The market for food supplements is booming. A 2018 report for the UK Food Standards Agency suggesting that by 2021 it will be a £1 billion market.1 The same report noted that many people were taking daily supplements with a ‘better safe than sorry’ attitude, hoping to support health and believing there to be no real danger in regularly taking supplements purchased from a high street health food chain.1

In my opinion there are three key points to make clear about supplements:

1. Supplements are not always safe
2. Supplements are often not as effective as food
3. High quality supplements can be a useful short-term strategy to optimize health

1. Supplements are not always safe

There are circumstances in which certain supplements can do more harm than good. For instance, many supplements interact with medication – either increasing or reducing its affects.2 Many supplements can cause toxicity at high doses – e.g. iron.3 There are also supplements that might be useful for short-term use, but potentially damaging for long-term use. There are supplements for which research on long-term use does not yet exist. A qualified Nutritional Therapist, Nutritionist or Dietician will be trained in understanding and researching which supplements might be useful and which are to be avoided for each individual client.

2. Supplements are often not as effective as food.

This is largely due to the fact that nutrients do not work in isolation. All processes in the body require a combination of nutrients, and many of these nutrients even require others in order to be absorbed into the blood stream. For instance, vitamins A, D, E and K are ‘fat-soluble’ – to absorb them, you need fat.4 Another example is that calcium needs vitamin D in order to get into bones and teeth where it is a vital nutrient.5 Simply popping a pill with one of these nutrients isn’t actually going to help the body – in many cases, supplements purchased from high street brands will simply pass straight through you! In contrast, many food sources of vitamins A, D, E and K already contain fats, and many sources of calcium already contain vitamin D. Higher quality supplement brands are more carefully formulated to include nutrients that enhance each other’s bioavailability – the ability to be absorbed and utilised by the body. A qualified professional can help source and recommend these if appropriate.

3. Supplements carefully selected and tailored to an individual’s needs can be a useful short-term strategy to optimise health

I do use supplements in clinic in short-term, ‘therapeutic’ doses. A carefully selected dose of certain nutrients can help the body to re-establish it’s optimal state – be that in terms of hormonal balance, digestive function or any other system function. The idea of this is to then add more foods into the diet that contains those nutrients, so that an individual can obtain everything required for healthy body function from diet alone. In some cases this might be impossible and a supplement might be required long-term, for instance in certain conditions or if someone is following a vegan diet, but this should always be monitored by a qualified Nutritionist or in some cases by a GP.


1. (2018). Food Supplements Consumer Research: Final Report for Food Standards Agency. [online] Available at: [Accessed 30 Jul. 2019].
2. NCCIH. (2019). Know the Science: How Medications and Supplements Can Interact. [online] Available at: [Accessed 30 Jul. 2019].
3. Abbaspour, N., Hurrell, R., & Kelishadi, R. (2014). Review on iron and its importance for human health. Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences, 19(2), 164–174.
4. British Nutrition Foundation. (2019). Vitamins – British Nutrition Foundation. [online] Available at: [Accessed 30 Jul. 2019].
5. Wimalawansa, S., Razzaque, M. and Al-Daghri, N. (2018). Calcium and vitamin D in human health: Hype or real?. The Journal of Steroid Biochemistry and Molecular Biology, 180, pp.4-14.