Kim Mi Kyung, Sasaki Satoshi, Sasazuki Shizuka, Okubo Shunji, Hayashi Masato, Tsugane Shoichiro
Epidemiology and Biostatistics Division, National Cancer Center Research Institute East, Kashiwa, Japan.
Hypertension. 2002 Dec;40(6):797-803. doi: 10.1161/01.hyp.0000038339.67450.60.
In a double-blinded randomized controlled trial, we investigated the long-term effect of vitamin C supplementation on blood pressure. A total of 439 Japanese subjects with atrophic gastritis initially participated in the trial using vitamin C and beta-carotene to prevent gastric cancer. Before and on early termination of beta-carotene supplementation, 134 subjects dropped out of this trial, whereas 120 and 124 subjects took the vitamin C supplement daily at either 50 mg or 500 mg, respectively, for 5 years. Before supplementation, neither systolic nor diastolic blood pressure was significantly related with the serum vitamin C concentration. This relationship was unchanged after adjustment for age, body mass index, and alcohol intake or after stratification by gender. After 5 years, systolic blood pressure significantly increased in groups, regardless of vitamin C dose, compared with baseline. Systolic blood pressure in the high-dose group (500 mg daily) increased from 125.4 to 131.7 mm Hg (5.88 mm Hg increase; 95% confidence interval [CI], 3.11 to 8.65). This value was similar with that of the low-dose group (5.73 mm Hg increase; 95% CI, 2.62 to 8.83) and of the dropout group (4.52 mm Hg increase; 95% CI, 1.26 to 7.77). There was no difference in change of diastolic blood pressure among the 3 groups. In conclusion, we observed no reduction in blood pressure with long-term moderate doses (500 mg/day) of vitamin C supplementation in a high-risk population for stomach cancer and stroke.
在一项双盲随机对照试验中，我们研究了补充维生素C对血压的长期影响。共有439名患有萎缩性胃炎的日本受试者最初参与了使用维生素C和β-胡萝卜素预防胃癌的试验。在β-胡萝卜素补充剂提前终止之前和之时，有134名受试者退出了该试验，而分别有120名和124名受试者每天服用50毫克或500毫克的维生素C补充剂，持续5年。在补充之前，收缩压和舒张压均与血清维生素C浓度无显著相关性。在调整年龄、体重指数和酒精摄入量后或按性别分层后，这种关系没有改变。5年后，与基线相比，无论维生素C剂量如何，各组的收缩压均显著升高。高剂量组（每日500毫克）的收缩压从125.4毫米汞柱升至131.7毫米汞柱（升高5.88毫米汞柱；95%置信区间[CI]，3.11至8.65）。该值与低剂量组（升高5.73毫米汞柱；95%CI，2.62至8.83）和退出组（升高4.52毫米汞柱；95%CI，1.26至7.77）相似。三组之间舒张压的变化没有差异。总之，在胃癌和中风的高危人群中，我们观察到长期中等剂量（500毫克/天）补充维生素C并不能降低血压。
