Johnson E J, Krall E A, Dawson-Hughes B, Dallal G E, Russell R M
USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.
J Am Coll Nutr. 1992 Dec;11(6):682-6. doi: 10.1080/07315724.1992.10718267.
Two hundred eighty-four female adults (aged 40-70 years) were longitudinally studied to investigate the relationship between dietary supplemental vitamin A and serum biochemical markers of vitamin A toxicity. Serum retinol, retinyl esters, and retinol-binding protein (RBP), alkaline phosphatase and aspartate aminotransferase activities and bile acids were measured at baseline, 1 and 2 years. Fasting serum retinol and retinyl ester concentrations were determined by high-performance liquid chromatography, and dietary and supplemental intake of vitamin A were assessed by 3-day food records. There was no difference in dietary vitamin A intake between supplement users and nonusers. In supplemental users, the mean +/- SEM supplemental vitamin A intake was 952 +/- 81 IU/day (range 250-5000 retinol equivalents/day). Serum retinol, retinyl esters, and RBP concentrations were not different between the two groups during the 2-year period. For each group, serum retinyl esters significantly increased over time (p < 0.03), but the magnitude of the increase was not different between the groups. Serum levels of retinol, retinyl esters, and RBP were not correlated with vitamin A intake or age in either group. Biochemical measures of liver damage (serum alkaline phosphatase and aspartate aminotransferase activities and serum bile acids) were not related to serum retinol, retinyl esters or RBP concentrations, nor were they different between nonusers and users of supplemental vitamin A. This study provides evidence that long-term supplemental vitamin A in doses commonly found in multivitamin supplements does not present a risk for hypervitaminosis A.
对284名成年女性（年龄在40 - 70岁之间）进行了纵向研究，以调查膳食补充维生素A与维生素A毒性血清生化标志物之间的关系。在基线、1年和2年时测量血清视黄醇、视黄酯、视黄醇结合蛋白（RBP）、碱性磷酸酶和天冬氨酸转氨酶活性以及胆汁酸。通过高效液相色谱法测定空腹血清视黄醇和视黄酯浓度，并通过3天食物记录评估维生素A的膳食和补充摄入量。补充剂使用者和非使用者之间的膳食维生素A摄入量没有差异。在补充剂使用者中，平均±标准误补充维生素A摄入量为952±81 IU/天（范围为250 - 5000视黄醇当量/天）。在两年期间，两组之间的血清视黄醇、视黄酯和RBP浓度没有差异。对于每组，血清视黄酯随时间显著增加（p < 0.03），但增加幅度在两组之间没有差异。两组中血清视黄醇、视黄酯和RBP水平均与维生素A摄入量或年龄无关。肝脏损伤的生化指标（血清碱性磷酸酶和天冬氨酸转氨酶活性以及血清胆汁酸）与血清视黄醇、视黄酯或RBP浓度无关，补充维生素A的非使用者和使用者之间也没有差异。这项研究提供了证据，表明在多种维生素补充剂中常见剂量的长期补充维生素A不会带来维生素A过多症的风险。
