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Add the supplements you take. We add up each vitamin and mineral and show it next to its upper limit: the most a day that is unlikely to cause harm for almost everyone your age.
Limits from the U.S. National Academies (the values the NIH uses). Labels from the NIH Dietary Supplement Label Database. Free, no sign-up. Your list stays in this browser.
Men and women have the same limits. For adults, only the calcium and phosphorus limits change with age.
Type the brand and name from the front of the bottle. We search 100,000+ U.S. labels in the NIH label database.
Or pick one vitamin or mineral:
3. Your results
Your results will show here: each vitamin and mineral you take, next to its daily upper limit.
How the checker works
- The tolerable upper intake level (UL) is the most of a nutrient a day that is unlikely to harm almost anyone in an age group. The limits are the U.S. Dietary Reference Intakes set by the National Academies of Sciences, Engineering, and Medicine (the same values the NIH Office of Dietary Supplements and Health Canada list). A limit is a ceiling, not a target: above it, the chance of side effects goes up.
- For most nutrients the limit counts food and supplements together; the checker only adds your supplements, so your real total is higher. For magnesium, folic acid, niacin and vitamin E the limit is for supplements and fortified foods only.
- Product amounts come from the NIH Dietary Supplement Label Database, a public record of U.S. supplement labels, which your browser searches directly. Labels change: check the amounts against your bottle. Nothing you type or add is sent to us.
- No upper limit is set for some nutrients (for example vitamin B12 and biotin): the checker shows the total and says so.
- The limits are data, not advice, and no AI writes or changes this checker.
Upper limits for adults, by nutrient
| Nutrient | Upper limit, ages 19 to 50 | Counts |
|---|---|---|
| Vitamin A | 3,000 mcg (10,000 IU) | Food and supplements (retinol only) |
| Vitamin C | 2,000 mg | Food and supplements |
| Vitamin D | 4,000 IU (100 mcg) | Food and supplements |
| Vitamin E | 1,000 mg | Supplements only |
| Vitamin K | Not set | No limit set |
| Thiamin | Not set | No limit set |
| Riboflavin | Not set | No limit set |
| Niacin | 35 mg | Supplements only |
| Vitamin B6 | 100 mg | Food and supplements |
| Folic Acid | 1,000 mcg | Supplements only |
| Vitamin B12 | Not set | No limit set |
| Pantothenic Acid | Not set | No limit set |
| Biotin | Not set | No limit set |
| Choline | 3,500 mg | Food and supplements |
| Calcium | 2,500 mg | Food and supplements |
| Magnesium | 350 mg | Supplements only |
| Phosphorus | 4,000 mg | Food and supplements |
| Potassium | Not set | No limit set |
| Iron | 45 mg | Food and supplements |
| Zinc | 40 mg | Food and supplements |
| Copper | 10 mg | Food and supplements |
| Selenium | 400 mcg | Food and supplements |
| Iodine | 1,100 mcg | Food and supplements |
| Manganese | 11 mg | Food and supplements |
| Molybdenum | 2,000 mcg | Food and supplements |
| Chromium | Not set | No limit set |
| Boron | 20 mg | Food and supplements |
From age 51 the calcium limit is 2,000 mg; from age 71 the phosphorus limit is 3,000 mg. Each nutrient’s page has the limits for every age group, pregnancy and breastfeeding.
If you think you or a child took too much of a supplement, call Poison Control at 1-800-222-1222 (U.S., free, 24 hours) or use poison.org. In an emergency, call 911.
Sources: National Academies Dietary Reference Intakes; Health Canada Dietary Reference Intakes tables (the joint U.S.-Canada values); NIH Dietary Supplement Label Database. Limits checked November 8, 2026.
General information, not medical advice. Your doctor may recommend a different amount, for example to treat a deficiency. Talk to your doctor or pharmacist before you start, stop or change a supplement, especially if you are pregnant, nursing, take medication or have a medical condition.