Elemental vs salt-form dosing

Written by Cassie, registered pharmacist
Founder of Clean Green Safe

Minerals on a supplement label are often listed as a compound, and the number you see isn’t always the amount of the mineral itself. It’s one of the most common sources of confusion on a label, so it’s worth taking a moment to understand.

Compound form vs elemental amount

Minerals are often listed as a compound, such as magnesium oxide, zinc sulfate or calcium carbonate. The compound is the mineral plus the rest of the molecule it’s bound to. The elemental amount is just the mineral, and that’s the part that counts toward your daily nutritional target.

Why you may see both

A label might show “magnesium oxide 500 mg” (the compound), “elemental magnesium 300 mg” (the mineral), or both. When only the compound is shown, you can work out the elemental amount using a conversion factor.

Conversion factors

Each compound has its own conversion factor, based on how much of its weight is the mineral. Magnesium oxide is about 60% elemental magnesium, while magnesium citrate is about 16%. So two products with the same number on the front can contain quite different amounts of magnesium.

Finding the amount that counts

When you compare a serve to your daily nutritional target, use the elemental amount rather than the compound weight. Clean Green Safe does this conversion for you where the label gives a compound, and your pharmacist can help if you’d like to talk it through.

ABOUT THE AUTHOR

Cassie, registered pharmacist

Cassie is a registered pharmacist, a parent and the founder of Clean Green Safe. With a background in Australian supplement regulation across the TGA, FSANZ and NHMRC, she built Clean Green Safe to help people understand what’s really in their supplements, and how it all adds up across everything they take.