preliminary. While the study indicates that vitamin B-6 may have a protective role against heart disease and stroke, a more detailed analysis of the B vitamins' independent effects on cardiovascular disease is needed. The statistical associations don't necessarily constitute "effects," says Omenn, executive vice president for Medical Affairs at UM and CEO of the
Contact: Carol Bullock
American Heart Association