In 2004, at the 5th Medical and Healthcare Industry and Pharmaceutical Machinery Expo held at Zhengzhou Zhongyuan International Expo Center, a woman passed a large advertisement of 28-multivitamin tablets from a pharmaceutical factory.sand wave
"Oh my God, I've spent so much money!When she saw a report entitled "It's not good for your health to take vitamin tablets," Su Mei, 33, exclaimed.For more than 10 years, she has been taking various vitamin tablets, in addition to one multivitamin tablet a day, plus one calcium tablet.Most of these were purchased by her friends from the United States, Canada, and Hong Kong.
"I always feel that my body is deficient in vitamins, so I supplement it a little every day to calm my mind."Sometimes I don't eat vegetables or fruits for a few days, so I comfort myself by saying that there are vitamin tablets anyway."Sue said.
But the scientific paper published in the authoritative medical journal "Annual of Internal Medicine" broke Su Mei's worship of vitamin tablets.On December 17, scientists analyzed a large comprehensive study of 500,000 people and found that taking vitamin supplements was almost invariably a waste of money and not good for health.
Analysts pointed out that this study is a major blow to the vitamin supplement market.In the United States, vitamin supplements are used by more than half the population.In 2010, the U.S. supplement market share reached $28 billion (about 170 billion yuan).Annual sales of British supplements are 650 million pounds (about 6.4 billion yuan), involving about a third of the country's population.
"China is relatively small, about 10% to 20%," said Chen Yuming, a professor at the School of Public Health at Sun Yat-sen University, a member of the Chinese Nutrition Society's Dietary Reference Intake revision panel.According to the statistics of the China Healthcare Association Market Industry Commission, in 2011, the market share of nutritional supplements in China was about 77 billion yuan.
But one of the authors, Edgar Miller, a researcher at Johns Hopkins University School of Medicine, told China Youth Daily: "Whether in the United States or China, vitamin supplementation is unnecessary for people with good nutrition.”
Some people claim that there are many nutritional deficiencies in our diet, but the fact is that we are usually completely nutritious.
Originally exposed to vitamin supplements, Su Mei was impressed by its advertising."It felt like old man's cactus, a few baskets of green leafy vegetables and fresh fruit cradled into a nail-sized vitamin.There are also advertisements that mold vitamin tablets into health shields, feeling that eating them can protect against various diseases."I remember Su Mei.She also bought it for her parents and supervised them to take it every day.
Many scientists are also fans of vitamins.Zheng Ji, a renowned biochemist and professor of nutrition at Nanjing University, insisted on taking 10,000 micrograms of retinol equivalent (ugRE) of vitamin A, 600 milligrams of vitamin C, 10 milligrams of vitamin B1 and 100 milligrams of vitamin E every day.Professor Ge Keyou, former chairman of the Chinese Nutrition Society, said in 2003 that he took 400 milligrams of vitamin C every day and has been sticking to it for 10 years.
Many people believe that as a basic element of maintaining the normal function of biological organisms, vitamins have the function of maintaining life and metabolism, can also delay aging, reduce cholesterol, help lose weight, expel toxins, prevent chronic diseases, and even prevent cancer.
But the results of numerous studies in recent years have led to near-subversive conclusions about the effects of taking vitamins.In 2007, the Journal of the American Medical Association published a study by multinational researchers that found a 4% increase in overdose mortality, a 7% increase in beta-carotene mortality, and a 16% increase in vitamin A mortality, and no evidence that vitamin C prolongs life.
The article, published today in the Annals of Internal Medicine, has been called a "decision" on vitamin supplements."In other words, no further research is needed.Lu Jie, a Chinese physician at the University of California Hospital, added.
The authors of the article are three from Johns Hopkins School of Medicine in the United States, one from Walker University School of Medicine in the United Kingdom, and one is a senior associate editor of the magazine, "all medical leaders."They came to the conclusion that three papers were published in the current issue of the journal.
The first study, a review of 27 clinical studies of vitamin supplements and disease prevention by the U.S. CDP system with more than 400,000 participants, confirmed that there was no evidence that vitamin supplements reduced any mortality or prevented cardiovascular disease or cancer.In addition, smokers who take beta-carotene alone have an increased risk of lung cancer.
Meanwhile, Harvard Medical School published a randomized double-blind controlled experiment in a large population.They followed 5,947 people over the age of 65 for 12 years, all of whom took daily multivitamins or placebos.The final conclusion is that long-term multivitamin use does not have any benefit for cognitive or language skills in older adults.
In the final study, the American Institute of Cardiopulmonary and Blood Diseases and the Center for Alternative Medicine looked at 1,708 patients who had experienced a heart attack.These people took multivitamins or placebos twice a day for up to five years, but more than half stopped taking them, making it difficult for the authors to draw any practical conclusions about the effectiveness of the vitamin.
Looking back at all of the current large-scale findings on vitamin supplements, the scientists say the evidence is strong: "These vitamins should not be used to prevent chronic diseases.”
"We don't advocate taking vitamin supplements, especially high-dose supplements that are often harmful."Some people claim that we have a lot of nutritional deficiencies in our diet, but in fact, we eat too much overall and our usual nutrition is completely adequate."”
Don't wait like Americans until vitamin tablets are flooded and reflect on this.
According to Lu Jie, Americans have been taking vitamin supplements for 30 or 40 years.He works and lives in Los Angeles, where many large supermarkets "have a wall full of supplements and health supplements, not thousands or hundreds of them, and are not expensive, a few dollars can eat for a year."
Nowadays, Americans are taking vitamin supplements to the point of "flooding."Some people joke that Americans' urine is the most expensive urine in the world because a lot of water-soluble vitamins are lost with urine.
As early as 40 years ago, Nobel laureate and biochemist Linus Pauling first advocated "large doses" of vitamin C, beneficial to health and anti-cancer.His daily dose was 18,000 milligrams (about 300 times the recommended daily intake).People followed suit, drug stores were in short supply, and by the mid-1970s, 50 million Americans had followed Pauling's advice, which vitamin producers called the Linus Pauling Effect.
In May 1980, Pauling was interviewed at Oregon State University.When asked if there were any side effects from long-term use of grams of vitamin C, Pauling responded quickly and decisively: "There will be no side effects."Seven months later, his wife died of stomach cancer.Pauling died of prostate cancer in 1994.Today, a large number of scientific examples prove that vitamin C is not effective in treating colds, preventing cancer, and taking it in large quantities can also bring side effects.
"China has also been popular for more than a decade.Chen Yuming told the China Youth Daily reporter.Many pharmacies in Beijing have opened up specialized best-selling drug sections, just like the "best-selling book counters" in bookstores.The exquisite packaging is printed with a confident smile on the face of the endorsing star, and the bottle contains yellow transparent pills.Wearing a white coat, the concierge who calls himself a "doctor" told reporters: "These nutrients are very popular.”
Lu Jie expressed concern about this: "Like China, we should face up to this fact before the situation has completely expanded, rather than saying that if you look at the Americans like this, I will eat and reflect on this problem."”
Yu Kang, a clinical nutritionist at Peking Union Hospital, pointed out that the study of the Annals of Internal Medicine is mainly based on European and American people, and unlike Chinese people, it cannot be used directly.
This is also the view of some domestic dietitians.National level public nutritionist Wang Leijun is one of them.In Wang Leijun's view, China's cooking methods are more fried, and vitamins will be greatly lost in the process; then, for example, haze weather, will cause vitamin D deficiency in the human body.Because of the teaching task, often feel tired and uncomfortable, Wang Leijun will take a vitamin supplement every day.He thinks it's hard to get enough vitamins in fruits and vegetables every day.
At the 11th National Nutrition Science Conference of the Chinese Nutrition Society held in Hangzhou in May this year, the reference intake of vitamin C for adults was adjusted from 100 mg to 200 mg per day, with an upper limit of 1,000 mg.The recommended daily intake of vitamin A is 800 ugRE (male) and 700 ugRE (female).Chen Yuming said that this amount is taken into account the amount of vegetables lost in the cooking process.