Supplements 101: What you need to know

From algae to zinc, this is everything you need to know about supplements and how to choose


Supplements are a big deal these days. In the USA, 80% of people take some form of nutritional supplement, while the NHS recommends that everyone take a vitamin D supplement in the winter.

But if you aren’t a nutritional biochemist or a dietitian, it can be difficult to know what’s really going on. Which nutrients are essential, and which have no real impact? Are all supplements the same, or is there a difference between high-quality supplements and the cheap ones at the pharmacy? And how do you know what to actually expect? In this article, we’ll be taking a deeper look at what supplements are, what benefits they have, and whether you should take a supplement.

What is a supplement?

Let’s start with the big questions. Supplement is a wide-ranging term—any food product taken with the aim of adding a particular nutrient could be considered a ‘supplement’. However, in general, when we talk about supplements, we’re talking about pills or tablets that include any combination of vitamins, minerals, herbal extracts, antioxidants, fatty acids—you get the picture.

Why take a supplement?

Micronutrients, such as vitamins and minerals, are essential for a huge number of fundamental processes within the body and the brain, from metabolism and energy production to immune and psychological function.

But the problem is, with the exception of vitamin D, we can’t manufacture vitamins ourselves, so we need to get them from our diet. Historically we’ve eaten a broad enough diet to get these essential nutrients and thrive. Or alternatively, to be completely honest, we’ve just not been very healthy—medieval diets of pottage and porridge coincide with life expectancies of around 35. Times have changed.

These days, as a society, we’re healthier, but the proliferation of ultra-processed food, combined with more expensive fresh produce, and less time to cook healthily means that a lot of us (up to 99%) aren’t getting the nutrients we need from our diet alone. And even if we ate a perfect diet, it wouldn’t necessarily be enough—soil degradation caused by intensive farming lowers the nutrient value of the earth that crops are grown in. That means fewer nutrients for us.

So instead of letting their nutrient intake plummet, many people are turning to supplements to provide a boost to their diets.

What are the benefits of taking a supplement?

Put bluntly, they can help people stay healthy. No food product should be considered to have a medicinal quality—they can’t cure or prevent disease—but they can contribute to healthy, normal functioning of just about every physiological process in your body.

Some examples of nutrients and the processes they help include:

  • Omega 3 EPA contributes to normal heart health.

  • Omega 3 DHA is essential for brain function.

  • Folate (B9), iron, and vitamins A, C, D, B6 and B12 support immune function.

  • Vitamin D is essential in the maintenance of strong, healthy bones and teeth.

  • Zinc and biotin (B7) maintain hair and skin.

  • Thiamin (B1) and riboflavin (B2) play a role in nerve function and vitamin D maintains muscle function.

  • Vitamin B12 and iron support energy metabolism and regulate tiredness.

  • Vitamin C and the full B complex support normal psychological function.

  • Vitamin B5 supports mental performance.

  • Selenium, zinc, and vitamins B2, C, and E contribute to the protection of cells against oxidative stress.

That’s a long list already, but it could go on much further. Find out more here .

Does it matter which supplement I take

In a word, yes.

High-quality, science-backed supplements, taken daily, can be helpful in maintaining healthy levels of essential vitamins and minerals. Unfortunately, not all supplements are created equal.

How to spot a quality supplement

Choosing a supplement can be overwhelming—there are literally thousands of brands to choose from. These are the questions to ask.

1. Which nutrients does it contain?

First things first—what is in there? Does it have a well-rounded range of nutrients? Are they all in impactful amounts, or is there just enough to be able to list it on the label?

Some nutrients, like omega 3, are often missed out by cheap multivitamins because they come in liquid form. Without a double-barrier capsule, that can interfere with the other nutrients.

Fat-soluble vitamins must be taken with an oil of one sort or another. All of these things, and more, are worth considering.

2. What are the specific compounds they use?

Nutrients come in many different forms, and most people don’t know the difference. That’s understandable—you aren’t expected to know the difference between cyanocobalamin and methylcobalamin (two common forms of vitamin B12).

But these forms matter. They interact differently with our body’s digestive system and biochemistry, so some are much easier to absorb, and therefore receive the benefits from, than others. This is called bioavailability , and in general, you always want to ensure you’re getting a bioavailable form of the nutrient. Otherwise, you’re just wasting money.

3. What else is in there?

Too many multivitamins and other supplements contain more than you bargained for. Whether that’s added sugar, synthetic colourings or flavourings, fillers, caking agents, or even leftovers from the industrial process, it’s something to be aware of. For example, titanium dioxide was ruled unfit for human consumption in 2021, but some unscrupulous companies still include it (it’s a cheap way to make your pill a bright white colour).

4. Is it backed by science?

Nutrition is a complex area of health, and while there is lots of excellent research out there, there’s also a lot of pseudoscientific nonsense. Ensure that any supplement you take is made by a company committed to scientific rigour. Ideally, they’ll invest in independent research and evidence-based development, which should give you some peace of mind that it will actually work.

Want to know more? We spoke to Heights Head of Nutritional Research and acclaimed dietitian Sophie Medlin here .

Who should take a supplement?

The vast majority of people don’t get the recommended doses (known as NRVs ) of vitamins and minerals from their diet. In this situation, they might want to take a supplement to help them fill in the nutrient gaps, and ensure they’re getting what they need to function properly.

On top of that, some supplements are recommended for everyone—for example, the NHS recommends that everyone in the UK take a high-quality supplement that includes vitamin D in the winter months.

Make sure that, if you have specific nutritional or health needs, you consult a doctor before starting a new supplement. That way you can be confident that it’s the right fit for you.

Why do people take supplements?

Different people have different motivations for taking a supplement, and ultimately, it’s a personal decision related to your health. However, some reasons that people take a high-quality supplement include:

  • Providing a nutritional safety net, so you don’t worry about where your nutrients are coming from

  • Maintaining a healthy body, from your toenails to your hair.

  • Doing the best thing for your future health

  • Supporting your natural sleep patterns

  • Feeling more energy in your day-to-day life

  • Clearing your head to help you focus better

  • A healthcare professional might suggest you take a supplement for a specific area of your health

With all that in mind, you can see that for lots of people, a supplement can be beneficial. And while people with specific health needs should talk to a doctor before starting anything new, a high-quality, science-backed supplement offering a comprehensive combination of vitamins, minerals, antioxidants and fatty acids can help support healthy people in their everyday lives.

So now you know a bit more about supplements, here are some of the most important things to watch out for when choosing one. Some of the common industry practices are shocking, so make sure you avoid the worst offenders. Find out more here .


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