The value of measuring serum cholesterol-adjusted vitamin E in routine practice

Abstract

BACKGROUND: If the lipid concentration is not taken into account, then in certain situations the vitamin E status of a patient may be wrongly assigned based on serum measurement alone. In this study, the utility of using the calculated vitamin E:cholesterol ratio to determine vitamin E status was compared to the measurement of vitamin E alone. METHODS: The vitamin E:cholesterol ratio was measured in 457 patient samples received for routine vitamin E analysis. Serum vitamin E concentration was determined by high-performance liquid chromatography (HPLC) with UV detection and cholesterol concentration, using a Roche analyser and reagents. RESULTS: The mean vitamin E concentration and vitamin E:cholesterol ratio for the total study population was 22.0 micromol/L and 5.9 micromol/mmol, respectively. Of the 457 patient samples analysed, 57 (12.5%) were found to have a low vitamin E concentration, but only 25 (47%) of these patients had a low vitamin E:cholesterol ratio as well. Two patients both with cholestasis had a normal vitamin E concentration but low vitamin E:cholesterol ratio. CONCLUSION: The determination of vitamin E:cholesterol ratios can be used to better define the vitamin E status of patients with disease states or disorders likely to raise LDL cholesterol, for example cholestasis. For the majority of samples, measurement of serum vitamin E concentration alone is sufficient to establish patient vitamin E status.