研究發現：維生素片大多沒啥用 吃錯還會致病

Vitamin and mineral supplements are a staple in many people's diets, but there is increasing evidence to suggest the most popular ones are essentially useless.

維生素和礦物質補充劑是許多人日常膳食中的固定組成部分，但越來越多的證據表明，最受歡迎的一些維生素補充劑其實都沒什麼用。

A new systematic review of data and trials published between January 2012 and October 2017 found that many popular multivitamins – as well as vitamin C, vitamin D, and calcium supplements – had no real advantage to people's health and that there was no evidence taking them reduced the risk of cardiovascular disease, heart attack, stroke, or early death.

一項對2012年1月至2017年10月間發佈的數據和試驗的系統回顧發現，維生素C、維生素D、鈣質補充劑和許多受歡迎的複合維生素對人們的健康沒有實質性的好處，而且沒有證據表明服用這些維生素能夠降低心血管疾病、心臟病發作、中風或早逝的風險。

The study, published in the Journal of the American College of Cardiology, was led by researchers at St. Michael's Hospital and the University of Toronto.

這項發表在《美國心臟病學會期刊》上的研究是由聖米高醫院和多倫多大學的研究人員帶頭開展的。

"We were surprised to find so few positive effects of the most common supplements that people consume," said Dr. David Jenkins, the lead author of the study.

研究報告的主要作者戴維·詹金斯博士稱：“我們驚訝地發現，人們最常服用的補充劑居然收效甚微。”

"Our review found that if you want to use multivitamins, vitamin D, calcium or vitamin C, it does no harm – but there is no apparent advantage either."

“我們的回顧發現，如果你想服用複合維生素、維生素D、鈣片或維生素C，對你的身體是無害的，但也沒有明顯的益處。”

There were, however, a few apparently advantageous supplements. Folic acid and B vitamins with folic acid may reduce the risk of cardiovascular disease and stroke, the study found.

不過，研究也發現了幾種對人體明顯有益的補充劑。葉酸和含有葉酸的複合維生素B或許能降低患心血管疾病和中風的風險。

Niacin (a form of vitamin B3) and antioxidants, meanwhile, were associated with a higher risk of death by any cause, albeit a very small increase.

此外，煙酸（維生素B3）和抗氧化劑會導致死亡風險升高，不過只是略微升高。

The researchers say these higher risks could be related to niacin's adverse effects on blood-sugar levels, or that when taken in high doses, antioxidants can be harmful.

研究人員稱，這可能和煙酸對血糖水平的負面影響有關。研究指出，大量服用抗氧化劑會對人體有害。

Alternatively, it could have something to do with people sometimes thinking that taking vitamins can be a substitute for a healthy, balanced diet.

另一方面，服用維生素無益也和人們的觀念誤區有關，有些人認爲服用維生素可以替代健康平衡的膳食。

"These findings suggest that people should be conscious of the supplements they're taking and ensure they're applicable to the specific vitamin or mineral deficiencies they have been advised of by their healthcare provider," Jenkins said.

詹金斯說：“研究結果表明，人們應該瞭解自己服用的補充劑，聽從醫囑，確保這些補充劑能補充自身所缺乏的某種維生素或礦物質。”

The vitamins the team reviewed were A, B1, B2, B3 (niacin), B6, B9 (folic acid), C, D, and E, as well as carotene, calcium, iron, zinc, magnesium, and selenium.

研究團隊的研究對象包括維生素A、維生素B1、維生素B2、維生素B3（煙酸）、維生素B6、維生素B9（葉酸）、維生素C、維生素D和維生素E，還有胡蘿蔔素、鈣、鐵、鋅、鎂和硒。

Research has found that some vitamins are more useful than others. For example, zinc has been linked to shortening the effects of a cold – something vitamin C doesn't do, despite what people think.

研究發現，一些維生素比其他維生素更有用。比如，鋅能縮短感冒週期，而維生素C卻不能，儘管人們一直以爲維生素C能讓感冒好得快。

Vitamin D can also be difficult to get from food, so if you're deficient, supplements may also be effective.

維生素D難以從食物中獲得，所以如果你缺乏維生素D，那麼服用補充劑會比較有效。

"In the absence of significant positive data – apart from folic acid's potential reduction in the risk of stroke and heart disease – it's most beneficial to rely on a healthy diet to get your fill of vitamins and minerals," Jenkins said.

詹金斯說：“除了葉酸可能降低中風和心臟病風險外，沒有足夠數據表明服用補充劑對人體有益，因此最好還是從健康膳食中獲取你所需要的維生素和礦物質。”

"So far, no research on supplements has shown us anything better than healthy servings of less processed plant foods, including vegetables, fruits, and nuts."

“迄今爲止，沒有任何一項關於補充劑的研究顯示有任何藥物比攝入健康的輕度加工植物食品（包括蔬菜、水果和堅果）更好。”