Previous observational studies demonstrated an association
between homocysteine levels (Hcy) and cardiovascular diseases. More
specifically, high Hcy levels can be classified as a risk factor for
cardiovascular disease. Several B vitamins, such as folate, have been shown to
lower Hcy levels. Studies have determined that plasma Hcy levels can be reduced
by approximately 25% with the use of daily 0.5 – 5.0 mg folic acid supplements.
The aim of this research paper was to investigate
whether supplement use reduces the risk developing a cardiovascular disease.
All participants in the study currently had a history of vascular disease
and/or diabetes. Patients were randomly assigned to take either a placebo pill
or a pill containing folic acid (2.5 mg) and vitamins B6 (50 mg) and
B12 (1 mg) for 5 years.
Results showed an increase in the concentration of
folate, vitamin B6 and B12 in the active-treatment group
and no significant changes in the placebo group. Furthermore, the daily
supplements administered significantly lowered Hcy levels. However, there was
no significant reduction in death due to cardiovascular causes (i.e. myocardial
infarction and stroke). Therefore, taking vitamin B supplements is an ineffective
preventative treatment for cardiovascular disease. It is important to note that
no serious adverse effects were caused by the treatment.
Since subjects in this study were from various countries
around the world, some had access to folate-fortified foods, whereas others did
not. The authors noted that this exposure most likely reduced the number of
individuals with significantly increased Hcy levels. As a result, vitamin B
supplementation may not have been as effective as it could have been.
This study was funded and supported by the Canadian
Institutes of Health Research Grant and by Jameison Laboratories. Nevertheless,
the authors of this paper noted that this did not create any relevant potential
conflicts of interest.