This is official. Vitamins are not good for health

This transcript has been edited for accuracy.

you welcome Impact FactorComment on a new medical study, your weekly dose. I am Dr. F. Perry Wilson of Yale Medical School.

Vitamins. If you’re like most American adults, you’ve recently taken a vitamin or supplement. Over-the-counter sales of these products in this country exceed $ 30 billion a year. It’s more than the statins market – and vitamins aren’t covered by insurance.

For a $ 30 billion market, there must be some compelling evidence that vitamin supplements can help improve health, right?

To date, in the most thorough meta-analysis, researchers from Kaiser-Permanent have concluded that the numbers from almost every randomized trial of vitamin supplements in adults are largely ineffective.

Or as nephrology says: Vitamins make urine more expensive.

As many of you know, the U.S. Preventive Services Working Group (USPSTF) provides the American people with evidence-based recommendations for a variety of health behaviors, from aspirin to lung cancer screening for basic prevention.

The USPSTF instructed researchers to update data on vitamin supplementation with two important outcomes: cancer and cardiovascular mortality. Why vitamins? Because the observations are accurate and reliable. People with vitamin deficiencies are more prone to these side effects.

Even in the range of deficiencies of some vitamins, people with low levels are at higher risk of cancer and cardiovascular disease. If low levels are associated with poor results and supplements prevent vitamin deficiencies, supplements can improve those results.

The researchers identified 87 randomized controlled trials of adults who were assessed for at least one vitamin or multivitamin. Note: This was a study of the general population, not a study of people with known vitamin deficiencies. Results should not necessarily be generalized to diseases that have known defects or are caused by defects.

Lots of vitamins, so there’s a lot to cover, but I’ll focus on some highlights.

Of the many potential links between vitamins and results, only one – the link between multivitamins and cancer – showed some signs of benefit.

This is a little frustrating because “multivitamins” can mean a lot. There have been nine randomized trials evaluating “multivitamins” that show this effect when combined, but the specific types of multivitamins were different, ranging from a special antioxidant cocktail to Centrum Silver. No, I don’t know what multivitamin you should take.

To be honest, the effect is not very effective: the relative reduction in cancer is 7%. Relative risks, on the other hand, tend to overestimate the magnitude of the effect. In absolute terms, multivitamins reduce cancer by 0.2%. This means that 500 people need to be treated with multivitamins to prevent a single case of cancer.

And although these studies did not register patients with specific vitamin deficiencies, some of those registered may have had them. What we are seeing is a less population effect based on the benefit of a small number of people who are really vitamin deficient.

And this is actually the best result of the whole study, if you are a vitamin lover.

Analysis of individual vitamins – beta-carotene, vitamin A, vitamin E, vitamin D (with 32 randomized trials) and calcium supplements – showed significant benefits in terms of cardiovascular disease or cancer. They just don’t seem to do much.

So why is the act of taking a vitamin so interesting? Why do most of us continue to take pills every day, even knowing that the data does not support it? I think there are a couple of reasons.

First, we must admit that vitamins are generally very cheap and the side effects are very low. They do not cause dizziness, dizziness, tachycardia or fatigue. They don’t feel much.

Given the low risk, there is something of a Pascal bet here. Of course, it may not help, but they seem to do no harm, so why not take them.

Yes, in fact, they can do a little damage. The authors were also able to analyze the adverse effects of all vitamin tests, but only to assess their harm and also Includes observational studies. This may seem unfair – to evaluate the benefits not only through randomized trials, but also through randomized trials and observations. However, in my opinion, one-sidedness in observational studies favors vitamins, given the “healthy user effect”. The idea is that people who choose to take these vitamins will choose a healthier lifestyle, so if you notice any harm in taking the vitamin under observation, you may want to pay attention to it.

Significant findings for damage analysis The use of vitamin A increases the risk of hip fractures, the use of vitamin E increases the risk of hemorrhagic stroke, and the use of vitamin C or calcium increases the risk of kidney stones.

Why are observational data showing low vitamin levels associated with poor results, and randomized test data for supplements being so weak? This is a classic mess. In fact, healthy people have higher levels of vitamins, while healthy people are less likely to have cardiovascular disease and cancer. Vitamins are not an indicator of health, but an indicator of overall health.

But to be fair, there is no harm in taking a vitamin every day. Here we must not lose sight of the invaluable value of ritual. While taking a vitamin is a small task, it is an act of self-care – a moment we take for ourselves and for ourselves – to try to stay healthy. A short positive moment in the morning may not reduce heart attacks or cancer, but it can still benefit.

F. Perry Wilson, MD, MSCE, Associate Professor of Medicine and Director of Yale Clinical and Translator Research Accelerator. His research work can be found at the Huffington Post, NPR and here at Medscape. and on Twitter @fperrywilson and has a repository of its communications activities at

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