Not All Supplements Are Created Equal
Practitioner-Only vs Retail Supplements
As a Clinical Nutritionist, one question I am often asked is: "Can I just buy my supplements from the supermarket or off the shelf at the chemist?" Here are the reasons why I do not generally recommend this as the best choice.
Quality and Therapeutic Dosing
Practitioner-only supplements typically contain therapeutic doses. These are the amounts shown in clinical research to actually treat conditions, not just prevent deficiency. A supermarket magnesium might contain 100mg of elemental magnesium, while a practitioner formula may provide 300-400mg in highly bioavailable forms. The difference matters when you are trying to address conditions or symptoms such as sleep issues, muscle cramps, or anxiety, rather than simply ticking a nutritional box.
Quality control is another dividing line. Practitioner-only brands generally use third-party testing, pharmaceutical-grade ingredients, and rigorous batch testing. This means that what is listed on the label is actually in the bottle, at the stated potency. They are also more likely to be free from unnecessary fillers, allergens, and contaminants that can compromise both efficacy and safety.
Retail products, while regulated, often contain lower doses that may be insufficient to achieve a therapeutic benefit. They may also use cheaper, less bioavailable forms of nutrients to keep costs down, meaning you absorb less of what you are actually paying for. This means that when it comes to nutritional supplements, you really do get what you pay for.
The Right Form Matters
Perhaps most importantly, not all forms of nutrients are created equal. Magnesium alone comes in many different forms. Magnesium bisglycinate is often prescribed to support sleep quality and the nervous system, magnesium orotate may be prescribed to support cardiovascular health, higher doses of magnesium citrate can be prescribed for constipation, and magnesium threonate may be prescribed for cognitive function. Prescribing magnesium oxide (common in many retail products, and poorly absorbed) for someone with migraines when they really need magnesium glycinate means they're unlikely to experience the relief they need.
The same principle applies across other nutrients: methylated B vitamins will better support those with MTHFR genetic variations, chelated minerals are used for enhanced absorption, and specific amino acid forms can target particular metabolic pathways. One of the most commonly prescribed supplements is iron. Iron bisglycinate is likely to cause far less digestive upset than the ferrous sulphate form. When it comes to zinc supplementation, the body absorbs zinc picolinate more effectively than zinc oxide. I could go on.
These distinctions determine whether a supplement actually works. So without understanding which form addresses which concern, you are more likely taking a shot in the dark, and potentially wasting money on products that your body either does not need, or cannot properly utilise.
The Hidden Dangers of Self-Prescribing
Self-prescribing carries real risks that many people either do not know about, or consider. Many supplements interact with medications. For example, inositol and diabetes medications, vitamin K with warfarin, and high-dose vitamin E with blood thinners. Without properly checking for interactions between medications and supplements, you could be undermining your treatment, or worse, putting yourself at risk for serious adverse effects.
The B6 Toxicity Problem
A topic of recent concern has been vitamin B6 toxicity from inadvertent over-supplementation. B6 (pyridoxine) appears in many supplements, from multivitamins, B-complex formulas, stress formulas, energy supplements, pre-workout powders, and even some protein shakes. A client might take a multivitamin with 25mg of B6, a B-complex with another 35mg, and a stress formula with 30mg. Suddenly they are using 90mg daily when the upper limit is set at 50mg for adults. Chronic excessive B6 intake can cause peripheral neuropathy. This is numbness, tingling, and pain in the hands and feet that may be irreversible, even after stopping supplementation.
Other Doubling-Up Dangers
The same problem occurs with other nutrients. Excess vitamin A can cause headaches, blurred vision, liver damage and can be teratogenic in pregnancy (adversely affecting foetal development). Too much selenium may lead to hair loss, brittle nails, and neurological symptoms. Over-supplementing iron when you do not need it can create oxidative stress and increase infection risk, as well as lead to fatigue and joint pain. Fat-soluble vitamins (A, D, E, K) can accumulate in our fat cells in the body rather than being excreted, and therefore dosage needs to be considered. Even water-soluble nutrients can cause problems in excess. Too much vitamin C can trigger digestive upset and at high doses may lead to kidney stones in susceptible individuals. Excessive niacin (B3) may cause uncomfortable flushing and potential liver stress.
An Individualised Approach
A qualified practitioner who has been properly trained in the prescription of supplements does not just consider the nutrient alone. They assess your individual biochemistry, health history, current medications, existing supplements, and dietary intake. They calculate cumulative nutrient loads from different supplements, identify potential interactions, and select forms and doses that are both safe and effective for your specific situation. Additionally, blood test results, genetic profiles, and symptom assessment all inform these decisions. What works brilliantly for one person might be completely wrong for another with the same condition but different underlying factors.
Final Thoughts
Working with a qualified practitioner, such as a Certified Practicing Nutritionist, ensures you receive the right nutrient, in the right form, at the right dose, without dangerous interactions or excesses. While retail supplements may suit basic nutritional support for generally healthy individuals, targeted therapeutic outcomes require a more sophisticated, personalised approach.
Your health deserves more than guesswork. It deserves professional guidance that considers the complete picture of your wellbeing. The financial investment in high quality practitioner-only supplements and professional advice often saves money in the long run by actually addressing your health concerns effectively and safely, rather than building up a cupboard full of supermarket supplements that may not work, or worse, cause you harm.
Are you looking for someone to support you with your 2026 health and wellness goals?
Consider booking in a 1:1 Clinical Nutrition appointment where together we can develop a personalised nutrition plan that supports your unique health goals. This incorporates dietary and lifestyle recommendations, and practitioner-only supplements where indicated.
Katie practices at: Uprise Health, 136 Lennox Street, Richmond, 3121, Victoria.
Appointments: Face-to-face and Telehealth available (Australia wide)
Contact: admin@katiehopcraft.com.au
If you have any questions or need personalised guidance, feel free to reach out.
The information provided in this blog is for your personal or other non-commercial, educational purposes. It should not be considered as medical or professional advice. We recommend you consult with a GP or other healthcare professional before taking or omitting to take any action based on this blog. While the author uses best endeavours to provide accurate and true content, the author makes no guarantees or promises and assumes no liability regarding the accuracy, reliability or completeness of the information presented. The information, opinions, and recommendations presented in this blog are for general information only and any reliance on the information provided in this blog is done at your own risk.