Supplements with judgement: What a supplement is, what may be said and what to ask first

What it is

A food supplement is a food, not a medicine: it provides nutrients or other substances with a nutritional or physiological effect, and it cannot be presented as preventing, treating or curing a disease. That border is the one most often crossed by fads: creatine, magnesium or ashwagandha are sold with promises the law does not allow.

At the counter it matters for three reasons. First, whoever asks about a supplement almost always has a symptom or a goal behind it, and a symptom has to be assessed. Second, a supplement can interact with what the person already takes. And third, what can be claimed is regulated: in the EU only authorised health claims are valid, with their conditions of use.

The framework, in four ideas

What separates a supplement from a medicine is not the capsule, it is the regime:

FOOD: it is notified to the authority before being marketed, but it is not authorised for efficacy the way a medicine is.
CLAIMS: only those in the European register of health claims can be used, with the condition of use (dose, population) each one sets. Any other is an unauthorised promise.
NO DISEASE: it cannot say that it prevents, treats or cures a disease, or suggest it. "Supports diabetes" or "for anxiety" turn the product into something the law treats as a medicine.
VIGILANCE: adverse effects are reported to the monitoring systems for foods; your report counts just the same.

At the counter

When to recommend it

When there is a measured deficiency or a recognised risk group (for example, vitamin D in older people with little sun exposure)
When the diet falls short and the person knows it and says so
When the goal is specific, reasonable and can be checked within a few weeks

When not to

When it is requested to "cure" or "make up for" a disease or a treatment
When there are unassessed symptoms or the person is trying to avoid seeing a doctor
When the product promises something no supplement can: effortless weight loss, "detox", rejuvenation

What to say at the counter. Listen to the reason first, ask what they already take and say only what is authorised. A good supplement recommendation is short, specific and comes with a review date.

Warnings

Important A supplement does NOT replace any treatment or delay a consultation. If there are symptoms, refer.
Important Be careful with "sports" supplements: without quality control they can contain undeclared substances, and a positive anti-doping test is not defended by saying it was a supplement.
Caution More is not better: adding several products with the same nutrient (vitamins, magnesium, caffeine) reaches high doses without anyone having decided it.

Six questions before recommending anything

Why do they think they need it? If there are symptoms (tiredness, tingling, hair loss, low mood), assess first and refer if needed: a supplement is not a diagnosis.
What do they already take? Medicines and other supplements: the total dose and the interactions matter more than each product alone.
Are they pregnant, breastfeeding or a minor? Do they have kidney, liver or thyroid disease or an upcoming operation? Many supplements "have no data" in these cases, and that is a reason not to recommend them.
Do they compete under anti-doping control? Supplements can be contaminated with prohibited substances: without a quality guarantee, better not.
What can you say? Only what is authorised. Everything else is explained as limited evidence or as "not proven".
For how long? A supplement is a trial with an end date: review it at 8-12 weeks and stop if there is no reason to continue.

Food supplement and medicine

Aspect	Food supplement	Medicine
What it is	A food with nutritional or physiological purposes	A product for prevention, diagnosis or treatment
How it reaches the market	Notified to the authority; no efficacy authorisation	Prior authorisation after showing quality, safety and efficacy
What it may claim	Only authorised claims, and never about disease	The indications in its summary of product characteristics
How it is supplied	Over the counter	With or without prescription depending on the case
If something goes wrong	Reported to the food monitoring systems	Pharmacovigilance

If a product promises to treat a disease, it is no longer a supplement: it is an unauthorised medicine.

Self-assessment

Three questions. When you check your answers you will see the explanation for each one.

A customer asks for a supplement "for anxiety". What do you do first? Recommend the best seller Ask about the reason and, if the symptoms worry them, refer; a supplement does not treat anxiety Tell them it is a natural treatment
Which health claims can a supplement use in the EU? Only those authorised in the European register, with their condition of use Any, if there is a study Whatever the manufacturer thinks is true
An athlete under anti-doping control asks about a supplement. What do you say? That they should take it with water That it may be contaminated with prohibited substances and that, without a quality guarantee, it is better not to take it That if it is natural there is no risk

Training content. It does not replace the summary of product characteristics or clinical judgement.

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