Ask a Dietitian: Do I Really Need to Use Supplements?

The use of supplements has become so common in recent years. There are so many different types and different brands available now, and it can be hard to decide the right supplements to buy, and whether we even really need them.

First things first, you don’t need to take supplements to be healthy. If you are eating an adequate and varied diet full of fruit, vegetables, whole grains, nuts and seeds, healthy fats and protein foods, this should provide your body with the nutrients it needs to thrive. There are times however where supplementing might be useful, depending on your age, activity levels, stress levels, allergies, intolerances, or dietary intake. 

When choosing a supplement, it is important to understand what you are buying to ensure it doesn't contain harmful ingredients, that it's actually useful, and to prevent wasting money on something that may not even work.

Here is a breakdown of some of the most common supplements, including what each is, how to use it, and the benefits of sustained use. 

Protein powders

What is it?

There are various types of protein powders available including whey protein isolate, whey protein concentrate, and casein protein. Whey protein isolate (WPI) is the isolated whey made as a by-product of cheese, usually with minimal other ingredients added, and is often the most suitable protein powder for the average active adult.


Protein powder can be used as a protein top-up and is a convenient option when you are on-the-go. It is also a convenient option for people with very high energy needs such as athletes. People often use protein powder after exercise to assist recovery. Food sources of protein are usually more beneficial than a powder as they will provide nutrients beyond protein, such as fibre, vitamins, or other minerals.

What to look for:

There can be a lot of variability in quality between brands so if choosing to use a protein powder look for an Australian brand as the quality is often much better than those made overseas.


What is it?

Multivitamins contain a mixture of vitamins and minerals, with brands differing in the amounts and types of vitamins in their supplements. Typically containing a mix of B vitamins, vitamin C, A, E, and minerals such as calcium and magnesium, multivitamins aren’t necessary for all situations as these nutrients can be sourced from the diet.


A multivitamin can be useful if you aren’t eating enough of certain food groups to meet nutrient requirements. Think of multivitamins as a top-up, but not a substitute for healthy eating. It can also be useful to take a multivitamin during periods of stress, illness, or increased physical activity to replenish nutrients and keep your body healthy.  

What to look for:

There can be a lot of variability between multivitamin supplements. A product that has a long list of ingredients may only provide a small amount of each vitamin and mineral that won’t be very useful, whereas a multivitamin with fewer ingredients may be more likely to provide vitamins and minerals in the recommended daily amounts so would be more beneficial to support health. A GP or Dietitian can assist you in deciding on the right product to suit your needs.  

Fish Oil

What is it?

Fish oil is rich in the omega-3 fatty acids EPA and DHA that support overall health. The body doesn’t produce omega-3 so it must be consumed through the diet, with the best sources including oily fish such as salmon, trout, sardines, mackerel, and tuna.


Omega-3 fatty acids have been found to support cardiovascular health, brain health, cognitive health, helps to reduce inflammation and can support our mental wellbeing. The body can convert plant-based fats (ALA) into EPA and DHA, but only in very small amounts. Larger amounts are thought to be needed for overall health, so if you aren’t consuming fish such as salmon, trout, mackerel or tuna regularly, then supplementation may be helpful.

What to look for:

If choosing to supplement, choose a fish oil that will provide the recommended intake of EPA and DHA. The Australian NHMRC suggests a daily intake of at least 610mg for adult men and 430mg for adult women. Make sure to seek advice if you have existing heart conditions or are on medications for heart or blood thinning.


What is it?

Probiotics are live bacteria that can have health benefits for your gut microbiome. There are hundreds of species of bacteria living in the gut that each have unique characteristics and benefits in the body. Gut health is believed to be associated with overall health, wellbeing and risk of certain diseases.


Consuming probiotics may help to improve digestion and absorption of nutrients, and increase the diversity of bacteria living in your gut (linked with improved health). There are different strains of probiotics that can have different benefits in the body. For example, some probiotics are beneficial to restore bacteria after a course of antibiotics or illness, whereas other strains of probiotics may improve symptoms in people with irritable bowel syndrome. 

What to look for:

Look for a probiotic strain that will benefit the area you are looking to improve. It is best to seek advice from your GP or Dietitian for advice on the best options. 


What is it?

Magnesium is a mineral that is found in our food and is needed for hundreds of biochemical reactions in the body, helping to maintain nerve and muscle function as well as support our immune system. Magnesium supplements come in many forms, including powdered and capsule magnesium. It is also common to see magnesium body scrubs and sprays.


There are many claims about magnesium supplements and their use, such as improving sleep and cramping, reductions in blood pressure, improved insulin sensitivity, improved bone mineral density and more. Most of these claims are not backed up by the evidence in research or more research is needed to support recommendations. Magnesium supplements may be useful before bed as studies have seen improvements in sleep in those with poor sleep quality.

What to look for:

Discuss with your GP and Dietitian if you are taking any other medications. Excess magnesium can result in gastrointestinal symptoms.

If you are thinking about supplements, make sure to touch base with your GP and Dietitian before use as some supplements can be harmful when used incorrectly or in excess. 

Explore more content like this in our series, Ask a Dietitian

Health & Performance Collective is the brainchild of Sydney Dietitians Jessica Spendlove and Chloe McLeod. They use their 20 years of combined knowledge and skills as dietitians to work with motivated people to live and perform at their best.

Enjoyed this? Here are 7 foods that help you sleep.

Rust Stripe 100% Flax Linen Fitted Sheet

You're eligible for a free candle!

We'd love to send you one of our hand-poured, 55-hours Australian-made candles with your order. Select your preferred scent below, and leave the rest to us.
No Thank You
Your Order 0
(incl. GST) 20.00
or 4 interest-free installments as low as by

Take 10% Off Your Order

Plus, earn 10 bonus Sister Club points per $1 spent.

Together with Priceline, we invite you to indulge in the space and sleep of your dreams.

Enter your Sister Club Membership below to unlock your exclusive discount.

Australian customers only. See our terms. Your discount will be automatically applied at Checkout.

Thanks - You're In!

Shop Now