Pills, tablets and capsules of various shapes and colours.
Research report
6 March 2020

Supplements and what the labels don’t tell you

Even the most popular vitamin supplements have little scientific backing.

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Paul B.
14 Aug 2021

When writing articles on nutritional supplements I believe the quality of the information shared could be much improved with the support of GPs who are trained to use nutritional supplements, in their work with patients in the community, and who are also trained in evidence-based medicine. These are a relatively small group of GPs who have done a post-graduate study with the Australian College of Nutritional and Environmental Medicine(ACNEM), or a similar organisation. These GPs will be able to give you access to the evidence and thinking that they use when consulting with patients. I recommend Dr Tim Ewer in Mapua (South Island) and Dr Damian Wojcik Whangarei (North Island) as contacts for these doctors.

Brendan C.
14 Apr 2020
The case (or not) for taking vitamins..

Like we see with the political situation around the word faced with holding a belief and evidence people will do mental gymnastics to avoid changing their beliefs hence most of the comments here.

The history of vitamin supplementation goes back 100 years or so and accelerated further in a 1970's study showing great benefits. For decades after people couldn't replicate the findings and finally in large (50,000 western world people) studies conducted over long time periods in late 1990's and early 2000's in Germany and other places no benefits were found. By that time it was to late as people were making billions of $$ and the rest is history.

They are taken for many reasons. Some people need them however for some people they can be toxic e.g. my uncle who died of haemochromatosis. Most is to do with the psychology - people want to feel in control; they want to feel like they are making a positive difference and most of all people love simple solutions, silver bullets that will make things all ok. A simple pill has that in spades.

If you ask people why they don't randomly take say antibiotics or other medicine without a diagnosis they'd look at you like you are mad but without detailed blood tests they pop a vitamin pill. I did get detailed blood tests which was interesting as it showed mostly ok but 2 low and one very high. Interesting a genetic family test indicated that my body had problems processing a particular B vitamin however similar to my uncle if i had taken a broad multivitamin I could have made things worse as high intakes of one B vitamin could have hindered my body further processing the other.

Long story short take vitamins if you need them after getting blood tests. They are NOT harmless even in small quantities as they interfere with the absorption of each other. And then there are real damaging quality controls issues. There have been and are many contamination scandals not only with vitamins but pharmaceuticals - I personally have been impacted TWICE.

kerry-ann w.
18 Apr 2020

Taking vitamins can be an expensive business. The whole key is to find out what you actually need , or are deficient in , in the very first place. However most doctors do not test for the myriad of vitamins and minerals.......so I would be interested to know whether you paid for these tests privately ? The other problem is the " recommended daily dose" ........which varies drastically depending on the source of your information. Most people take a hit and miss approach, and just take a general multivitamin. The only way to know if you are benefiting from it is to stop taking it for a month and see if you notice any difference.

Martin T.
14 Apr 2020
Vitamin C

It's really easy to go online and find the first thing that debunks Vitamin C. the 2013 Cochrane study is merely an aggregation of trials. It doesn't take into account the frequency of administration which is probably the most important factor given that Vitamin C has a half-life of about 2 hours. You should consult Otago University who have done numerous studies on Vitamin C https://www.otago.ac.nz/christchurch/research/nutrition-in-medicine/outreach/otago708539.html . ( I have no connection with them )
Another variable to consider is sugar intake, as it reduces your ability to absorb vitamin C . https://en.wikipedia.org/wiki/Vitamin_C#Pharmacokinetics

It would be SO good if you dug a little deeper when researching things like this. vitamin C is probably one of the most powerful things you can take for colds & flu if you do it right.

Julian M.
16 Mar 2020

My wife and I are generally very healthy people but we seemed to be getting more than our fair share of head-colds. During a visit to my GP I raised my concerns with him and he recommended a daily dose of vitamin C. Since we've been taking it we've had far less colds and when we do them they last a much shorter time. After reading your comments perhapes it's the placebo effect but even so we won't stop taking it.

Bronwen H.
10 Mar 2020
Fortified cereals

Curious as to why you'd reccommend that fortified breakfast cereals are among the better (i.e. dietary) sources of magnesium- as opposed to supplements. Aren't those breakfast cereals fortified with the same supplements that are in the supplement jar -that aren't robustly proven to be of use?

Anny D.
15 Apr 2020
Magnesium is naturally high in cereals

Magnesium is high in cereals from rolled oats, nuts and seeds already naturally.

07 Mar 2020
Another Skeptical Individual

Sounds like a repeat of big Pharma.

So much Scientific Evidence is cash based these days so I will stick with the word of mouth from the front line.

Hamish C.
07 Mar 2020

I would hope that most NZ readers of this article would take these recommendations with a grain of salt. It is true that a good balanced diet supplies most of what the body needs and in a more natural way that the body can more easily assimilate. Unfortunately, the nutrient levels in most fruit and veges is variable at best, and even in this issue Consumer is pointing out the level of pesticides banned overseas that are still being found in our food here.
However, to state that there is no point in supplementation of certain vitamins is very misleading when there is extensive research around the benefits of Vitamin D in respiratory diseases for example, and with Vit C and other vitamins and minerals. Those who have regularly used antiviral herbal extracts for instance, know their effectiveness from personal experience, and not just the (significant) scientific evidence behind them. In my view, it is every person's right to do their own research of the evidence, to know what is right for their own immune system and body and to have the freedom to choose the direction of their own health. Blanket statements such as some of those in this article are sadly typical of the will of Big Pharma. They can't make any money when we make our own health choices.

Brendan C.
14 Apr 2020
You do realise 'Big Pharma' make loads of $$ from selling vitamins eh?

It's funny when people trot comments like this out. The supplement industry is worth hundreds of billions of dollars in sales and the 'Big Pharma' and other companies e.g Unilever, Novartis, GlaxoSmithKline make a fortune off selling supplements. They aren't in the business of selling prescription drugs they are in the business of making money.. they'd sell you anything they could turn a profit on.

Would you rather trust the word of people who want to profit from you or studies where they don't?

Ted H.
07 Mar 2020
Skeptical individual


While I agree with your recommendations about B12, calcium etc, if someone is vegan, then it seems possible to get enough omega 3 from things like flax seed, chia seed or walnuts. I have been vegan for 10 years now (since being sent home "palliative care only" with a "terminal cancer" diagnosis).

I would like to see a list of all the papers you researched in writing this story. It isn't there, and it makes me question a lot of it.

I have been taking at least 15g per day of vitamin C for 10 years now. I got rid of my "terminal cancer" tumours. I have not had any significant symptoms of any disease in that time (enough minor symptoms to know that my immune systems was busy dealing with something, but not enough for me to alter my behaviour in any way other than upping the Vit C dose to 4g per hour for a couple of days - by which time all trace of symptoms disappeared in each case).

I finished my undergrad (3rd yr) biochemistry training in 1974.

I have examined a lot of reports of studies on the effects of various regimes.
The often quoted Mayo Clinic study purporting to disprove any effect of Vitamin C on cancer is essentially a fraud. When I finally managed to track down a copy of the study in the Otago Medical School library, what they actually did was administer 2.5g at 6 hourly intervals.
Previous studies by Pauling and Cathcart had shown that there seemed to be a threshold for effectiveness that was around 5g per oral dose in most people. The Mayo study was half that threshold, though it is never reported as such, it is only ever reported as 10g per day, never 2.5g per 6 hours. So it is a true statement, that masks a bigger lie.

There is a huge amount of work being done demonstrating just how deeply our immune systems are dependent on Vitamin C. In NZ Dr Margreet Vissers is doing some great work.

Unfortunately, the current systems are much more about the needs of money than they are about the needs of ordinary individuals. There are large numbers of great people in those institutions, but the systems almost always manage to win in the end.

It seems clear to me that immune system function in most people is optimised if they take at least 6g of vitamin C at least twice a day. It has a very short half life in the body (about 20 minutes in most people) so if you suspect that your body is fighting something, then take more every hour.
If you have loose bowel motions, then reduce the dose until things firm up again. Increasing calcium (as dolomite for example) will help with that.

And at such doses, vitamin C seems to act as a chelating agent (stripping minerals from the body), so mineral supplements are a very good idea.

Anyone who wants to see what I did, and some of the key references, can check out my blog site, and the links from there:

I am not a doctor.
I trained as a biochemist a long time ago, was very good at it, and retained an interest, but spent much of my life first as a fisherman, then as a software developer.
I am not offering medical advice, just reporting what I have found in my travels.

I am very keen to see evidence.
I like to see the evidence behind recommendations.

It seems clear to me that most people would find this report deeply misleading if taken simply at face value.

Ted Howard

Brendan C.
14 Apr 2020
Still not a case for supplements...go natural

Whilst you are right about the evolving research on vitamin c and potential impact on cancer. You of all people should know correlation is not cause. People get 'miraculously cured' of a number of things and then associate it with xyz. The number of people who have used vitamin c to cure cancer is numerous, documented and most failed.

What can happen is the brakes can come off the immune system and it can clear the cancer. Studies many years ago noted patients with cancer who got infected with something that caused a large immune response often had their cancer cured. That however is just one possibility.

Anyhow you still aren't making a case for vitamins as eating the right foods can provide the vitamin c amount required. Eat a quarter of an orange twice a day for example. Your own words contradict yourself as you talk about not needing to supplement with B12 and you can get what you need from diet..but for some reason vitamin c is different??