People who have had a stroke are between two and four times more likely to fracture their hip than healthy people. Researchers think the increased risk might come from stroke patients' higher levels in the blood of homocysteine, an amino acid that can weaken bones. Supplemental folic acid and vitamin B12 have been shown to lower the homocysteine level in potential heart patients. Researchers in Japan wanted to see if these supplements would also decrease hip fractures.

What the researchers wanted to know: Does giving stroke patients folic acid and vitamin B12 decrease their risk of hip fracture?

What they did: The researchers took a group of about 630 people over the age of 65 who had suffered a stroke more than one year prior to enrolling in the study and who still had some paralysis in part of their body. Half of these patients received a daily dose of folic acid and vitamin B12 and the other half received an inactive placebo. As is typical in people recovering from stroke, all of the patients had elevated homocysteine levels at the beginning of the study. The researchers followed these patients for two years and recorded the number of hip fractures in each patient, as well as homocysteine levels and general health.

What they found: All of the patients reported a similar number of falls. But in the half of the group that got supplements there were six hip fractures, and in the placebo half there were 27. At the end of the study period, the patients who took supplements had lower homocysteine than at the start, while homocysteine levels increased on average in the placebo patients. That suggests high levels of homocysteine could account for the more brittle bones. Side effects from the supplements were minimal—12 patients reported nausea and loss of appetite, and their symptoms went away within a week.

What it means to you: Supplemental folic acid and vitamin B12 might be a good idea for stroke patients. Taking folic acid and vitamin B12 carries little risk, and this study suggests that doing so can increase bone strength and prevent a severe and potentially debilitating fracture.

Caveats: The study was done only in Japanese patients, and the findings may not be the same with other populations. In addition, the researchers excluded women with a family history of osteoporosis. So the study did not evaluate the effect of supplements on that group.

Find out more: The same researchers also found a link between lack of vitamin D and risk of hip fracture after stroke. An abstract of that study can be found in the journal Stroke.

For general information about stroke and its effects, try the American Stroke Association.

Read the article: Sato, Y. et al. "Effect of Folate and Mecobalamin on Hip Fractures in Patients With Stroke." Journal of the American Medical Association. March 2, 2005, Vol. 293, No. 9, pp. 1082–1088

Abstract online: http://jama.ama-assn.org