揭開維生素的神祕面紗:你將選擇服用什麼

We spend a fortune on vitamins and painkillers in the UK; about ?362m on each a year. And a new report by industry analysts shows that, for the first time in a decade, sales of vitamins have risen above those of painkillers. Theories accounting for the growing demand for supplements include our hectic modern lifestyle, awareness of healthy living and an ageing population. This implies that we have no time to eat real food, think we need to boost vitamin intake to be healthy and that the elderly are suckers for products promising pain-free joints and eternal youth. But, even if we don't believe all the marketing hype, are vitamin and mineral supplements good for us?

在英國,我們在維生素和止痛藥上的花費大約是每年3.62億英鎊。而業內分析師十年來第一次給出的最新報告顯示，維生素的銷售已經超過止痛藥。理論上滿足了日益增長的需求包括我們繁忙的現代生活形式、健康生活的意識和人口老齡化。這意味着我們沒有時間吃真正的食物，認爲我們需要增加維生素的攝入，爲了健康和青春永駐。老年人使用無痛苦關節的產品，而且老年人的產品市場很有前景，比如無痛苦的關節和青春永駐類產品。然而即使我們不相信所有市場營銷的炒作，但是維生素和礦物質的補充劑對我們有益嗎？

Many of us will have lowish vitamin D levels after a long winter and the health implications are unclear. NHS Choices recommends that everyone over 65 and people who don't get much sun take a small daily supplement. Pregnant women and people whose diet is very restricted (such as alcoholics and some vegans) need expert dietary advice. Some people can't absorb vitamins from food because of gut surgery or damage from conditions such as Crohn's disease. Vitamin deficiencies can result in serious health problems such as rickets (vitamin D), scurvy (vitamin C) or severe anaemia (B12 and folate). A simple blood test organised by your GP will diagnose most of these.

漫長的冬季後，我們很多人體內維生素D含量都很低，對健康的影響目前還不清楚。英國國家醫療服務體系建議， 65歲以上的人如沒有曬足夠的太陽，每個人應每天攝取一小片。孕婦和節食的人除外（如酗酒和一些素食主義者）需要專家的飲食建議。有些人由於腸道手術或條件損害如克羅恩病不能從食物中吸收維生素。維生素缺乏會導致嚴重的健康問題，如佝僂病（維生素D），壞血病（維生素C）或嚴重的貧血（B12和葉酸）。家庭醫生通過一個簡單的血液組織測試就能診斷大部分的疾病。

If you're well with no symptoms and a reasonable diet, it's very unlikely that you've got a significant vitamin deficiency. The question is whether taking them will do you any harm. The small print on the tub tells you the recommended daily allowance of each active ingredient. If you stick to that, you should be OK. Vitamins B and C are water soluble, so any excess ends up in your urine. However, vitamins A, D, E and K are fat-soluble, so excess is stored in fat and levels can build up. High levels of vitamin A can be toxic.

如果你沒有症狀，飲食也很好，你得維生素缺乏症幾乎是不可能的。現在的問題是服用維生素是否對你有任何傷害。在藥瓶裏面的小字條上告訴你每天的有效攝食量。如果你按上面堅持服用就可以，維生素B和C是水溶性的，任何超量攝入最後都會從尿液中排除。然而維生素A、D、E和K是脂溶性的，過量攝入會儲存在脂肪和堆積起來，維生素A含量高可能是有毒的。