Multivitamins: Are you wasting your money?

Jan 12, 2022
Dr Ross Walker looks into whether there are really any benefits to taking multivitamins. Source: Getty.

With prompts to get “Covid-19 ready” coming from multiple government agencies recently, the efficacy of whether multivitamins are helpful in fighting off, or even keeping infections away. Dr Ross Walker has done the legwork for us to work out if multivitamins are worth your money or not:


A study published in the online journal BMJ Open, which drew information from the 2012 National Health Interview Survey (NHIS) in the US, looked at the multivitamin ingestion of more than 21,000 people. Of these people, nearly 5,000 stated that they took a multivitamin regularly, whereas the remainder didn’t.

The regular multivitamin users were generally older, of higher income, female, college graduates, married and had private health insurance. They were questioned regarding a variety of parameters and on average they reported a 30 per cent superior level of overall health.

But when the researchers examined other variables, such as the need for help with routine daily activities, a variety of long-term health problems such as hypertension, diabetes, asthma or arthritis, or other conditions such as the amount of infections experienced per year, various forms of memory loss, musculoskeletal problems and conditions such as depression and anxiety, there was no difference between the multivitamin users and the non-users.

The conclusion of the survey was that the ingestion of multivitamins is purely placebo and, in reality, have no objective clinical benefit. Well, does that settle it then? Does that mean you’re wasting your money taking multivitamins or any other supplements for that matter? On the strength of this information, the answer is yes. But when you carefully analyse this report, it’s purely a survey of the individual’s subjective assessment of their own health. It’s not a randomised controlled trial to determine the benefits of multivitamins but a one-off questionnaire to see who did and who didn’t take multivitamins regularly and – from the questionnaire – make an assessment of their health status.

Another study, known as The Iowa Women’s Health Study, which was published in 2011, looked at almost 39,000 women, average age 62, for 19 years, and found no benefit from the regular ingestion of multivitamins. But, the largest epidemiological studies in the world, the Nurses’ Health Study and the Physicians’ Health Study, from Harvard, followed the health status of more than 180,000 health professionals, and found taking multivitamins did come with some benefits.

Over time, the studies have reviewed all parameters of health, including lifestyle, vitamin ingestion and medication use, with many sub studies of the trials performed and published in peer-reviewed journals. There are three components of these trials I would like to present in regard to multivitamin ingestion. The first looked at the male physicians in a randomised controlled fashion over a 10-year period and found those who were in the active treatment group taking a daily multivitamin for 10 years had an 8 per cent reduction in cataracts and common cancers.

When the observational data in the nurses was analysed at 15 years, there was a 75 per cent reduction in bowel cancer, a 25 per cent reduction in breast cancer, and a 23 per cent reduction in cardiovascular disease. When the data was analysed in the male physicians who had taken a multivitamin for 20 years compared with those who hadn’t, there was a 44 per cent reduction in cardiovascular disease purely by taking a multivitamin on a daily basis.

One of the major issues with any long-term medical therapy is compliance. It has been demonstrated in a number of studies that if any treatments are prescribed, whether these be pharmaceutical or supplemental, 50 per cent of people have stopped the therapy after 12 months. Therefore, a commitment to taking anything for 20 years or longer is a rather big ask, but clearly in people who have this commitment there’s a significant benefit.

Vitamin supplements of any form, in my opinion when analysing the data, have to be taken for a number of years before there are any clinical benefits, as clearly seen in the Harvard trials.

Drugs are strong and powerful with a potential for significant side effects. To use the example of statin drugs to lower cholesterol, there is generally a 20 to 30 per cent reduction in cardiovascular disease, typically studied in overweight people at high risk for heart disease. Also, in clinical practice, with a side effect rate anywhere between 10 to 20 per cent.

There has never been a study of statin therapy in people who also practised exquisite lifestyle principles, to see whether there are any added benefits from additional statin therapy over following healthy lifestyles. In my view, supplements will only work if you add them to a pre-existing healthy lifestyle, as seen from the Harvard data.

Another caveat here is that if you’re over 60 and have never taken a multivitamin, in my opinion, it’s probably too late to start. The reason is that multivitamins typically contain varying doses of B group vitamins, vitamin A, vitamin C, vitamin D and a variety of minerals and trace metals depending on the product.

I reckon that people should start taking multivitamins in their 30s or 40s and continue this practice for the rest of their lives. It’s in our 60s when we, more commonly, may be starting to develop cancers, and if you commence high-quality multivitamins it may feed into an early cancer and accelerate the growth. So, paradoxically, multivitamins probably prevent cancer if you take them for a very long period of time – starting early in your life – but may exacerbate problems if you start taking them too late.

Regardless, it’s never too late to start healthy lifestyle principles and the earlier you quit all addictions, develop a good-quality sleep habit, eat more natural food, have three to five hours of regular exercise on a weekly basis and, most importantly, generate happiness in your life and manage your stress, the more long-term benefits you will gain from this approach.

When you look at the data on healthy lifestyle practices, it’s four times more powerful than anything a doctor can offer you. It’s also my view that if you take high-quality supplements, of which a daily multivitamin is only one example, you will gain a reasonable benefit from doing so.

What are your thoughts on this? Do you take multivitamins?

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