本研究係利用重疊病例對照研究法，探討血清維生素A和肝癌發生的關係。對9775 名臺灣地區男性世代追蹤六年後，發現35名肝癌病例。再以年齡、居住地、採血時間配 對方式，選取140名健康對照。所有研究對象於進入研究之初即已採血並貯存血清於-30 ℃。在調整B型肝炎帶原狀態、黃綠色蔬菜攝食頻率、素食習慣之後，血清維生素A對 肝癌有顯著的保護作用，血清維生素A濃度和肝癌危險性之間有顯著的負向劑量效應關 係。進一步只分析血清檢體採集至發病之時間間隔在一年以上的肝癌病例及其對照之血 清維生素A，亦有相同的趨勢。利用多變項條件對數複迴歸分析，調整B型肝炎帶原狀 態、血清維生素A、素食習慣等危險因子後，黃綠色蔬菜每週攝食少於10餐者，其得肝 癌之危險性，為每週攝食10餐以上者的9.95倍(95％C.I.:1.42∼69.92)。蔬菜中除含類胡 蘿蔔素外，也含有其他營養素，又攝食蔬菜較多者，也可能有較健康的生活型態。黃綠 色蔬菜攝食頻率所反映的保養作用，仍有待進一步探討。

　　　　　Nutrients play important roles in human carcinogenesis. To investigate the relationship between serum retinol level and subsequent risk of liver cancer, a nested case-control study was conducted within a cohort of 9775 male adults recruited from 1984 to 1986. a total of 35 liver cases newly diagnosed during the follow-up period were identified, and 140 cancer-free controls matched to liver cancer cases on age, residential area, and time of blood collection were also randomly selected. The blood samples collected in 1984-1986 from all study subjects were stored at -30 ℃ until examinations. Serum retinol levels of cases and controls were determined by high performance liquid chromatography blindly. there was a significant association between serum retinol levle and risk of liver cancer. After adjustment for HBsAg carrier status, darkgreen and yollow vegotable consumption frequency, vegetarian habit; the odds ratio of developing liver cancer for those who had the highest serum retinol level was 0.03 (95% confidence interval=0.002 ∼ 0.42) compared with those who had the lowest level as the referent. There was also a statistically significant dose-response relation between serum retinol level and liver cancer risk. In the further analysis of data for cases who developed liver cancer after 1987 and their matched controls, the association remained unchanged. After adjustment for HBsAg carrier status, serum retinol developing liver cancer for those who consumed darkgreen and yollow vegotable less than ten meals per week was 9.95 (95% confidence interval=1.42 ∼ 69.9) compared with those who consumed more than ten meals a week as the referent.