This re-analysis of the VITATOPS study which found that the homocysteine lowering B vitamins didn’t appear to reduce risk of another stroke, looked at the difference between 6609 patient who were on aspirin, compared to 1463 that were not. Those not on aspirin had a significant reduction in stroke risk, as was predicted from earlier studies showing that homocysteine levels predict stroke risk. Those taking aspirin with the B vitamins had no reduction in risk. This is the second ‘negative’ study which, on re-analysis, supports the theory that aspirin knock out the benefits of B vitamins.
An editorial in the Lancet by stroke expert Dr Gustavo Saposnik says“the available
evidence, suggests that the discordant results from observational
studies and previous randomised trials could be explained by
antiplatelet drugs attenuating or cancelling a small benefit of
homocysteine-lowering therapy with B vitamins in cardiovascular
prevention. The findings from the study also suggest that, in patients
with raised homocysteine, vitamin-B supplementation might potentially
have a role in primary stroke prevention (for non-antiplatelet users).
However, vitamin-B supplementation does not seem to have a significant
benefit in secondary prevention of stroke and cardiovascular disease
when antiplatelet therapy is taken routinely.”
Source - Patrick Holford