手機版
What you need, and how to get it
你需要哪些維生素，如何科學地進補
By Amanda Gardner 阿曼達•加德納
Vitamins and minerals are essential to any diet, and research suggests they may help prevent cancer and heart disease, not to mention other health problems. But reality check: Many studies have been conducted on vitamin-containing food, but not necessarily supplements.
維生素和礦物質是任何飲食中不可或缺的成分。研究表明，維生素和礦物質可能有利于預防癌癥和心臟病，以及很多其它疾病。但事實是，圍繞富含維生素的食品進行的很多研究表明不必一定進補。
In fact, if you eat a diet rich in fruits, vegetables, and fortified food, you're probably getting all you need. But supplements do offer an easy, just-in-case form of health insurance.
事實上，如果你的日常飲食含有豐富的水果、蔬菜和強化食品，你的身體可能已經獲取所需維生素的數量。但是，補品的確很方便地為您的健康增加了一道保險。
Do you need them? Here's a quick guide to beneficial nutrients and what they can do for you.
你真的需要它們嗎？以下是關于一些營養成分及其作用的一個簡明指南。
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Beta-caroteneβ-胡蘿卜素
Found in carrots, sweet potatoes, and green peppers, among other foods, this antioxidant is converted in the body to vitamin A and is important for healthy vision, a functioning immune system, and good skin. But the evidence isn't really there to recommend it for staving off cancer. In fact, a 2004 study found that supplements may actually raise the risk of lung cancer in smokers.
β-胡蘿卜素存在胡蘿卜、紅薯、青椒及其它食物中，它是一種抗氧化劑，被人體吸收后轉化成維生素A，有利于視力健康、增強身體免疫系統的功能以及改善皮膚。但是，并沒有證據足夠證明它能預防癌癥。事實上，一項2004年的研究發現，藥進補β-胡蘿卜素實際上增加了吸煙者罹患肺癌的風險。
Bottom line: Skip the supplements if you're a smoker, and try to get your beta-carotene from fruits and veggies, whether you smoke or not.
忠告：如果你吸煙，就不要采取藥物進補β-胡蘿卜素的方式。當然，不管你吸不吸煙，最好都盡量從水果和蔬菜中直接獲取所需β-胡蘿卜素。
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Calcium 鈣
Our bodies need calcium—mostly found in dairy products like milk, yogurt, and cheese—to maintain healthy bones and prevent osteoporosis.
我們的身體需要鈣——它們主要存在乳制品中，如牛奶、酸奶和奶酪——來維持骨骼健康和預防骨質疏松癥。
Bottom line: Supplements aren't a bad idea if you hate dairy (and can eat only so much kale and canned sardines), but you may want to skip them if you're prone to kidney stones or are a female over 70. A 2010 report linked supplements to heart-attack risk in older postmenopausal women. If you decide to go with supplements, don't take more than 500 milligrams at a time, and pair them with vitamin D to improve calcium absorption.
忠告：如果你不喜歡奶制品（并且只能吃大量芥藍菜和罐裝沙丁魚），那么通過藥物補鈣的主意并不差，但是，如果你是腎結石體質或70歲以上的女性，也許你就不能考慮這種方式。2010年的一項報告表明，補鈣藥物與絕經后的老年婦女心臟病風險增加有關聯。如果你決意服用補鈣藥品，一次不要超過500毫克，與維生素D搭配服用，更有利于鈣的吸收。
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Folic acid 葉酸
Folic acid, which prevents neural tube defects such as spina bifida in babies, is found in fortified breakfast cereal, dark green vegetables, legumes, citrus fruit juice, bread, and pasta.
葉酸，可以預防神經缺陷類疾病，如胎兒的脊骨裂，在強化早餐麥片、深綠色蔬菜、豆類、柑橘果汁、面包和面食里均含有。
Bottom line: Getting 400 micrograms a day of this B vitamin, and 600 if you are pregnant or lactating, is a no-brainer. That amount should come from food, supplements, or both, according to the National Institutes of Health (NIH). The jury's still out as to whether folate combats cancer, heart disease, or mental illness.
忠告：每天需要補充400毫克的這種B族維生素，如果你懷孕了或在哺乳期內，補充600毫克是很明智的。按照國家衛生研究院（NIH）的說法，你應該通過食物、保健品，或者結合以上兩種方式來獲取所需葉酸量。至于葉酸是否有抗癌、防治心臟病和精神疾病的作用，還有待分曉。
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Iron 鐵
You may not love the foods highest in iron (liver and other organ meats), but the mineral is critical for the proper functioning of red blood cells and, therefore, the prevention of anemia.
你也許不喜歡吃富含鐵的食物（肝臟類食物或其它內臟類食物），但是鐵對于紅細胞功能的正常動作至關重要，可以預防貧血。
Bottom line: Try to get iron from dietary sources, which also include lean meats, seafood, nuts, and green, leafy vegetables. However, you may need a supplement if you're anemic, or your doctor might prescribe them before surgery, says Jessica Anderson, a registered dietitian with the Coastal Bend Health Education Center, at the Texas A&M Health Science Center, in Corpus Christi. Women, especially those who are pregnant or menstruating, might also benefit.
忠告：盡量從飲食中獲取鐵，如瘦肉、海產品、堅果和多葉的綠色蔬菜。但是，如果你貧血，你就需要通過服用補鐵藥物來進補了，或者在手術前，醫生也可能會開這類藥給你，杰西卡.安德森說。她是科珀斯克里斯蒂市，德克薩斯A&M 健康科學中心的海岸健康教育中心的注冊營養專家。口服補鐵藥物特別對懷孕或處于生理周期的女人是有益的。
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Multivitamin 復合維生素
There is limited evidence that multivitamins may help prevent breast cancer, and an NIH panel in 2006 wasn't convinced that popping the pills was worth it. Neither is the Agency for Healthcare Research and Quality, which said the only benefit could be to reduce cancer risk in people with poor nutrition. And a large 2009 study failed to find any beneficial effects of the vitamins for cancer or deaths among postmenopausal women.
目前，支持復合維生素可能預防乳癌的證據很有限，2006年，國家健康協會（NIH）專項研究小組研究表明，并不確定每天把復合維生素藥丸丟到口中有什么價值。國家衛生健康研究與質量機構也沒什么證據，他們說，復合維生素僅對營養不良人們來說，有降低罹患癌癥的風險。在2009年進行的一次大規模的調查研究，并沒有發現，復合維生素對降低絕經后婦女罹患癌癥和死亡風險有什么實際效果。
Bottom line: Multivitamins aren't a bad idea if "you're on the go," Anderson says. "But don't expect major lifesaving benefits."
忠告：如果你的身體已“衰敗垂危”，進補復合維生素是一個好主意，安德森說。“但可別把它當成你的救命稻草。”
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Potassium 鉀
Potassium can lower blood pressure, even out irregular heart rhythms, and counteract the effects of too much sodium. It's found in bananas, raisins, leafy greens, oranges, and milk.
鉀可以降低血壓，甚至可以調節心律和消解食用過多鈉鹽而產生的副作用。在香蕉、葡萄干、多葉綠色蔬菜、柑橘和牛奶里均含有。
Bottom line: Consider a supplement if you're taking potassium-depleting diuretics for a heart condition, or if you're African American, a group that's at higher risk for hypertension and heart disease. Keep in mind that too much potassium can be harmful to older people and people with kidney disease.
忠告：如果你因心臟不好在服用耗鉀利尿劑，或者你是非裔美國人——罹患高血壓和心臟疾病風險較高的群體，需要要考慮一下藥物補鉀。謹記，補鉀過多對老年人和腎臟有病的人有害。
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Selenium 硒
The body needs only small amounts of this antioxidant, found in meats, seafood, eggs, and bread. A study found that taking 200 micrograms daily reduced the risk of prostate, lung, and colorectal cancers, but other studies have been "complete flops," Anderson says. That includes a 2011 analysis.
我們的身體只需少量這種抗氧化劑，在肉類、海產品、雞蛋和面包里均含有。一項研究表明，每天攝取200毫克的硒，會降低患前列腺癌、肺癌和直腸癌的風險，但是，包括2011年在內的其它一些研究分析，均以“失敗告吹”，并沒有得出以上結論，安德森說。
Bottom line: Don't count on selenium to lower your chances of getting or dying from cancer. It's likely you're getting enough from food sources, anyway.
忠告：不要指望硒會降低你患癌癥和死于癌癥的風險。總之，你基本上能夠從日常食物中獲取足夠量的硒。
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Vitamin C 維生素C
This much-touted cure-all, found in citrus fruits, berries, broccoli, and green peppers, just doesn't make the grade when it comes to common-cold prevention. One study did suggest that taking vitamin C regularly might reduce the length of a cold by a day. 這種倍受吹捧的百寶丹，存在柑橘類水果、莓果、花椰菜和青椒里，并不能夠成功地預防感冒。但是有一項研究的確表明，定期地服用維生素C可以縮短感冒的病程。
Bottom line: Try to get enough vitamin C through your diet. It's fine to take a supplement, especially if you're a smoker or nonsmoker who is often exposed to secondhand smoke. But there seems to be little point in upping your intake to combat sniffling and coughing.
忠告：盡量通過飲食中獲取足夠的維生素C。尤其是如果你吸煙，或雖然你不吸煙但經常被動吸二手煙，通過藥物進補維生素C也沒關系，但是增加進補量對于防治感冒流鼻涕和咳嗽不會有什么效果。
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Vitamin D 維生素D
Vitamin D, which helps the body absorb calcium, is necessary for bone health. It's mostly accessible through sun exposure, not food. Too little vitamin D can contribute to osteoporosis and rickets in children. Some evidence suggests that the vitamin may reduce the risk of type 1 and 2 diabetes and multiple sclerosis, but the jury's still out on these benefits.
維生素D促進身體對鈣的吸收，是骨骼強健的必要物質。主要是通過曬太陽而不是從食物中獲取。體內維生素D含量過少，可能引發骨質疏松癥和兒童的佝僂病。有證據表明，此種維生素可以降低1型、2型糖尿病和腦脊髓多發性硬化疾病的風險，但是還有待于論證。
Bottom line: Even though very little sun is needed to get your quota of vitamin D, and some foods are fortified with it, deficiencies aren't unusual. Supplements might be a good idea, especially if you don't have much sun exposure, are over 50, or have dark skin.
忠告：非常少量的陽光就能讓你獲得所需的維生素D，而且一些食物里也加添加了這種營養物質，所以，維生素D缺乏癥并不常見。但是，如果你不經常曬太陽且年過50或膚色暗沉，藥物進充維生素D也許是一個好辦法。
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Vitamin E 維生素E
Once upon a time, researchers thought this antioxidant could protect the heart, but a large trial published in 2005 found that 600 international units (IUs) every other day neither prevented cancer nor lowered the risk of heart attack or stroke in middle-aged and older women. (More recently, a 2008 study found no benefit of 400 IUs every other day in middle-aged and older men.)
研究人員曾經一度認為，這種抗氧化劑可以保護我們的心臟。但是在2005年公布的一次大規模試驗表明，每兩天服用一次600（國際）單位劑量的維生素E即不能防癌，也不會降低中年或老年婦女心臟病發作和中風的風險。（近些時間，一項2008年的調查研究發現，中年人和老年人每兩天服用一次400（國際）單位劑量維生素E，也沒發現有任何好處）
Bottom line: Forget the supplements and get your vitamin E from food (oils like safflower, peanuts, eggs, fortified cereals, fruits, and green, leafy vegetables). Bear in mind that cooking and storing foods with vitamin E can reduce the amount you're getting.
忠告：不要使用藥物進補，從食物中直接獲取維生素E（如紅花籽油、花生油、雞蛋、強化麥片、水果和葉類綠色蔬菜）。謹記，含有維生素E的食物經烹調或者儲存后，會降低維生素的含量。
相關閱讀：復合維他命---其實你不一定需要
