B Vitamins May Cut Fracture Risk After Stroke
Folate and vitamin B12 caused five-fold drop in breaks, study finds
WEDNESDAY, March 2, 2005 (HealthDay News) -- Taking folate and vitamin B12 supplements after suffering a stroke can reduce the risk of hip fractures, a new study reports.
The risk of hip fracture is two to four times higher than normal after a stroke. But the study found almost a five-fold reduction in the risk of a hip fracture due to supplement use following a stroke, the researchers said.
"Stroke patients should routinely intake these vitamins to avoid hip fractures, because hip fractures are associated with more deaths, disabilities and medical costs than all other osteoporosis-related fractures combined," said study author Dr. Yoshihiro Sato, a professor at Hirosaki University School of Medicine in Japan.
Sato said these vitamins might reduce fracture risk by lowering homocysteine levels. High levels of homocysteine -- a naturally occurring amino acid -- are a risk factor for both stroke and bone fractures. Sato said homocysteine may interfere with the microarchitecture of the bone.
The finding appears in the March 2 issue of the Journal of the American Medical Association.
Joyce van Meurs, co-author of an accompanying editorial in the journal, said lowering homocysteine levels could have either a direct or indirect effect on bone. Directly, homocysteine may interfere with collagen cross-linking, a process she said is crucial for strong bones. So, lowering levels of homocysteine could lead to stronger bones.
Indirectly, high homocysteine levels are associated with other diseases, such as cardiovascular disease and dementia that may increase the risk of a fall or fracture, according to van Meurs. But, she said, the Japanese researchers accounted for these factors, so they're not likely the reason for the reduced risk seen in this study.
For the study, the researchers followed 559 Japanese stroke patients, aged 65 or over, for two years. All of the study volunteers had had a stroke at least one year before the start of the study, and none was taking any medication that affected bone metabolism.
The study volunteers were randomly split into two groups. Half were given 5 milligrams of folate, a water-soluble B vitamin, and 1,500 micrograms of vitamin B12 daily for two years, while the other half received two placebo pills daily.
At the end of two years, homocysteine levels in the group that received the vitamin combination were reduced by 38 percent.
Six people in the treated group suffered hip fractures during the study period compared to 27 in the placebo group -- a nearly five-fold difference.
"In this Japanese population with a high baseline fracture risk, combined treatment with folate and vitamin B12 is safe and effective in reducing the risk of a hip fracture in elderly stroke patients," Sato said.
Because the vitamins were used in combination, van Meurs said it's not possible to know from this study whether one supplement was more important in reducing the risk of fracture.
"The study shows a clear difference in fracture incidence between patients that receive folate/[B12] treatment and placebo," said van Meurs.
However, she added, "More and larger studies are needed in order to give a conclusive answer whether and to what extent these supplements prevent fractures. If these results hold, this would add an effective, safe and cheap treatment for fracture prevention without adverse side effects. Meanwhile, since these supplements are thought to be beneficial without any adverse effects, I would suggest giving them to patients."
Sato strongly agreed that stroke patients should be given these supplements to help prevent fractures.
The National Library of Medicine offers information on stroke and its complications.