Why does an iron supplement have a poison warning?

Most warnings on a supplement bottle are the manufacturer’s own words. This one is not.

The sentence, as written

WARNING: Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6. Keep this product out of reach of children. In case of accidental overdose, call a doctor or poison control center immediately.

The regulation prescribes that text for any dietary supplement in solid oral dosage form containing iron as an iron source.

It also prescribes where it goes: prominently and conspicuously on the information panel of the immediate container. Not the box the bottle came in. For unit-dose packaging, in a way that keeps the warning intact until every dose has been used.

That degree of specificity about placement is unusual, and it tells you what the rule is actually for. Someone thought carefully about a bottle that has lost its carton and is sitting in a bedside drawer.

Why iron specifically

Iron is essential, and it is one of the most commonly supplemented minerals there is, particularly in pregnancy and after blood loss.

The gap between a therapeutic adult dose and a dangerous dose for a twelve kilogram child is not wide, and the tablets are frequently coated, coloured and sweet. That combination, rather than anything unusual about the chemistry, is what produced the rule.

It is the clearest illustration on this site of the point the guide to hazard and exposure makes: the substance is not the danger, the dose and the person are.

What to actually do

If a child has swallowed iron tablets, or you think they might have, this is a poison control centre or an emergency department now rather than a search result. That is what the mandated sentence says and it is not being cautious.

Nothing on this website is a substitute for that call, and a label reader is the wrong tool for an emergency.

While you are looking at the panel

Two things worth reading on Ferrous sulfate and its relatives, since you are already there.

Which salt. The panel names it, as Iron (as ferrous sulfate) or fumarate or gluconate, because supplement labelling requires the source ingredient to be identified.

Elemental iron. The salts carry different amounts of actual iron per milligram of compound, so the elemental figure is the one that compares between products, and it is the smaller number.

The guide to a Supplement Facts panel covers what else that panel is obliged to tell you.