Supplements We Always Get Asked About...

November 03 2026, 6 min reading time

Supplements can support your health when there is a genuine need, but choosing the right product, form and dose is important. This guide explores five commonly used supplements - iron, magnesium, vitamin D, glucosamine sulfate and B-complex vitamins - including what to look for and how to take them.

Supplements can be useful when there is a genuine deficiency, increased requirement or evidence-based health goal. If you’re considering supplementation or have been recommended a specific supplement by your GP, speak with your DCO Pharmacist to ensure you're choosing the right product and dose for your individual needs.

1. Iron: Healthy Blood and Energy

Iron is essential for making haemoglobin, the protein that carries oxygen around the body. Low iron levels can cause fatigue, poor concentration, shortness of breath and reduced exercise performance.

What to look for:
Look for the amount of elemental iron, not just the total compound weight. Iron bisglycinate is generally gentler on the stomach, while ferrous sulfate remains the standard treatment option for iron deficiency. Ferrous forms are typically better absorbed than ferric forms.

Popular brands:

Ferro-Grad C
Maltofer
Blackmores Bio Iron Advanced
Quality Health High Absorption Iron+

Best way to take it:
Take on an empty stomach if tolerated, ideally with vitamin C. Avoid taking iron with tea, coffee, calcium or dairy products as they can reduce absorption.

2. Magnesium: Muscles and Recovery

Magnesium supports muscle function, nerve signalling and energy production. It is commonly used for muscle cramps, tight muscles and recovery after exercise.

What to look for:
Magnesium glycinate and citrate are generally better absorbed than magnesium oxide. Glycinate is often preferred when sleep or muscle relaxation is a goal.

Popular brands:

Ethical Nutrients Mega Magnesium
Nutra-Life Magnesium Hi-Zorb
Blackmores Bio Magnesium
Swisse Ultiboost Magnesium

Best way to take it:
Many people prefer taking magnesium in the evening as it may promote muscle relaxation. Take with food if it causes stomach upset.

3. Vitamin D: Immunity and Bone Health

Despite Australia's sunny climate, vitamin D deficiency remains common, particularly in people who spend most of their time indoors, have darker skin or use extensive sun protection. Vitamin D supports immune function, bone health and muscle strength.

What to look for:
Choose Vitamin D3 (cholecalciferol), the form naturally produced by the skin. Common strengths range from 1,000 IU (25 micrograms) to higher-dose preparations prescribed by healthcare professionals.

Popular brands:

APO Vitamin D
Ostelin Vitamin D
Blackmores Vitamin D3
Nature's Own Vitamin D3

Best way to take it:
Take with a meal containing some fat to improve absorption. Morning is often recommended.³

4. Glucosamine Sulfate: Joint Health

Glucosamine sulfate is commonly used by people with mild to moderate osteoarthritis, particularly of the knee. It can help provide the building block for cartilage and may help reduce joint discomfort in some people over time.

What to look for:
The evidence supports glucosamine sulfate, not glucosamine hydrochloride. Look for products providing around 1,500 mg daily.

Popular brands:

Blackmores Glucosamine Sulfate 1500
Nature's Own Glucosamine Sulfate
Healthy Care Glucosamine

Best way to take it:
Take with food. Benefits may take 4–8 weeks to become noticeable.

5. B-Complex Vitamins: Energy Production

B vitamins help convert food into energy and support the nervous system. The B vitamins work together to support metabolism, red blood cell production and nervous system health.

What to look for:
A balanced B-complex should contain B1, B2, B3, B5, B6, folate and B12. Avoid unnecessarily high doses of vitamin B6 unless advised by a healthcare professional.

Popular brands: