Study: Vitamin B may lower stroke risk
POSTED: Saturday, September 21, 2013 - 2:00pm
UPDATED: Saturday, September 21, 2013 - 2:04pm
CNN — New evidence suggests taking vitamin B supplements may help reduce the risk of stroke.
A study, published this week in the online issue of Neurology, analyzed 14 randomized clinical trials of vitamin B that included a total of 54,913 participants. All of the studies compared the supplement use with a placebo or a very low-dose B vitamin. The patients were then followed for a minimum of six months.
The purpose of this meta-analysis was to see if vitamin B lowered homocysteine levels in the blood, which are associated with atherosclerosis (hardening and narrowing of the arteries), as well as an increased risk of heart attacks, strokes, blood clot formation and possibly Alzheimer's disease.
"Previous studies have conflicting findings regarding the use of vitamin B supplements and stroke or heart attack," said study author Dr. Xu Yuming, with Zhengzhou University in Zhengzhou, China. "Some studies have even suggested that the supplements may increase the risk of these events."
The data showed vitamin B lowered homocysteine levels and, therefore, the risk of stroke overall by 7%. But, researchers noted, taking vitamin B supplements did not appear to affect the severity of those strokes or the risk of death from stroke.
Vitamin B is an important nutrient for the body. It can be found naturally in a variety of foods such as beef liver, certain beans, bananas, light turkey meat, halibut and potato skins.
"B vitamins are essential for living," notes Katherine Tallmadge, a registered dietician and the author of "Diet Simple." "They produce energy in your cells. They are water-soluble vitamins, which means if you take in too much, they are usually excreted by the kidneys. The exception is B12."
The study authors also found that folic acid, a supplemental form of folate (vitamin B9), which is often found in fortified cereals, appeared to reduce the effect of vitamin B. Researchers did not find a reduction in stroke risk for vitamin B12.
"Based on our results, the ability of vitamin B to reduce stroke risk may be influenced by a number of other factors, such as the body's absorption rate, the amount of folic acid or vitamin B12 concentration in the blood, and whether a person has kidney disease or high blood pressure," said Yuming.
Although the scientists admit more research needs to be done, many stroke specialists feel this is a positive step forward.
"I think this is an exciting study, because we need more treatments for stroke," says Dr. Teshamae Monteith, an assistant professor of clinical neurology at the University of Miami School of Medicine and a member of the American Academy of Neurology.
"I believe safe options are necessary," Monteith continued, "and this indeed could be that. But I don’t think people should start ingesting large amounts of vitamin B to avoid strokes. We just aren’t there yet."
Yuming agrees. "Before you begin taking any supplements," he warns, "you should always talk to your doctor."