Complementary Alternative Cardiovascular Medicine
Complementary Alternative Cardiovascular Medicine
Complementary Alternative Cardiovascular Medicine
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Chapter 5 / Vitamin Therapy and CVD 65<br />
A prospective, double-blind, randomized trial with a combination of<br />
1 mg of folic acid, 400 µg vitamin B 12, and 10 mg of pyridoxine or<br />
placebo administered to 205 patients for 6 mo after successful coronary<br />
angioplasty demonstrated that vitamins significantly reduced Hcy levels<br />
and decreased the rate of restenosis and the need for revascularization of<br />
the target region (40). The extension of this study (41) provided data to<br />
show that Hcy-lowering therapy with folic acid, vitamin B 12, and pyridoxine<br />
was effective in controlling excessive restenosis mechanisms 1<br />
yr after successful coronary angioplasty. The benefit obtained obtained<br />
at 6 mo was maintained at 1 yr, despite cessation of the vitamin therapy<br />
at 6 mo. The authors recommend this combination of vitamins as an<br />
adjunctive therapy for patients who are undergoing coronary angioplasty.<br />
In a study investigating the association of serum Hcy levels, as well<br />
as folate and vitamin B 12 levels, to the rate of in-stent restenosis after 6<br />
mo did not show a relationship (42).<br />
CONCLUSION STATEMENT<br />
Some cohort studies show an inverse relationship between folate status<br />
(dietary folate, serum folate) and serum total homocysteine and risk<br />
for CHD. No RCT have been completed to determine the outcome of<br />
folate supplementation on incidence of MI, stroke or death from CVD.<br />
Grade II The conclusion is supported by fair evidence.<br />
VITAMINS AND ENDOTHELIAL FUNCTION<br />
The vascular endothelium is the primary site of dysfunction in many<br />
diseases, particularly CVD. Research suggests that vitamins E and C and<br />
folic acid have beneficial effects on vascular endothelial function in<br />
patients who are at high risk of CVD, as well as in healthy people (43).<br />
These studies used 300 IU, 600 IU, or 1000 IU of vitamin E or 500 mg,<br />
1 g, or 2 g of vitamin C. The studies showed a decrease in monocyte<br />
adhesion or an improvement in flow-mediated dilation (FMD) of the<br />
brachial artery. A randomized, crossover study of 25 men and 25 postmenopausal<br />
women showed that degradation of endothelial function<br />
after the acute high-fat meal ingestion was mitigated by a concomitant<br />
ingestion of 800 IU of vitamin E (44).<br />
Most studies support a role for vitamins C and E in the improvement<br />
of endothelial function in healthy subjects (45), as well as patients with<br />
diabetes (46) or lipid abnormalities (47). Similar effects of chronic consumption<br />
of vitamins E or C on endothelial function have not been<br />
demonstrated. Therefore, the clinical significance of these acute effects<br />
is not clear.