Keep mcg RAE attached to the vitamin A value
Preserve the RAE unit when copying vitamin A, compare matching portions, and leave an old IU value unresolved when its vitamin A sources are unknown.
A vitamin A entry copied as just 250 mcg loses useful information if the original label said 250 mcg RAE. The letters belong with the number. Keep them when making a shopping note, checking a scan or comparing a current label with an older product photograph.
What RAE tells you
RAE means retinol activity equivalents. The NIH Office of Dietary Supplements vitamin A fact sheet explains that this unit accounts for differences in the activity of retinol and provitamin A carotenoids. For example, 1 mcg RAE corresponds to 1 mcg retinol or 12 mcg beta-carotene from food. Those are different substances and amounts expressed on a common activity basis; RAE is not another spelling of the physical mass of every vitamin A ingredient.
Build a comparison that keeps its meaning
Imagine two fictional cereal labels, each giving values per 40 g of dry cereal. Product A lists vitamin A as 250 mcg RAE and product B as 300 mcg RAE. A useful record looks like this:
| Field | Product A | Product B |
|---|---|---|
| Food basis | 40 g dry cereal | 40 g dry cereal |
| Vitamin A value | 250 | 300 |
| Complete unit | mcg RAE | mcg RAE |
The declared difference is 50 mcg RAE on that shared basis. This is a comparison of the label entries, not a reason to choose the larger number. If one panel instead describes cereal prepared with milk, pause: the portion description must also match before subtracting the values.
An old IU photograph needs more information
Now suppose an archived label says 1,000 IU of vitamin A. Do not place 1,000 in the same column as 250 and 300. NIH's conversion guidance depends on the vitamin A source. In a hypothetical record explicitly documenting that all 1,000 IU come from retinol, its factor of 0.3 mcg RAE per IU gives 300 mcg RAE. That result cannot be assigned to a record whose source or mixture is unknown.
Keep the original IU entry and write source information missing. A current package or a manufacturer explanation of that exact formulation may resolve the gap. A familiar ingredient name without its contribution does not necessarily resolve a mixed-source calculation.
Keep the package available when using an app
For everyday food-label reading, download Ingredi AI from its official Apple listing or official Google Play listing, subject to availability on your device. Check any captured vitamin A entry against the full printed unit. This worksheet does not establish that an app can resolve unknown forms, and it does not recommend a vitamin A intake or supplement dose.