商业托福阅读：VitaminDLowersRiskofDeath

会计考友

　　【Introduction】
　　Doctors have long known that vitamin D is essential to good health. Get enough of it and it ensures strong bones and teeth. But a new study this week suggests an even more extraordinary benefit: a lower risk of death.
　　【Section One】Article
　　Vitamin D Lowers Risk of Death
　　The new paper, published in the Sept. 10 issue of the Archives of Internal Medicine, is a meta-analysis of 18 previously published studies on the vitamin. None of the original experiments was specifically designed to study how vitamin D affects mortality — the trials involved conditions such as bone fractures, bone mineral density, congestive heart failure and colorectal cancer — but all of them tracked participants' death data. Overall, researchers found, people who took daily vitamin D supplements were 7% less likely to die during the study — from any cause — than people who didn't.
& t8 l- a0 a* z( j3 ^　　The study's authors still don't know exactly how the vitamin may reduce people's death risk, but their findings are in line with a spate of recent research linking the vitamin to a wide range of health benefits. Not only does it promote calcium absorption and bone maintenance, but vitamin D also appears to stimulate the immune system, inhibit cellular proliferation and spur cell differentiation — in turn, those processes could reduce the aggressiveness of cancer tumors or keep artery-clogging plaques from growing. Indeed, studies have suggested that low levels of vitamin D may be associated with a higher risk of death from certain cancers, heart disease and diabetes.
. \/ U* o  z* \: S/ M　　The current analysis looked at data on 57,311 participants, most of whom were middle-aged or elderly and in generally good health. Those in intervention groups took daily doses of vitamin D — ranging mostly from 400 IU to 833 IU per day, with a study size–adjusted mean intake of 528 IU a day. Compared with people who weren't given supplements, the test groups had up to a five times greater blood level of vitamin D and a significantly reduced risk of death. Though there's no medically recommended optimum level of the vitamin, "throughout human evolution when the vitamin D system was developing, the 'natural' level... was probably around 50 ng/mL or higher," writes Dr. Edward Giovannucci, a professor of nutrition and epidemiology at the Harvard School of Public Health, in an accompanying editorial. "In modern societies, few people attain such high levels, and levels below 10 ng/mL or 15 ng/mL are not uncommon."
* x/ q( n# l' r$ N0 Y" ^　　If people can't get enough natural vitamin D from food or sun exposure, which synthesizes it in the skin, then daily supplements may be a good alternative — and the current study shows that an intake of up to 800 IU a day is safe. In the 18 studies that researchers analyzed for the current report, none of the participants taking supplements — even at a 2,000 IU daily dose — surpassed the 50 ng/mL mark. According to Giovannucci, people should reasonably shoot for levels of 30 ng/mL to 40 ng/mL, and doctors should consider testing patients who are at risk for deficiencies in vitamin D.
　　【Section Two】Vocabulary
( L+ z% o) ?3 h) E; L' v0 H　　1. mortalityn. 死亡率
　　2. fracturen. 破裂, 骨折；v. (使)破碎, (使)破裂
　　3. congestiveadj. 充血的
　　4. diabetesn. [医] 糖尿病, 多尿症
　　5. evolutionn. 进展, 发展, 演变, 进化
6 R9 U; Q5 z" G& ]4 C- q' ~　　6. bone fractures 骨折
) g$ v6 W/ p3 H! f3 ~　　7. bone mineral density 骨密度
# b2 L9 z0 T* C. }/ U　　8. immune system 免疫系统
　　9. cell differentiation 细胞分化
$ U" {& b9 m+ y/ L/ W2 N　　【Section Three】Homework
　　1. Please translate the blue sentence into Chinese.
　　"Not only does it promote calcium absorption and bone maintenance, but vitamin D also appears to stimulate the immune system, inhibit cellular proliferation and spur cell differentiation."
, L* ?) L0 O- z0 t" W- u3 J* o　　2. What is the main idear of this Article?
　　3. A intake of how many vitamin D a day is safe from the current study?
　　4. The article mentioned "Researchers found, people who took daily vitamin D supplements were 7% more likely to die during the study — from any cause — than people who didn't." Right?

会计考友

　　参考答案:
　　1. 维生素D不仅能促进钙的吸收、骨骼的保养，还能激活免疫系统、抑制细胞扩散、刺激细胞分化。
. Y( l/ I& }& z7 e5 v$ b3 k6 _　　2. No standard answer.
$ N) o2 P% q0 q7 ~- G& c　　3. The current study shows that an intake of up to 800 IU a day is safe.
2 g* F- J' n) m" u3 o' m: I! w　　4. False！You can find the correct answer in the first paragraph. Not "more", but "less".
　　Text: "Overall, researchers found, people who took daily vitamin D supplements were 7% less likely to die during the study — from any cause — than people who didn't."