How to read a Supplement Facts panel

Every supplement sold in the US carries a Supplement Facts panel. It's the most useful thing on the bottle, and most people skip it. Here's how to read one, using our Vitamin D3 as the example.

1. Serving size comes first

Everything below it is measured per serving, not per capsule. Our Magnesium Glycinate serving is two capsules, so the 240 mg on the panel is for both together.

2. Amount per serving

This is the dose, written in metric units. Vitamin D3 shows 125 mcg, and because vitamin D is also measured in International Units, the panel lists 5,000 IU alongside it.

3. % Daily Value

%DV compares the amount to a reference intake set by the FDA. The Daily Value for vitamin D is 20 mcg, so 125 mcg is 625%.

4. The dagger (†)

Some ingredients, such as ashwagandha root extract or berberine, have no established Daily Value. The panel marks those with a dagger instead of a percentage.

5. Other ingredients

Below the panel you'll find everything else in the product: the capsule shell, the oil in a softgel, or the flavour in a lozenge. This is where to look if you avoid gelatin or certain additives.

What to watch for on any brand

• “Proprietary blend” with one total weight: you can't see how much of each ingredient is inside.
• The form of the nutrient (for example “as magnesium bisglycinate chelate”). Good labels name it.
• The plant part for botanicals: root, leaf or fruit.