To the Editor: Dr Sato and colleagues1 reported the first evidence that treatment of elderly
patients with hemiplegia following stroke and high levels of plasma homocysteine,
using folate and mecobalamin (vitamin B12), decreases plasma homocysteine
levels and markedly reduces the risk of hip fracture. This treatment did not
affect bone mineral density (BMD) or fall frequency in these patients, consistent
with a recent epidemiological study2 that found
that high homocysteine levels in blood were associated with an increased risk
of nonvertebral fractures in older people independent of BMD or recent falls.
These findings suggest that the reduced fracture risk results from an improvement
of bone quality, possibly countering inhibition of collagen cross-linking
by homocysteine.1,2 However, homocysteine
levels are closely linked to vitamin B12 levels, and serum vitamin
B12 levels in these patients were low at baseline and markedly
increased after the treatment; therefore, vitamin B12 itself might
be directly involved in the improvement of bone quality.
Folate and Vitamin B. JAMA. 2005;294(7):792. doi:10.1001/jama.294.7.792-a