Abstract
Many patients with diabetes self‐medicate with moderate doses of vitamin E, believing this will improve their health. We therefore examined the effects of oral supplementation with 400 IU/ day of vitamin E (d‐alphatocopherol), on plasma lipoproteins and lipid peroxidation in 12 patients with insulin‐dependent diabetes mellitus, in a randomised, crossover study.
There were no differences in any outcome measures between active treatment and placebo and so this study did not demonstrate any effect of moderate dose vitamin E on plasma lipoprotein levels or peroxidation. However, subgroup analysis showed that whilst in five subjects there was only minor vitamin Eenrichment of plasma lipoproteins on active treatment despite good compliance, in seven subjects there was significant enrichment. In the latter, several measures of lipid peroxidation were lower on active treatment [placebo vs active treatment, median (interquartile range), Wilcoxon's signed rank test]: conjugated dienes 19.2 (15.3–26.4) vs 13.1 (7.49–14.3)umol/I, p<0.05; diene conjugation index 0.83(0.67–0.96) vs 0.53 (0.38–0.6) × 10^−2^, p < 0.05). Thus the effects of moderate dose vitamin E supplements merit further study, particularly as, in large epidemiological studies, their use is associated with a reduced risk of ischaemic heart disease.