Almost everything on the back is law
The front of a supplement pack is marketing. The back is a regulated document, set by Directive 2002/46/EC and Regulation (EU) No 1169/2011 on food information to consumers. Both texts are public and neither is long.
Once you know the structure, any bottle in your cupboard takes about a minute to read properly. This is the structure.
The five statements that have to be there
Article 6(3) of Directive 2002/46/EC requires five things on every food supplement sold in the EU:
- The names of the categories of nutrients or substances that characterise the product.
- The portion recommended for daily consumption: one drop, two capsules, half a scoop.
- A warning not to exceed that stated dose.
- A statement that supplements are not a substitute for a varied and balanced diet.
- A statement to keep the product out of the reach of young children.
The second matters more than it looks. Every other number on the label is expressed per that portion, so two products can look identical until you notice one portion is a single capsule and the other is three.
The nutrition panel: an amount, then a percentage
Article 8 of the same directive requires the amounts of nutrients to be declared in numerical form, per the recommended daily portion, and also as a percentage of a reference value. So you get two numbers for each nutrient, and they are not interchangeable.
NRV is a labelling yardstick, not a recommendation for you
NRV stands for Nutrient Reference Value, and the values are listed in Annex XIII of Regulation (EU) No 1169/2011. For vitamin D the NRV is 5 µg; for vitamin K, 75 µg. One figure each for the whole adult population, chosen so two products can be compared on a shelf.
It is not a personal target, not a ceiling, and not adjusted for your age, weight or diet. Which is why a percentage alone tells you very little. A product declaring 500% of the NRV for vitamin D contains 25 µg — five micrograms times five. Read the micrograms first.
Percentages are also only comparable within one nutrient. 500% of the vitamin D NRV and 27% of the vitamin K NRV are 25 µg and 20 µg: nearly the same quantity of material, wildly different percentages, because the two reference values are fifteen times apart.
Micrograms and international units
For vitamin D you will often see two units side by side. The conversion is fixed: 1 µg of vitamin D is 40 IU. So 25 µg is 1,000 IU, and 10 µg is 400 IU.
Only one of them is the legal declaration. EU labelling requires vitamin D in micrograms; IU appears alongside because a great many people learned the numbers that way and would not recognise 25 µg as the same quantity. A label giving IU only is either not a European label or not a complete one.
Two things to watch. µg is sometimes written mcg: same unit. And µg is not mg — a thousandfold error, one letter away.
The ingredient list
A percentage in the ingredient list is not a dose
Ingredients are listed in descending order of weight under Article 18 of Regulation (EU) No 1169/2011. A percentage beside an ingredient is a proportion of the finished product by weight — a quantitative ingredient declaration, which Article 22 makes compulsory in certain cases and which some manufacturers print on every line anyway.
It answers a different question from the nutrition panel. Our label reads: MCT from coconut oil 96.5%, cholecalciferol 2.5%, menaquinone-7 1%. The panel says 25 µg of vitamin D3 and 20 µg of vitamin K2 per drop. Both are true. The percentage says what the bottle is made of; the micrograms say what a dose contains.
Three lines or eleven
A short list is not automatically a better product, and a long one is not automatically worse. Length is mostly a consequence of format. An oil needs a carrier, because vitamin D and vitamin K are fat-soluble and will not disperse in water; that carrier is the bulk of the bottle and one line on the label. A powder machine-filled into a capsule has to occupy a sensible volume and flow reliably, which is two or three more lines before you have counted the shell. A tablet has to be compressed, held together, then broken apart again after swallowing, which is a few more.
So the useful question is not how many ingredients. It is: how many are here because of the format, and how many instead of the active?
Bulking agent, anti-caking agent, and the rest
Additives are not named freehand. Under Annex VII of Regulation (EU) No 1169/2011 each is designated by its functional class followed by its specific name or E number. The class is the useful half, because it names the job:
- Bulking agent — adds volume without adding active. You cannot fill a capsule with 25 µg of powder; there is not enough of it to handle. Something has to occupy the space. Microcrystalline cellulose (E460), rice flour.
- Anti-caking agent — keeps a powder loose and free-flowing so every capsule receives the same fill weight. Silicon dioxide (E551), magnesium salts of fatty acids (E470b).
- Binder, disintegrant, lubricant — the tablet trio: hold the compressed mass together, make it fall apart again once swallowed, stop it welding itself to the press.
None of these is a red flag on its own. A capsule containing them is not adulterated; it is a capsule. What they are is evidence about the format — and once you know what a format requires, a list of eleven tells you quickly whether the extra eight are engineering or padding.
The two numbers at the bottom
A best-before date and a lot or batch mark. The batch mark is the more interesting: it is the only thing on the pack tying your bottle to one production run, and to whatever was tested in it. If a seller publishes a certificate of analysis, check the batch on it before you read a single result.
What a label may not say
Health claims about food are governed by Regulation (EC) No 1924/2006: a claim may only be made if it is on the EU Register of nutrition and health claims, and only in the authorised wording. The register holds nine sentences for vitamin D and vitamin K, all nine set out in our article on why the two are sold together. Anything broader is not a bolder version of the same idea; it is outside what the register permits. Separately, Article 7(3) of Regulation (EU) No 1169/2011 forbids food information from attributing to any food the property of preventing, treating or curing a human disease.
The order to read it in
- Find the recommended daily portion. Everything else is per that.
- Read the amount per portion in micrograms or milligrams. Then the percentage.
- Read the ingredient list top to bottom. Sort the format from the active.
- Check the batch mark and the best-before date.
- Multiply the portion by the days you intend to take it, and see whether the pack holds that much.
Five steps, about a minute, and it works on any pack. Ours included.