Study Sees No Link Between Vitamin D, Diabetes

NEW YORK (Reuters Health) Feb 22 - Low levels of vitamin D don't put older women at greater risk for type 2 diabetes, a large study of U.S. women suggests.海南医学院第一附属医院内分泌科王新军

纽约（路透社）2月22日----一项大型的关于美国妇女的研究表明，维生素D水平低并未导致老年女性发生2型糖尿病的风险升高。

The findings may further temper the enthusiasm for vitamin D that built up in recent years, as studies linked it to lower risks of everything from diabetes, to severe asthma, heart disease, certain cancers and depression.

这一发现可能进一步给近几年狂热的维生素D泼了一盆冷水，一些研究将维生素D和很多疾病如糖尿病、严重哮喘、心脏病、某些癌症和抑郁症的风险降低联系在一起。

"You can't make dietary recommendations based on observational studies," said Dr. Jennifer G. Robinson of the University of Iowa and the lead researcher on the new study.

“你不能靠观察性研究研究制定饮食建议”， 这项新研究的首席研究员Iowa 大学Jennifer G. Robinson博士说。

In an interview with Reuters Health, she pointed to the recent report on vitamin D from the Institute of Medicine (IOM), which said the evidence didn't show that vitamin D has any health benefits beyond building and maintaining strong bones.

在接受路透社记者采访时，她指出，最近医学研究所（IOM）的报告认为，没有证据表明，维生素D有强健骨骼以外其他任何健康益处。

I t also said average Americans already have healthy serum levels of 25(OH)D.

报告还认为，目前美国人的血清平均25（OH）4水平已达健康水平。

The new study, in Diabetes Care published online February 2nd, involved women participating in the Women's Health Initiative, a large government project that looked at the health effects of hormone therapy, diet changes, and vitamin D and calcium supplements on a racially and ethnically diverse population of postmenopausal women.

这项新的研究在线发表在2月2日的Diabetes Care杂志上受试者是参加Women's Health Initiative研究的妇女，Women's Health Initiative研究是一项政府研究项目，旨在观察多种族和多族裔的绝经后妇女人群经激素治疗、饮食改变、维生素D和钙添加剂治疗对健康的影响。

Of 5,140 women who were free of type 2 diabetes at the start of the trial, 6.2% developed the disorder over an average of 7 years.

在开始本研究时的5140例妇女中，平均随访7年之后，6.2％发生了糖尿病。

Dr. Robinson's team found no clear link between the women's blood levels of vitamin D at the outset and their risk of developing type 2 diabetes later on.

Robinson博士的研究小组发现女性基线血液维生素D水平和后来发生2型糖尿病之间没有明显联系。

Initially, there was some evidence of an association. But it disappeared when the researchers accounted for factors like body weight, exercise levels and certain diet habits, like fiber intake -- which are key in the risk of developing type 2 diabetes.

起初，存在一些相关的证据。但是，当研究人员校正了体重、锻炼、饮食习惯，如某些纤维的摄入量等因素之后，其相关性消失。这些因素是2型糖尿病发病的关键危险因素。

"Look at how you get vitamin D," Dr. Robinson said. She noted that the main sources include sun exposure, fatty fish like salmon and mackerel, and vitamin D-fortified dairy products. "People who get those things are a lot different from people who don't."

 “关键看你怎样摄入维生素D”，罗宾逊博士说。她指出，主要来源包括阳光照射、像鲑鱼和鲭鱼等鱼脂肪、维生素D强化的乳制品。“通过这种途径摄取维生素D的人群与不通过这些途径摄入维生素D的人群有许多不同之处”。

And it's those factors, Dr. Robinson said, that may account for the link between vitamin D and lower diabetes risk researchers thought they had found in older studies.

Robinson博士说，就是这些因素，也许可以解释过去一些研究中所发现的维生素D和糖尿病低风险的相关性。

Still, the current study, like past ones, was observational.

尽管如此，目前的研究像过去的研究一样，是一项观察性研究。

A large, government-sponsored randomized trial is currently underway. It will involve 20,000 U.S. adults who are randomly assigned to take vitamin D, omega-3 fatty acids (together or alone) or placebo.

一项大型、政府资助的随机试验目前正在进行中。试验纳入2万例美国成人，随机分配入维生素D、ω- 3脂肪酸（同时或单独服用）或安慰剂组。

The IOM recommends that adults in their 70s and up get 800 IU of vitamin D per day, while everyone else older than 12 months should get 600 IU.

IOM建议， 70岁以上的成人每天应摄入800 IU维生素D，而其他年龄超过12个月的人群每天应摄入600 IU。

Diabetes Care. Posted online February 2, 2011.