Vitamin intake and liver cancer risk: a report from two cohort studies in China.
BACKGROUND
Epidemiologic studies on the relationship between vitamin intake and liver cancer risk are sparse and inconsistent.


METHODS
We evaluated vitamin intake from diet and supplements and risk of liver cancer in 132,837 women and men from China who were recruited into the Shanghai Women's Health Study from 1997 to 2000 or the Shanghai Men's Health Study from 2002 to 2006. In-person interviews, using a validated food-frequency questionnaire, were conducted to collect data on dietary habits. Follow-up consisted of in-person surveys and record linkage. Hazard ratios and 95% confidence intervals were estimated using Cox proportional hazard models with adjustment for potential confounders to compare liver cancer risk among participants with high vs low vitamin intake. All statistical tests were two-sided.


RESULTS
After excluding the first 2 years of follow-up, 267 participants (including 118 women and 149 men) developed liver cancer during an average of 10.9 (Shanghai Women's Health Study) or 5.5 (Shanghai Men's Health Study) years of follow-up. Dietary vitamin E intake was inversely associated with liver cancer risk (P(trend) = .01), as was vitamin E supplement use (hazard ratio = 0.52, 95% confidence interval = 0.30 to 0.90). This association was consistent among participants with and without self-reported liver disease or a family history of liver cancer. Vitamin C and multivitamin use was associated with increased risk among participants with self-reported liver disease or family history of liver cancer, whereas intake of vitamin C and other vitamins from dietary sources was unrelated to liver cancer risk.


CONCLUSIONS
Vitamin E intake, either from diet or supplements, may reduce the risk of liver cancer.
State Key Laboratory of Oncogene and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200032, China.
Wei
W
Zhang
Xiao-Ou
XO
Shu
Honglan
H
Li
Gong
G
Yang
Hui
H
Cai
Bu-Tian
BT
Ji
Jing
J
Gao
Yu-Tang
YT
Gao
Wei
W
Zheng
Yong-Bing
YB
Xiang
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D017610:Calcium Compounds / Q000008:administration & dosage; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D019587:Dietary Supplements / Q000009:adverse effects*; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D014810:Vitamin E / Q000008:administration & dosage*; D014815:Vitamins / Q000008:administration & dosage* / Q000009:adverse effects
D000975:Antioxidants; D017610:Calcium Compounds; D014815:Vitamins; D014810:Vitamin E; D001205:Ascorbic Acid