Plasma retinol and a-tocopherol status of the Taiwanese elderly population.

Biochemical assessment of vitamin A and vitamin E status of Taiwanese elderly persons was conducted by quantitative analysis of the concentration of retinol and alpha-tocopherol in plasma samples collected in the Elderly Nutrition and Health Survey in Taiwan (1999-2000). Plasma samples were analyzed by a reverse phase HPLC that can detect retinol and alpha-tocopherol simultaneously. The mean (SE) plasma retinol and alpha-tocopherol values in the 2373 valid samples were 2.73 (0.03) and 27.12 (0.47) microM, respectively, after weighting to the whole population using the SUDDAN program. Among the elderly persons studied, 99.52% of the population demonstrated normal plasma vitamin A status (plasma retinol equal to or greater than 0.7 microM or 0.2 microg/mL). The prevalence of deficient (less than 11.63 microM or 5 microg/mL) and marginal (greater than or equal to 11.63, but less than 16.28 microM or 7 g/mL) plasma alpha-tocopherol concentrations in the elderly population in Taiwan were 2.91% and 10.61%, respectively. However, the prevalence of low or inadequate vitamin E status decreased to 4.20% when the plasma alpha-tocopherol/cholesterol ratio was used as the indicator (less than 2.8 microg/mg). Results of the multiple linear regression analysis revealed that serum lipids had a strong influence on plasma alpha-tocopherol concentration. The results also showed that elderly men, those living in two Central Taiwan regions, and subjects with plasma cholesterol levels higher than 200 or lower than 174 mg/dL all had higher risk of low or inadequate alpha-tocopherol status than their counterparts. In conclusion, the plasma vitamin A and vitamin E status in the Taiwanese elderly are comparable to those reported for adults of developed Western societies.