Carney E A, Russell R M
J Nutr. 1980 Mar;110(3):552-7. doi: 10.1093/jn/110.3.552.
Dark adaptation, is a reliable and highly reproducible indicator of vitamin A nutritional status in terms of function. Abnormal dark adaptation occurs over a fairly wide range of serum vitamin A values; however, the lower limit of serum vitamin A which is related to normal ocular function has not been determined. We studied dark adaptation in 67 patients with a variety of hepatic and gastrointestinal diseases or with chronic alcoholism. We found that a serum vitamin A level greater than or equal to 40 micrograms % predicted normal dark adaptation 95% of the time, a serum vitamin A level greater than or equal to 30 micrograms predicted normal retinal function 68% of the time and a level greater than or equal to 20 micrograms % predicted normal function 27% of the time. Thus, in individual patients with serum vitamin A levels less than 40 micrograms % one can be sure of vitamin A sufficiency only if a normal dark adaptation response is elicited.
暗适应在功能方面是维生素A营养状况的一个可靠且高度可重复的指标。在相当广泛的血清维生素A值范围内会出现异常暗适应；然而，与正常眼功能相关的血清维生素A下限尚未确定。我们研究了67例患有各种肝脏和胃肠道疾病或慢性酒精中毒的患者的暗适应情况。我们发现，血清维生素A水平大于或等于40微克%时，95%的情况下可预测暗适应正常；血清维生素A水平大于或等于30微克时，68%的情况下可预测视网膜功能正常；血清维生素A水平大于或等于20微克%时，27%的情况下可预测功能正常。因此，对于血清维生素A水平低于40微克%的个体患者，只有当引发正常的暗适应反应时，才能确定维生素A充足。
