More isn’t always better – top tips on how to know what your body actually needs

My husband works in the sports industry and this morning he asked me to look at a product to work out its value and potential efficacy. It’s something I get asked a lot in clinic too. Supplements can be amazing and used at the right time, for the right duration can be potent in getting us to optimal health, healing and recovery.

But it is a supplement minefield out there.

Walk into any health shop or even supermarket and you’ll find shelves lined with supplements full of promises. Better energy, better sleep, better skin, better hormones – the list goes on. Vitamins, probiotics, prebiotics, electrolytes, liver detox, hormone balance, skin support. How do we make sense of it all?

There are a few things that don’t quite make it onto the label – or into the glossy marketing. And there are more questions – what if taking more isn’t the answer? Perhaps more importantly, what if taking the wrong thing, for too long, is working against us?

So what do we actually need to know to make good decisions? From the many conversations I’ve had in clinic over the years, below are the core foundations and key principles I come back to – a few simple things to consider when deciding which supplements to take.

In the UK, supplements are regulated as foods rather than medicines. That means they don’t have to prove clinical effectiveness before they reach the shelf. Ingredients and doses should be listed, but the quality, the form of the nutrient, and how well it can actually be absorbed can vary enormously. Two products can look almost identical on the label but behave very differently in the body.

Our stomach is not just a holding bay. It is a powerful defence barrier. Its job is to break things down, neutralise potential threats, and create the conditions in our food to help determine what can be absorbed further down the line.

Some supplements don’t survive that journey intact. Others are altered along the way. And some never get absorbed in any meaningful amount at all. For a supplement to work, it has to survive digestion, be released from its capsule or tablet, pass through the gut wall and then actually be usable by the body. This is what we mean by supplements or foods being bioavailable – how much of what you take or eat can actually be absorbed and/or made use of.

Crucially, before adding something in, it’s often worth asking what might need taking out. Is the ongoing stress, ultra-processed food, or simply the pace we’re living at creating your symptoms. All of these place a load on the body, affecting how well we digest, absorb nutrients, and clear what we no longer need. This extra load frequently leads to the issues we are trying to treat with supplements.

Rather than getting lost in the detail, here are my three top tips when choosing a supplement:

  • Which supplement do you need—and why?
    What are you trying to address? Fatigue, constipation, skin issues, poor sleep, hormonal problems? Then gently keep asking ‘Why?’ For example Fatigue; why am I tired? low iron, poor sleep, blood sugar swings, stress, or simply not eating enough protein. Keep going until the answer feels like it lands somewhere real – even if it’s not the most convenient answer.Where possible, it can be helpful to have a clearer understanding of what’s going on under the surface. In some cases, this might mean simple testing – blood tests for iron, B12 or vitamin D, or occasionally stool testing for a more exhaustive list of markers. This doesn’t need to be overcomplicated, but having a clearer picture can help guide more targeted and effective support.Some supplements are best used when there is a known or strongly suspected deficiency, rather than taken “just in case.” It doesn’t mean we need to test everything, but it does mean being thoughtful about what we’re adding in. Supplements can support a system, but they rarely fix the root cause on their own—so understanding the ‘why’ is always the most valuable place to start.
  • What’s actually in it?
    Always turn the packet over. Beyond the headline ingredient, many supplements contain binders, fillers, stabilisers, sweeteners and coatings. They make supplements easier to produce and last longer, but they don’t always sit passively in the body. Some can affect how well a nutrient is released and absorbed, others can irritate the gut or simply add to the body’s processing load. This is of particular importance when multiple supplements are taken daily. A good rule of thumb is that if the ingredient list looks complicated, pause. Simpler is usually better: fewer ingredients, words you recognise, clearly labelled doses, and forms the body can use.
  • How long should you take it for?
    This is where balance is key. For some people taking supplements daily is a nuisance, while others stay on the same ones for years. In reality, supplements are best thought of as tools rather than habits. They can help correct a deficiency or support the body during a period of stress, but they are not always designed to be taken indefinitely. The body is adaptive – if we continually supply something externally, it can begin to adjust its own internal regulation. So it’s worth checking in from time to time: do I still need this? And if I needed it in the first place, what else might help address that underlying cause?

I like to think of supplements as a nudge – supporting the body at the right time, for the right reason. Problems can arise when that nudge becomes a constant push.

Things I see in clinic

Magnesium:

One patient comes to mind who arrived saying she felt completely exhausted- at the same time, couldn’t switch off. She described herself as “wired but tired.” Sleep was broken, her shoulders and neck were constantly tight, and headaches had become a regular part of her week.

Nothing dramatic showed up in her history, but her nervous system was clearly under strain – too much going on for too long, without enough opportunity to properly come down.

We made some simple changes around her evening routine and breathing, and alongside that introduced a gentle magnesium supplement in the evenings.

Over the next few weeks, things began to shift. Sleep became deeper and more settled, the constant muscle tension eased, and the headaches became far less frequent. She didn’t feel “knocked out” or sedated – just calmer, more able to switch off. This enabled her to re-charge and restore in her down time, resulting in her feeling more like herself again.

In this case, the magnesium wasn’t forcing anything or overriding the system – it was simply giving the body a bit of what it needed to do its job more effectively.

As a side note – not everyone tolerates oral magnesium particularly well – it can sometimes upset the gut or cause loose stools. In those cases, alternatives such as Epsom salt baths can still be helpful. While we don’t fully rely on absorption through the skin, the combination of warmth, relaxation and the magnesium salts themselves can support the body in a similar way, helping muscles soften and the nervous system begin to settle.

Vitamin D

Another patient comes to mind who had been taking high-dose vitamin D for quite some time. Like many people, she had started during Covid, when there was a strong push around immune support, and had simply continued – partly out of habit, and partly because it felt like a sensible thing to do.

Over time, she began to feel a little “off.” Nothing dramatic, but a general sense of fatigue, some digestive discomfort, and a feeling that things just weren’t quite right. She was doing all the right things otherwise – eating well, moving regularly – so it didn’t immediately make sense.

When something doesn’t quite add up, it’s often worth stepping back and checking the basics. In this case, we arranged a simple blood test to look at her vitamin D levels, along with calcium.

Her vitamin D came back higher than we would ideally like to see, and her calcium was sitting towards the upper end of normal. Not dangerous, but enough to suggest that the balance was starting to shift.

We paused the supplement, made a few gentle adjustments to her diet and hydration, and allowed things to settle.

Over the following weeks, her energy began to improve, her digestion felt more comfortable, and that vague sense of “not quite right” lifted.

This is not to say vitamin D isn’t important – it absolutely is, and many people do benefit from supplementation, particularly in the UK. But it’s a good example of how something helpful in one context can become unhelpful when taken longer than needed, or at a dose that no longer matches what the body requires.

A simple blood test—looking at serum 25-hydroxyvitamin D, and ideally calcium alongside it—can give a clear picture of where you are, and help guide whether supplementation is needed, and at what dose.

Sometimes it’s not about adding more in, but about knowing when to pause.

Vit C

A different example, and one I see work very well in practice, is Vitamin C. When someone feels that first shift—slightly run down, a scratchy throat, that sense that something is brewing—a short course of higher-dose vitamin C can be incredibly supportive. Vitamin C plays a key role in immune function, supporting white blood cell activity and acting as an antioxidant during times of increased stress on the body. There is good evidence that while it may not prevent illness in the general population, it can reduce the duration and severity of symptoms, particularly when taken at the onset.

Used in this way – short term, responsive, and alongside rest and nourishment – it can help the body do what it is already trying to do, rather than overriding it. And importantly, once the system has settled, it’s something that can then be stepped away from again.

It’s less about taking something every day “just in case,” and more about knowing when to step in and support the body when it needs it most. Ideally, most of what we need comes from food – whole, minimally processed, seasonal where possible, and as close to how nature intended. The body tends to recognise and handle this far more easily than isolated nutrients in a capsule.

Your body is beautifully intelligent – but it wasn’t designed to process a chemistry set.

The closer we stay to what it recognises, the better it tends to respond.