What Is A Dietary Supplement?

Jessica Clifton

by Jessica Clifton

5th August 2020

What is a dietary supplement? Well, dietary supplements can be minerals, vitamins, proteins, enzymes, or any other nutritional products that are marketed as health-boosting food supplements. 

Sometimes, dietary supplements are even implied to have natural curative or holistic properties. However, this belief is often contradicted by the disclaimers on the products’ labels, which assert that they do not have any approved medicinal properties.

Dietary supplements come in a variety of forms and packages:

  • Some are taken as pills and tablets, like vitamin supplements
  • Others are found as a powder that can be dissolved in water
  • Dietary supplements can even come in the form of energy drinks
Diet supplements in powder and pill forms

Diet supplements can come in powder and pill forms

Many supplements are sold as our favourite beverages that have been fortified with certain nutrients and antioxidants. This includes things like coffee, tea, and chocolate drinks. Other dietary supplements are marketed as protein shakes, while some are sold as ingredients that can be added to cooked food.

Virtually all dietary supplements claim to include natural ingredients, ranging from nutrient minerals to exotic extracts derived from fungi, herbs or even plankton. Many of these ingredients are famed for having cleansing or detoxifying properties, while others are heralded for their effectiveness as beauty and rejuvenation products. While there is some truth to these rumours, in that dietary supplements have been known to improve health and manage some health conditions, not all claims about these products are empirically supported.

What Does a Dietary Supplement Do?

Depending on the type of product, as well as the company that manufactures it, there are several claims about what dietary supplements do. It is a common misconception that, due to their typical capsule form and list of ingredients, dietary supplements are used for medicinal purposed. However, while they may resemble medicines, dietary supplements are not meant to cure or treat illnesses. 

Generally speaking, manufacturers and distributors of these products have three main claims:

  • “Dietary supplements maintain good health”

It’s true that not everybody needs dietary supplements to maintain good health, because virtually all of the essential nutrients our bodies need can be derived from common foods. 

However, there are many reasons why a person’s health would benefit from supplements. For example, those with a weaker immune system may need certain supplements to stay healthy, just as an athlete would need them to replenish their loss of electrolytes after exercising.

  • “Dietary supplements can improve health” 

If you’re nutrient-deficient, dietary supplements might be very useful. This is because some vitamins are not readily available in food. For someone to produce enough vitamin D, for instance, they must have sufficient sunlight exposure. Vitamin D supplements can therefore be used to improve this deficiency.

While a lot of dietary supplements are marketed as arbitrary weight loss products, they are required by many people who are unable to get certain nutrients due to lifestyle, circumstance, or dietary requirements. 

Man who has lost a lot of weight holding some dietary supplements

Many dietary supplements are marketed as weight loss products

  • “Dietary supplements help manage some medical conditions”

Medical conditions as a result of ageing mean that many elderly people have to use dietary supplements in order to manage their ailments. For example, taking calcium supplements can help prevent osteoporosis, as well as the weakening of the bones that happens with age.

There are many more medical conditions that supplements can help manage. For at-risk individuals, taking omega-3 can lower chances of heart disease. Meanwhile, those who are pre-diabetic, or already diabetic, can manage their blood sugar levels with the help of dietary supplements like cinnamon extracts, berberine, alpha-lipoic acid, and magnesium.

What’s the Difference Between a Food Supplement and a Dietary Supplement?

Food supplements and dietary supplements are synonymous, and usually interchangeable terms. Either one can refer to the same thing. However, there are some distinctions depending on the regulations and how companies brand these products.

The main difference between food and dietary supplements is the packaging, rather than the product itself. Dietary supplements are generally sold as tablets or capsules. Meanwhile, food supplements can appear in any form, from powders and liquids to fortified food ingredients.

Another distinction lies in the fact that some dietary supplements may be recommended to you by your  doctor. This is usually if you are not consuming nutrients in high-enough quantities and are starting to suffer health issues. Food supplements, on the other hand, are usually self-prescribed, and are sometimes easier to incorporate into a diet due to the more accessible forms they come in. 

Are Dietary Supplements Safe?

While dietary supplements are generally considered safe to use, it all depends on what it is you’re consuming. For example, fat-soluble vitamins, including A, D and E, can cause some negative health effects if you take too many – so remember that too much of a good thing can also have its consequences.  

To ensure safety when taking dietary supplements, and to avoid any adverse side-effects, always consult your doctor before taking any. Another risk to keep in mind is that dietary supplements also have some contraindications with regular medications, or with certain health conditions:

  • Taking vitamin K supplements inhibits the efficacy of the blood thinner medication, warfarin. This means that if you are taking a blood thinner medication for hypertension, for example, you will increase your risk of having a stroke if you take vitamin K supplements. This is because vitamin K has a significant role in blood coagulation.
  • Supplements like vitamin C and E are antioxidants that help the body fight against infection. While these supplements may seem harmless, they are potentially harmful for people who have cancer because they may interfere with the effectiveness of chemotherapy. 

Aside from consulting your doctor, you should also read the labels of dietary supplements before taking them. If the labels do not contain sufficient information, you could visit the manufacturer’s website, or other websites that provide the information you need. Do your research to see if there are any ingredients that are potentially harmful to you. This is also important in making sure you’re not allergic to any of the ingredients.

Overdosing on supplements could also damage your organs, particularly your kidneys and liver. Special caution should be taken when considering diet pills and fat burners, as they are particularly easy to overdose on. Finally, always make sure that the product you intend to take has been approved by the UK’s Medicines & Healthcare Products Regulatory Agency (or any other equivalent bodies if you live outside of the UK).

Should I Take a Dietary Supplement?

If you are healthy and have sufficient nutrition from the food you eat, you probably don’t need to take dietary supplements. However, there are some situations where you may need to take specific supplements if recommended by your doctor. A few examples are:

  • If you have specific nutritional deficiency, such as vitamin D deficiency
  • If you have a health condition, like diabetes, that requires dietary supplements
  • If you are pregnant, you may need iron and calcium supplements
  • If you are an athlete, you may need protein and mineral supplements
  • If you are an elderly person, you may need supplements to help to boost your immune system

Knowing the benefits and risks of a dietary supplement will help you to make informed decisions about your diet. Just like medicines, these supplements should not be abused, so make sure you do your research and consult a doctor beforehand.


All content published on the ReAgent.ie blog is for information only. The blog, its authors, and affiliates cannot be held responsible for any accident, injury or damage caused in part or directly from using the information provided. Additionally, we do not recommend using any chemical without reading the Material Safety Data Sheet (MSDS), which can be obtained from the manufacturer. You should also follow any safety advice and precautions listed on the product label. If you have health and safety related questions, visit HSE.gov.uk.