Vitamins May Still Reduce Stroke Risk

Stroke risk reduced when vitamins given in higher doses

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Several recent trials have suggested that vitamin therapy does not lower stroke risk. A pair of doctors is disputing those findings, instead pointing out they can be beneficial in higher doses.

A recent study from a scientist at the Robarts Research Institute at Western's Schulich School of Medicine & Dentistry found vitamin B therapy actually increased heart risk in patients with diabetic nephropathy.

"Ask your pharmacist which vitamins are best for you."

In the commentary, Dr. David Spence of The University of Western Ontario and Dr. Meir Stampfer of the Harvard School of Public Health argue that taking vitamins can play a role in lowering stroke risk. They said they now understand how recent findings have come about.

Dr. Spence noted that two issues have been overlooked in interpreting recent clinical trials, including the role of B12 and recognition of the role of renal failure in the results.

He said it is clear that large trials were unable to pinpoint a benefit from vitamins because patients with renal failure were lumped together with those with normal kidney function. Vitamins can be beneficial in patients with healthy kidneys, but could be damaging among those with renal failure.

Dr. Spence said that that when studies included both groups of patients, the results essentially canceled each other out.

He also noted that most of the studies did not use high enough doses of B12 to find a benefit in reducing the risk of stroke in participants.

The commentary was published in the Journal of the American Medical Association.

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Review Date: 
December 20, 2011
Last Updated:
December 23, 2011