TMG No Benefit for Bones in Homocystinuria


The effect of oral betaine on vertebral body bone density in pyridoxine-non-responsive homocystinuria.

Five pyridoxine-non-responsive homocystinuric patients aged 5 to 32 years were treated with oral betaine, 3 g b.i.d, in a double-blind, placebo-controlled, two-year crossover study of its effect on bone mineralization. Betaine therapy significantly reduced mean plasma homocystine (36 +/- 9 (SEM) mumol L-1 to 9 +/- 4 mumol L-1), with variable increases in plasma methionine and no adverse effects. Bone density, measured by computerized tomographic scanning of vertebral bodies, was below normal in all patients at the start of the study, and was not significantly altered by betaine therapy administered according to this protocol.

Gahl WA, Bernardini I, Chen S, Kurtz D…
J. Inherit. Metab. Dis. 1988
PMID: 3148071

Why is this interesting? It’s interesting because several studies show an association between homocysteine and osteoporosis. TMG is known to lower homocysteine. Yet, in this study, there was no increase in bone density despite homocysteine being cut 75%.