Read the serving before the strength
A bottle that says 5,000 IU is not automatically 5,000 IU per capsule. The number belongs to the labeled serving, and the serving column is where you confirm it: one softgel, one capsule, or — for gummies — often two pieces. Two bottles at the same strength can carry different amounts per unit if their serving sizes differ.
Start with the IU per labeled serving, and note the form the label names (softgel, capsule, gummy). On BasisTrace we display the labeled form rather than scoring which one is better, because the label does not support that comparison.
Put the price on one scale
Divide the quoted package price by the number of servings in the package, then normalize:
For an illustrative calculation only, a $12 package with 120 servings costs $0.10 per serving. If each serving declares 1,000 IU, the calculated cost is $0.10 per 1,000 IU. The same $0.10 serving of a 2,000 IU product would calculate to $0.05 per 1,000 IU. These figures do not describe a listed product.
Know what that number cannot say
A lower cost per 1,000 IU does not establish product quality, purity, absorption or suitability for you. It also says nothing about how much vitamin D you should take — whether you need it, at what dose, and how it interacts with calcium, other supplements or food are medical questions, not label-literacy questions. BasisTrace compares the label's claims and the listed price — nothing more.
Prices change, and an outdated or missing offer cannot support a current unit-cost comparison. Check the source label and the price-check date on each vitamin D3 record, and read our method for the full calculation and evidence policy.