Should you be taking a vitamin supplement?

Should you be taking a vitamin supplement?

According to the latest National Health Survey, at least 29% of Australians actively take at least one dietary supplement. Of these, 50% of people take more than one supplement daily.

It’s no wonder things are looking good for the complementary medicine industry, with $4.7 billion revenue in 2016 (up from $3.5 billion in 2014).

Walking down the supermarket isles, you’ll notice there is a supplement for nearly everything that ails you – cold sores, poor immunity, underwhelming sports performance, bad skin, depression or just being a woman. It makes a person feel like, well, something might be wrong with them. And that perhaps, these problems can be fixed by this brightly coloured, scientific-looking tub of pills.

I’m in fairly good health. But, I mean, when I really think about it – I could probably feel better than I currently do. And it’s not like I want to develop cancer or heart disease. Perhaps a supplement could help me?

There is this notion that supplements might fill a nutritional gap, and that we’re better off taking them just in case we aren’t getting all of the vitamins and minerals we need from our diets. Most of us are unaware that these supplements may be causing us more harm than good.

Antioxidants – good or bad?

Antioxidants are thought to combat free radicals; chemicals that damage the cells in your body and cause them to become unstable and potentially cancerous. There is an enormous body of evidence supporting the endless health benefits of a diet high in plant-based foods, foods that offer us an abundance of antioxidants.

Surprisingly, the same is not true of antioxidant supplements. In fact, there have been a number of studies suggesting that antioxidant supplements may increase a person’s risk of cancer and reduce their lifespan. 

Lung cancer is one example of this. A high fruit and vegetable intake is strongly correlated with a reduced risk of lung cancer.

Researchers theorised that this might be due to the action of beta-carotene, an antioxidant nutrient in many vegetables. Inspired by this, scientists gave a whole lot of smokers a beta-carotene supplement, imagining it would do wonders for cancer. Unfortunately, the beta carotene supplement ended up increasing the development of lung cancer in these smokers.

In 2007, another study conducted an analysis of 68 randomized trials of any antioxidant supplements. This study showed significant increase in risk of death in the groups taking the supplements compared to the groups taking placebo pills.

What’s the story with vitamins?

I read through endless systematic reviews and meta-analyses for this article.

Repeatedly, I found that multivitamin supplements failed to find any benefit of improved life-expectancy or disease outcomes.

Most vitamins are water soluble and, when not required by the body, are excreted via urine. Some vitamins, however, are fat soluble – which means they linger around in the body. Fat soluble vitamins include vitamin K, A, D or E.

These can be quite damaging if consumed in excess, because we can’t get rid of them so easily. For example, too much vitamin A can cause liver damage and too much vitamin D leads to fatigue, tinnitus and heart arrhythmias.

These fat soluble vitamins, along with antioxidant extracts, are found in many multivitamins. With the inefficacy, potential risks, poor quality control and high cost - I can’t help but think, what is the point in multivitamins? It’s quite easy to get all that you need from your diet. I would suggest you look at incorporating more whole foods if you’re worried about not getting enough nutrients.

Vitamin C for the common cold?

It’s not unusual for people to take vitamin C when they’re coming down with a cold. Interestingly, most studies have shown that vitamin C supplements are completely ineffective at reducing the length or severity of a cold. It’s also worth noting that vitamin C, taken long-term, is associated with an increased risk of kidney stones.

Chicken soup, on the other hand, has been scientifically proven to help to clear blocked noses, fight infection and help with recovery from respiratory tract infections. It also makes people with colds reportedly feel better.

What about herbal supplements?

There are a vast range of ‘natural’ supplements on the market. Often consumers tend to feel more trusting of these natural remedies, but sadly these too have been associated with a number of risks. Herbal supplements have been linked to 6 organ transplants since 2011. There is no organisation that effectively monitors the content of these supplements, nor the truth of the claims made on the label. Here are a few examples of this:

  • St Johns Wort is supposed to help with depression but has been shown to be ineffective at this, and also increases the side-effects of prescribed anti-depressant medication.

  • Echinacea is a natural cold remedy – most studies indicate this has no effect in reducing colds and can cause gastrointestinal problems, allergic reactions, and increased asthma symptoms.

  • Cranberry extract – used to treat urinary tract infections, has shown to be completely ineffective in supplement form.

Food vs. Pills

There are a few key differences between food and supplements. Supplements contain a single, or several nutrients synthesised or extracted from food. Food contains a huge array of nutrients – nutrients that exist in perfect balance, in combination with fibre and other beneficial elements that are not found in pills.  

Let’s not forget – the nutrients in food interact with one another, working together, leading to specific biochemical reactions and changes in the body. Extracting one of these chemicals and putting it back into the body will not necessarily have the desired effect.

When are supplements useful?

Vitamins may be useful in the following circumstances:

  1. If you have been diagnosed with a deficiency and/or have a condition that prevents you from absorbing nutrients from food (e.g. coeliac disease).

  2. If you’re following a vegan diet, you may want to check your vitamin B12 levels. Supplementation will be required if you’re deficient, as this vitamin can only be found in animal-based foods.

  3. If you’re trying to get pregnant, folic acid supplementation can prevent neural tube defects such as spina bifida. This needs to be taken pre-pregnancy, as by the time you realise you’re pregnant, it may be too late.

  4. If you have limited exposure to sunlight, you may need to supplement with vitamin D - a common deficiency in night workers. If you work indoors all day, make time to go outdoors for 10-20 minutes each day, exposing your arms and neck. Get your levels checked by your doctor before you begin supplementing, as there are risks attached to this one.

If you don’t fall into the above categories, and are generally a healthy individual, I highly recommend avoiding dietary supplements altogether. If you want to be in better health and prevent disease, there is plenty of evidence to suggest you can do this by improving your diet and eating more plant-based foods; wholegrains, fruits and vegetables. 

These are foods that we know most people don’t eat enough of in their diet, and these are the foods known to prolong your lifespan and prevent disease. You may have heard it a number of times before, and this might not make me $4.7 billion, but it’s science, baby.

Lucy x


Australian Bureau of Statistics (checked in February, 2018)

Greenwald, P., Anderson, D., Nelson, S. A., & Taylor, P. R. (2007). Clinical trials of vitamin and mineral supplements for cancer prevention. The American journal of clinical nutrition85(1), 314S-317S.

Miller, E. R., Pastor-Barriuso, R., Dalal, D., Riemersma, R. A., Appel, L. J., & Guallar, E. (2005). Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Annals of internal medicine142(1), 37-46. 

Schwingshackl, L., Boeing, H., Stelmach-Mardas, M., Gottschald, M., Dietrich, S., Hoffmann, G., & Chaimani, A. (2017). Dietary supplements and risk of cause-specific death, cardiovascular disease, and cancer: a systematic review and meta-analysis of primary prevention trials. Advances in Nutrition8(1), 27-39.

Bjelakovic, G., Nikolova, D., Gluud, L. L., Simonetti, R. G., & Gluud, C. (2015). Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Sao Paulo Medical Journal133(2), 164-165. 

Watkins, M. L., Erickson, J. D., Thun, M. J., Mulinare, J., & Heath Jr, C. W. (2000). Multivitamin use and mortality in a large prospective study. American journal of epidemiology152(2), 149-162.

Macpherson, H., Pipingas, A., & Pase, M. P. (2012). Multivitamin-multimineral supplementation and mortality: a meta-analysis of randomized controlled trials. The American journal of clinical nutrition97(2), 437-444.

Linde, K., Barrett, B., Bauer, R., Melchart, D., & Woelkart, K. (2006). Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews, (1).

Hemilä, H., & Chalker, E. (2013). Vitamin C for preventing and treating the common cold. Cochrane database of systematic reviews, (1).

Bjelakovic, G., Nikolova, D., Gluud, L. L., Simonetti, R. G., & Gluud, C. (2007). Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. Jama297(8), 842-857.

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