Vitamin Intake Reference Calculator

This calculator looks up an adult dietary reference amount for one selected vitamin. It covers people aged 19 and older and uses the age and sex categories in the United States Dietary Reference Intakes. The result is a daily reference for generally healthy people, not a prescription for a supplement.

Some nutrients have a Recommended Dietary Allowance (RDA), while vitamin K, biotin, pantothenic acid and choline use an Adequate Intake (AI). The page labels that basis in the result. Pregnancy, breastfeeding, diagnosed deficiency, absorption problems, medicines and other clinical circumstances can change what is appropriate.

1. Choose the sex category used by the adult reference table.
2. Enter a whole age from 19 through 120 years.
3. Select the vitamin or choline entry you want to check.
4. Choose Calculate and read both the amount and its unit.
5. Confirm whether the displayed basis is RDA or AI before comparing it with a label.

Use the unit exactly as shown. Milligrams and micrograms differ by a factor of 1,000, and vitamin D is displayed in international units with its microgram equivalent. The lookup changes vitamin D at age 71 and vitamin B6 after age 50.

Compare food and supplement labels only after putting every source in the same unit. Add amounts from all products if you are reviewing total supplemental intake.

Treat the number as a population reference for usual daily intake. It is useful for reading labels, checking a food log or understanding the scale of an adult recommendation. It is not a minimum that must be hit perfectly every day; dietary patterns are usually considered over time.

An RDA and an AI are not upper limits. The tolerable upper intake level, when one exists, answers a different question about the highest average daily intake unlikely to create adverse effects. Do not assume that taking more than the displayed amount provides more benefit.

Food labels may use Daily Values, which support product labelling and can differ from the age- and sex-specific DRI shown here. Check the label unit and reference system before deciding that two numbers disagree.

Chemical form matters for some nutrients. Folate may be expressed as dietary folate equivalents, vitamin A may use retinol activity equivalents, and vitamin E recommendations refer to alpha-tocopherol. A simple amount cannot always be compared across forms without an appropriate conversion.

A diagnosed deficiency is managed differently from routine nutrition planning. Laboratory results, symptoms, medicines and the cause of low status can influence treatment. High-dose vitamin A, D, E or K and some B-vitamin products can have meaningful risks or interactions.

Older adults receive a higher vitamin D reference on this page from age 71. Vitamin B6 also changes after age 50. Other listed values remain fixed because that is how this limited adult lookup is implemented, not because every person has identical needs.

Keep a written list of supplements and fortified products. Duplicate ingredients are easy to miss when a multivitamin, single-nutrient tablet and fortified drink are used together. A pharmacist or dietitian can review the combined amounts.

The page does not estimate intake from food and does not assess diet quality. Use it as a reference alongside reliable food composition data and individualized professional advice when health conditions are involved.