Are supplements safe?

Health and wellness is a big business, and nutritional supplements play a big role in it. In 2019, Grandview Research estimated that the global market for health supplements was worth $123 billion.(1) And it’s likely to continue to rise.

Supplements are so ubiquitous that you’ve probably taken one at some point, or perhaps have a bottle in your bathroom cupboard at the moment. That would put you in line with the majority of Americans; a survey by the American Osteopathic Association found that 86% of American adults take some kind of supplement.(2) Some may even take more than one.

All of us are keen to improve our overall wellbeing and protect ourselves against disease. And, while we know that a healthy diet and regular exercise are the best way to do that, we often turn to supplements to ‘boost’ what we’re already doing. It’s easy to think that, if we haven’t quite been hitting our five-a-day, a vitamin supplement might help us fill in some of the gaps!

But can supplements replace the vitamins, minerals and nutrients we can source from whole foods?

What are supplements?

First, let’s define what exactly we mean by supplements.

Here, we’re talking about any product that is intended to add nutritional value to your diet or improve your health.

Some of the most common supplements are single vitamins such as vitamin C or D. However, you can also take supplements for minerals such as iron, zinc and magnesium. Some of the most popular supplements are ‘multivitamins’, which include lots of different micronutrients. They are often marketed towards specific groups such as men, women, or the elderly.

They come in all sorts of formats, from capsules and tablets to effervescent pills, jellies, drinks and more.

Supplements are designed to improve your health by either increasing your intake of specific nutrients, or addressing a deficiency in a specific nutrient. However, there is some debate about their effects on your health. Below, we’ve answered a few of the most common questions around supplements and how good they are for you.

Related reading

• Plant-based diet: Let food be thy medicine

• Seven immunity boosting foods for your diet

1. Nutrients from supplements are the same as natural ones, right?

Perhaps the most important point to make about supplements is that they are a poor substitute for real foods.

Take, for instance, vitamin C, one of the most common supplements on the market.. When we hear ‘vitamin C’, most of us think immediately of fresh fruits and vegetables, especially citrus. It’s logical to assume that’s where the vitamin C in supplements comes from.

However, most of the time that isn’t the case.

Just because a substance occurs naturally in some foods, it doesn’t mean that a supplement will contain the natural version of it. In fact, many of the vitamin C supplements on the market contain a synthetically-made version of the nutrient.

It has a similar molecular structure to natural vitamin C, but it is not the same. Rather than being naturally produced in a plant, it is made in a laboratory.

You may also come across ‘crystalline vitamins’. These are natural foods which have been treated to distill the desired vitamin, which can no longer be said to be natural. During processing, its cell structure changes, becoming crystalline. The research we cite in this piece looks into synthetic and crystalline supplements.

There is also some debate about how healthy it is to consume vitamins and minerals in an isolated state. When you eat whole foods, you absorb their vitamins, minerals, fiber, protein, fat and phytochemicals together. You also get a dose of enzymes, micronutrients and trace minerals – and those are just the ones we know about!

There’s a lot we still don’t know about how nutrients interact with one another in terms of our health. However, if you’re relying on supplements for your intake of a specific nutrient, you may be missing out on benefits from other substances.

Related reading

• How gut health is linked to the immune system

• Eat these 7 prebiotic and probiotic foods for your gut health

2. Are supplements nutritious?

Supplements work medically, rather than nutritionally. Like medicine, they are intended to treat a specific deficiency or a more general lack of nutrients. 

They are not a ‘food’, and they don’t replace food. They don’t have the macronutrients (e.g. protein, fiber and carbohydrates) of normal foodstuffs, and they don’t contain the wide range of trace micronutrients found in natural foods.

Medicines and foods both play a role in our health, but that role is very different.(3) Food is used to build up a strong, healthy body and maintain your overall wellbeing. Medicine is used to treat a specific health problem.

If you are not suffering from a confirmed health issue which requires you to increase your intake of a specific, isolated nutrient, altering your diet may be the healthier option.

For instance, if you feel you may need more iron, you could choose between eating more iron-rich foods or taking a supplement. However, eating foods such as beans, leafy greens and dried fruits will provide you with your iron plus a wealth of other healthy nutrients such as fiber, vitamins and other minerals.

3. Aren’t supplements better than nothing?

Another reason why supplements are so appealing is that they claim to take the hard work out of eating healthily. Instead of having to research which foods to eat and changing your diet, you can take a tablet and get the same effect. Right?

Sadly, there are no quick fixes for good health. Supplements are no exception!

Let’s look at a concrete example. Vitamin E is in foods such as spinach, avocado, and