How to Read This Vitamin & Mineral Table
The numbers in the table above answer one practical question: roughly how much of each nutrient does a healthy person in your age and sex group need in a day, and how much is too much? The two figures that matter most are the RDA (or AI) and the UL. The RDA is a target — the amount that covers the needs of nearly everyone who is healthy. The UL is a ceiling — the point above which routine intake starts to carry a real risk of harm. The comfortable zone for most people is the band between meeting the RDA from food and staying well under the UL. You almost never need to hit the UL, and there is no bonus for exceeding the RDA.
A few values appear as an AI (Adequate Intake) rather than an RDA. This simply means the scientific evidence was not strong enough to set a formal RDA, so experts estimated an intake level that appears sufficient based on what healthy populations actually consume. Treat an AI the same way you would an RDA: as a reasonable daily target. Where you see ND (Not Determined) in the upper-level column — as with vitamin K — it means no toxicity threshold has been established from food, not that unlimited intake is safe.
Fat-Soluble vs. Water-Soluble: Why It Matters
Vitamins fall into two groups that behave very differently in the body. Fat-soluble vitamins — A, D, E, and K — are stored in the liver and fatty tissue. Because your body holds onto them, they accumulate, and taking large supplemental doses over weeks or months is the most common way people develop a genuine vitamin toxicity. This is why the upper limits for vitamin A and vitamin D deserve respect: the danger is rarely from food, but high-dose supplements can push you past the line.
Water-soluble vitamins — the B-complex vitamins and vitamin C — are not stored in significant amounts; excess is mostly filtered out by the kidneys and excreted in urine. That makes them harder to overdose on, but "hard" is not "impossible." Very high doses of vitamin B6 can cause nerve damage, and large doses of vitamin C can trigger digestive upset and contribute to kidney stones in susceptible people. The minerals are a separate category again: iron, zinc, selenium, and others can accumulate and become toxic, which is why iron supplements in particular are a leading cause of accidental poisoning in young children.
Who Is Most Likely to Fall Short
Most healthy adults who eat a varied diet meet the majority of these targets without thinking about them. Shortfalls tend to cluster around specific life stages and circumstances rather than being universal. People with limited sun exposure, darker skin, or who live at higher latitudes commonly run low on vitamin D. Those following a strict vegan diet need a reliable source of vitamin B12, which is found almost exclusively in animal foods. Anyone who is pregnant or trying to conceive is advised to get adequate folate to reduce the risk of neural tube defects — notice how the pregnancy and breastfeeding columns in the table above raise the targets for several nutrients. Menstruating women, frequent blood donors, and endurance athletes are more prone to low iron. Older adults often absorb B12 and vitamin D less efficiently and may eat less overall.
The point of knowing your group's reference values is not to diagnose yourself, but to recognize when a conversation with a doctor or dietitian — backed by an actual blood test — is worth having. A reference table cannot tell you whether you are deficient; only testing can.
Food First, Supplements Second
Nutrition research consistently favors getting nutrients from whole foods rather than pills. Food delivers vitamins and minerals alongside fiber, healthy fats, and other compounds that improve absorption and provide benefits a single isolated nutrient cannot replicate. A supplement is a useful tool for closing a documented gap — a confirmed deficiency, a dietary restriction, pregnancy, or an absorption disorder — but it is a poor substitute for an otherwise adequate diet. When a supplement is warranted, two habits reduce risk: count both food and supplement sources toward your daily total so you don't unknowingly stack past the UL, and choose products carrying a third-party verification mark such as USP or NSF, since supplements are loosely regulated and label accuracy varies between brands.
Finally, remember that some supplements interact with prescription medications. High-dose vitamin K can blunt the effect of the blood thinner warfarin; vitamin E and certain other supplements can increase bleeding risk; and minerals like calcium and iron can interfere with the absorption of some drugs. If you take any regular medication, clear new supplements with your pharmacist or physician first. The values on this page are a starting point for an informed discussion — not a personalized prescription.