There is no need for most people to take vitamin supplements and some may even be linked to a higher risk of dying in older women, according to a study published Monday in the United States.
Iron stood out among supplements as a particular concern, while calcium appeared to be linked to lower death risk, said the study in the Archives of Internal Medicine, a journal of the American Medical Association.
With about half of Americans taking vitamin pills of some kind, the study aimed to examine whether the $20 billionsupplement industry was having any effect on extending lifespan in an already well-nourished population.
The US and Finnish researchers examined data from the Iowa Women's Health Study, including surveys filled out by 38,772 women with an average age of 62.
Women self-reported their supplement use in 1986, 1997 and 2004, and data showed their use rose from 66 percent of survey-takers at the start to 85 percent by 2004.
Those who took supplements showed a range of healthy lifestyle factors, and were more likely than non-supplement users to be non-smokers, eat low-fat diets and exercise.
But in many cases they showed a higher risk of dying than their supplement-free counterparts.
"We think the paradigm 'the more the better' is wrong," wrote doctors Goran Bjelakovic of the University of Nis in Serbia and Christian Gluud of Copenhagen University Hospital in Denmark in an accompanying commentary.
These findings "add to the growing evidence demonstrating that certain antioxidant supplements, such as vitamin E, vitamin A, and beta-carotene, can be harmful," they said.
"We cannot recommend the use of vitamin and mineral supplements as a preventive measure, at least not in a well-nourished population."


据法新社10月11日报道，根据美国本周一公布的一项研究表明，对大部分人来说，服用维生素药物都是没有必要的，一些维生素类药剂甚至可能导致中老年妇女死亡率升高。

美国医学协会期刊《内科医学档案》的一份研究报告指出，众多维生素类药物中，铁应被特别关注，而钙则似乎可以降低死亡风险。

大约有一半的美国人服用各种维生素药物，这次研究的目的就是为了检验每年产值高达200亿美元的保健药品产业是否真的能帮助已经营养良好的人群延年益寿。

美国和芬兰的研究人员仔细分析了爱荷华州妇女健康研究的数据，该研究调查了总共38772名平均年龄为62岁的妇女。

这些妇女在1986年、1997年和2004年报告了她们服用维生素药物的情况，数据显示她们服用维生素药物的比例从1986年的66%上升至2004年的85%。
那些服用维生素药物的女性显示出了更为健康的生活方式，比起不服药物的女性，她们中不吸烟的人更少，她们摄入更少的脂肪且锻炼更多。

但在许多情况下，比起不服药物的那部分女性，她们要却承担更高的死亡风险。


"我们认为人们固有的观念'多多益善'是错误的，"塞尔维亚尼什大学的格兰•别拉科维奇博士和丹麦哥本哈根大学医院的克里斯蒂安•格鲁德博士在一篇合作文章中这样说到。

他们还指出，这些发现"进一步证明了某些抗氧化剂，比如维生素E、维生素A和β-胡萝卜素可能是对人体有害的。"

"我们不建议将服用维生素和矿物质补充剂作为预防疾病的手段，至少对于营养良好的人来说没必要这么做。"

• journal [´dʒə:nəl] n.日记；日报；杂志 (初中英语单词)
• medical [´medikəl] a.医学的；医疗的 (初中英语单词)
• healthy [´helθi] a.健康的 (初中英语单词)
• recommend [,rekə´mend] vt.推荐；使受欢迎 (初中英语单词)
• mineral [´minərəl] n.矿物 a.矿物的 (初中英语单词)
• measure [´meʒə] n.量度；范围 vt.测量 (初中英语单词)
• internal [in´tə:nl] a.内部的；国内的 (高中英语单词)
• billion [´biljən] num.万亿 (高中英语单词)
• denmark [´denmɑ:k] n.丹麦 (高中英语单词)
• calcium [´kælsiəm] n.钙 (英语四级单词)
• supplement [´sʌplimənt, ´sʌpliment] n.增补；增刊；附录 (英语四级单词)
• taking [´teikiŋ] a.迷人的 n.捕获物 (英语六级单词)