Guide
The %DV and the upper limit: what the two numbers mean
Two reference numbers frame every vitamin and mineral amount: the Daily Value, printed on the label as a percentage, and the Tolerable Upper Intake Level, which is not on the label at all. They answer different questions.
Published ยท Last updated
Written with AI tools under the editorial policy. Every figure is read from the label database, not written by the model.
The Daily Value: a labelling yardstick
The FDA sets one Daily Value per nutrient for labels (21 CFR 101.9), mostly based on the highest recommended intake across adults and children 4 and older, so one yardstick fits every label. It is not a target for any one person. A label's %DV is simply the amount divided by that yardstick. Separate Daily Values exist for infants, children under 4, and pregnancy and lactation, used on products made for those groups.
The upper limit: the safety ceiling
The Tolerable Upper Intake Level (UL) comes from the National Academies (Institute of Medicine tables, 2011): the highest daily intake unlikely to harm almost any healthy adult. It counts intake from all sources unless the nutrient's note says otherwise: magnesium's UL covers supplements and medicines only, and niacin's and folic acid's cover the synthetic forms. Children's limits are lower. Some nutrients have no UL, which means the evidence was not enough to set one, not that any amount is safe.
The two side by side
| Nutrient | Daily Value | Adult UL | Median on labels |
|---|---|---|---|
| Vitamin D | 20 mcg | 100 mcg | 15 mcg |
| Vitamin C | 90 mg | 2,000 mg | 100 mg |
| Vitamin B6 | 1.7 mg | 100 mg | 6 mg |
| Zinc | 11 mg | 40 mg | 11 mg |
| Magnesium | 420 mg | 350 mg | 86 mg |
| Niacin | 16 mg | 35 mg | 20 mg |
| Iron | 18 mg | 45 mg | 5 mg |
| Calcium | 1,300 mg | 2,500 mg | 115 mg |
Sources: 21 CFR 101.9(c)(8)(iv); Institute of Medicine (2011); NIH Dietary Supplement Label Database, current labels.
Figures: NIH ODS Dietary Supplement Label Database, version 9.4.0, current labels.
How far labels go past each
For 11 of the 24 nutrients with a Daily Value, the median product lists more than the DV in one serving. Vitamin B12 goes furthest: the median product lists 14.6 times its Daily Value. For B vitamins and vitamin C, amounts well above the DV are the norm, and their ULs (where set) are far higher still.
The upper limit is passed far less often, but not rarely. Counting the most servings a day each label allows, 8,383 products list at least one nutrient above the adult UL; niacin leads, at 35% of products giving its amount. The upper-limit analysis lists every nutrient.
Figures: NIH ODS Dietary Supplement Label Database, version 9.4.0, current labels.
Reading the two on a product page
On every PlainVitamins product page, each amount is drawn against all products listing the same ingredient, with the Daily Value marked in green and the adult UL as a red dashed line. An amount past the UL is a fact about the label, not a verdict on the product: a clinician may advise more for a reason, and a limit that counts all sources says nothing about a person who gets little from food. Ask a physician, pharmacist or registered dietitian before taking more than the UL.
Where next?
- Amounts against the Daily ValueEvery nutrient with a DV, the median and the share above 5x.
- Labels above the upper limitWhich nutrients pass the adult UL, and on which products.
- Check an amountType an amount; see where it sits against the market, the DV and the UL.