Behind the popularity of food supplements there is, in particular, this idea that they can only do us good… This is to forget that there are potential dangers in multiplying the intake of vitamins and other minerals. And consumers are not always well informed.
Indeed, unlike drugs, to have their marketing authorized, food supplements are not required to provide extensive information on this point to the Australian drug regulatory body, the Therapeutic Goods Administration (TGA). (In France either, no specific marketing authorization is required, but they are monitored like any foodstuff. They are the subject of a declaration to the Department of Competition, Consumption and repression of fraud. The chemical substances used in their manufacture must also be safe, note.)
I’ve identified six ways that taking these now so common supplements could be harmful. These results were published in the specialist journal Australian Prescriber.
What are dietary supplements?
These products may contain plant extracts, vitamins, minerals, amino acids, enzymes, algae, etc. They are intended to supplement our diet, not to provide any therapeutic effect.
“Sales of complementary drugs have been boosted by Covid fears, but immune-boosting claims against them are doing more harm than good.”
In Australia, dietary supplements largely dominate the so-called complementary medicine industry, of which they are a part. Sales of dietary supplements reached 4.9 billion Australian dollars in 2017, doubling in a decade. A nationwide study in 2018 showed that 63% of people used it regularly. (Same thing in France between 2006 and 2015, as shown by the National individual studies of food consumption 2 and 3. 29% of adults and 19% of children consume it. This market weighs 2 billion euros per year, editor’s note .)
The most used food supplements are those containing vitamins and minerals: vitamin D, vitamin C, vitamin A and calcium or magnesium. According to a study published in the journal Nature, they are used by 47% of consumers.
What should you be careful about?
Many say they have never heard of the risks of dietary supplements. Which is not surprising: the communication about them mainly highlights the benefits that can be derived from their consumption. The potential risks are rarely mentioned.
The information leaflet is often limited and only rarely mentions the risks of side effects. (In France, labeling is required to provide certain information. There is also a system where observed adverse effects can be declared, nutriviligance, editor’s note.)
However, there are well-known nuisances caused by the ingredients used in the composition of food supplements. This is a well-established fact in pharmacology, especially when these ingredients are consumed in high doses.
For these reasons, in Australia, the high dose intake of certain vitamins and minerals is regulated and can only be received by a pharmacist or on medical prescription. (In France, health recommendations are also available, and indicate the maximum recommended daily doses, editor’s note.)
Received many Qs (& nasty hate mail) from supplement proposents.
Most supplements (huge industry) have little evidence to support. Often contaminated. Yes, clinically IDd need for some (eg, folic acid) & ongoing research (eg vit D).
Purpose: https://t.co/VVPqvAizH3 @DrJenGunter
—Timothy Caulfield (@CaulfieldTim) December 16, 2020
“I have received many questions (and nasty hate messages) from the promoters of the supplement. Most of them (a huge industry) have little supporting evidence. They are often contaminated. Yes, we need clinical research to identify the effectiveness of certain components (for example for folic acid and vitamin D).”
While side effects are the potential risks that come to mind first, dietary supplements can have other consequences. I have identified six of them, of different natures:
Undesirable side effects, which may arise from short-term or long-term use. Too high a dose is often the cause, but not always. Some supplements are not recommended in case of allergy, pregnancy, breastfeeding, etc.
Drug interactions: mixtures with certain treatments can lead to toxicity or reduce the effectiveness of the latter.
The cost: multiplying supplements is not insignificant.
The delay of prescription: supplements are not drugs. But it happens that taking them is considered sufficient in the face of a health problem, thus delaying the medical consultation and the implementation of an effective treatment.
Fraud and false hopes: some add-ons may display fraudulent promises.
Inappropriate mixtures: multiplying drugs and food supplements increases the risk of error: accidental overdose, unexpected side effects, etc.
Always monitor daily doses
Many supplements are taken quite safely for medical purposes. During pregnancy, women may for example be prescribed folic acid or iodine. They help to treat deficiencies in vitamins and minerals, iron, etc.
The key to safe use is the dose. The maximum doses to obtain good efficacy are known, but may not be followed in the event of self-medication… especially if the products were purchased on the internet. People who consume it can then not stick to the doses considered safe and come across unreliable indications… when they do not do what they see fit.
This is how many overlook the risk of overdose for a given nutrient, mainly vitamin B6 or vitamin A, which can occur if you multiply the supplements.
When trying to assess the potential benefit or risk of a dietary supplement, it is important not to be limited to its best-known or main ingredient: it is necessary to determine what all its compounds are, at what dose they are present in order to to avoid overdoses if you take other supplements where they are also present. Health professionals can assist everyone, explain why it is important to respect this or that dosage for reasons of risk and optimal effectiveness. (In France, pharmacists and doctors are able to indicate whether taking supplements is not recommended due to the person’s state of health, for example in the event of renal or hepatic insufficiency or even a risk of drug interaction, editor’s note)
It is sometimes necessary to go further than the only information indicated by the manufacturers, who should make their information more accessible. As widespread as they are now, food supplements are not trivial.
This article is republished from The Conversation under a Creative Commons license. Read the original article.