The Potential Danger of Multivitamins

Multivitamins are Big Business

A staggering number of people regularly use vitamin supplements. In fact, estimates suggest that over a half of all Americans take some sort of vitamin or multivitamin supplement every day. The industry is worth billions globally with no signs of slowing down. But do people really need to be taking vitamins for their health and could they actually be doing more harm than good?

Many people have taken supplementary vitamins since childhood and presumably never question the reason why. A little digging into the research related to the use of supplementary vitamins yields some surprising results.

Now, I am sure you are aware that there are few fields more contentious than nutrition. It seems that one day we are told that something is good for you only for a new study to tell you the opposite is true. For years we were told that cow’s milk was good for you only for a recent report to inform us it was not the case. Does coffee take years from your life or can it provide you with a decent health boost?

Are Vitamin and Multivitamin Supplements good for you?

Not surprisingly, the answer is unclear. For certain people who are deficient in a vitamin then the answer is probably yes. However, when it comes to healthy people who are getting sufficient vitamins from their food then the answer is almost definitely no.

Countless published studies have consistently suggested that vitamin supplements do not prevent disease and illness. There are even some recent studies suggesting that they could even contribute to cancer, heart disease and mortality.

Why do So Many People Take Multivitamins?

In 2013, researchers at the Office of Dietary Supplements at the Office of Dietary Supplements at the National Institutes of Health set out to find the answer. The study collected data from around 12000 American adults who took part in the survey. (1)

They found that people took multivitamins for several different reasons:

• 45% of people that took multivitamins did so believing it would have a beneficial impact on their health.
• 33% took a multivitamin in order to maintain their good health.
• Only 23% took multivitamins based on their doctor’s recommendation. When doctors recommend a supplement. It is not usually a multivitamin and is usually for a specific condition. They recommend calcium for better bone health (24%) but also for overall health and well being (18%). Fish oil is often recommended to improve heart health (12%) or to supplement the diet.

According to the author of the report, there is a clear role for certain dietary supplements for some people, Folic acid, for example, is important for pregnant women to reduce the risk of birth defects. Vitamin D and calcium both play a crucial role in bone strength and health for people who need it.

However, when it comes to multivitamins, there is no firm evidence that they really do benefit the health. Two recent studies published a few months apart in 2012 seem to illustrate this ongoing debate fairly well.

One study found that multivitamins did nothing to help reduce the risk of heart attacks, stroke or heart disease such as atherosclerosis. (2)

On the other hand, another study published in the same year and same journal found that men who used multivitamins each day for a few years reduced their risk of developing cancer by a small but not significant amount. (3)

Vitamins are of course necessary to ensure good health and there is no doubt that prolonged deficiency in vitamins can result in various diseases and sicknesses. However, the main question that needs to be answered is whether multivitamin and vitamin supplements are needed for the vast majority of healthy people. Another important question is whether taking too many supplementary vitamins can have the opposite effect.

The Potential Dangers of Taking Multivitamins

Multivitamins May Increase the Risk of Cancer

Although multivitamins and other dietary supplements are believed by most people to improve health, the opposite could be true.

At the annual meeting of the American Association for Cancer Research in 2015, Tim Byers an investigator and associate director with the Cancer Center at the University of Colorado gave details of recent research.

The research which was first published in 2012 indicates that mutivitamins and other supplements available over the counter might actually cause the risk of cancer to increase when they are taken in amounts above the recommended daily dose. (4)

The research began two decades ago when it was observed that people who ate more fresh fruit and vegetables were less prone to developing cancer. Researchers wanted to examine whether taking supplementary minerals and vitamins could reduce the risk of cancer even further.

Thousands of people taking daily vitamins and other dietary supplements were tested over ten year period. The results were certainly not what the researchers had expected.

They found that not only were the dietary supplements people were taking not especially beneficial to their health but cancer was more prevalent in people taking vitamins.

One particular trial found that beta carotene supplements taken in excess of the recommended dose led to a 20% increase in the risk of lung cancer and also heart disease.

Mr Byers did go on to say that people should not be scared of taking mutivitamins and mineral supplements. According to Byers if they are taken in the correct doses, multivitamins can be beneficial but he went on to say there was no substitute for good, healthy, nutritional food.

The vast majority of people should be able to get their recommended daily doses of minerals and vitamins from their diets which negates the need to take supplements.

‘At the end of the day, we have found that extra vitamins and minerals do more harm than good’ said Mr Byers (4)

Too Much of a Good Thing

When you take supplementary vitamins, you are often taking many times more than the recommended dose and in some cases up to 100 times more than is required.

Experts have often repeated the concern that putting too many supplementary vitamins or minerals into the body can have adverse effects. This fact has been borne out by research. Two separate meta-analyses have been done involving data on over 400,000 patients. Both looked at the effects of the regular use of multivitamins and found that people who took the supplements daily had an increased rate of mortality.

Another study published in 2007 indicated that females who took daily multivitamin supplements made up of vitamins C and E, beta-carotene, zinc and selenium had an increased risk of developing cancer of the skin.

You May Not Need Supplementary Vitamins

As long as you are consuming the recommended amount of vitamins and minerals from eating healthy food like fruit, vegetables, protein, dairy and cereal, there appears to be little benefit from multivitamins or individual supplements.

Who Should Take Multivitamins?

We have already mentioned that large scale trials have found they do not improve the health of an average person.
The people who may need to take multivitamins include pregnant women, nursing mothers, people on strict calorie controlled diets or diets that forgo certain food groups such as low carb diets. Others that can benefit are people with medical complaints that adversely affect food absorption and digestion.

(1) https://consumer.healthday.com/cancer-information-5/mis-cancer-news-102/with-benefits-unproven-why-do-millions-of-americans-take-multivitamins-673173.html
(2) http://jamanetwork.com/journals/jama/fullarticle/1389615
(3) http://jamanetwork.com/journals/jama/fullarticle/1380451
(4) https://www.ncbi.nlm.nih.gov/pubmed/22534785