Zinc labels: one nutrient, several salts
Why zinc labels name different compounds, and how the elemental zinc row and NRV column keep them comparable.
The same nutrient arrives in different compounds
Zinc is never sold as bare metal. Labels name a salt or a chelate instead, and several are in common use.
Each compound carries its own proportion of zinc by weight, which is why the ingredients list and the nutrient panel rarely show matching numbers.
- Zinc citrate, zinc gluconate, zinc bisglycinate, zinc picolinate, zinc sulfate and zinc oxide.
- The compound appears in the ingredients list.
- The elemental zinc appears as a nutrient panel row.
Elemental zinc is the figure to compare
The nutrient panel row headed zinc is already expressed as elemental zinc per stated portion. That is the number to carry across to another product.
A compound weight quoted on the front of a pack is not wrong, but it is not comparable to another brand's elemental figure.
Tablet weight tells you almost nothing
A tablet also contains bulking agents, binders, anti caking agents and sometimes a coating. Its total weight is a manufacturing fact, not a nutrient fact.
Two tablets of identical weight can declare different zinc rows, and the smaller tablet is not automatically the smaller figure.
What the NRV percentage means here
Nutrient reference values are fixed reference figures set in law, one per nutrient. The percentage states the portion against that reference and nothing more.
It is useful precisely because it is calculated from the elemental amount, so it crosses compound boundaries cleanly.
Ninety tablets is a pack size, not a duration
The pack is listed as 90 tablets. Until the label states how many tablets make a portion, that count cannot be turned into portions or days.
Cost per tablet and cost per portion are different sums, and only the second one compares two products fairly.
What the label tells you
The full ingredients list, the amount per portion, allergens, dietary suitability, directions and storage are printed on the pack.
Read the label before you take any supplement, and check the product page for the format, pack size and price before you buy.
