Daily vitamin and mineral intake for adults
RDA (Recommended Dietary Allowance) meets the needs of nearly all healthy adults; AI (Adequate Intake) is used where the evidence for an RDA is not yet strong enough. The amounts below are the US National Academies DRI for healthy adults aged 19–50 and assume average needs — pregnancy, older age and some diets change them.
| Nutrient | Men (19–50) | Women (19–50) | Notes |
|---|---|---|---|
| Vitamin A | 900 µg RAE | 700 µg RAE | Upper limit 3,000 µg RAE |
| Vitamin C | 90 mg | 75 mg | Smokers: add 35 mg/day |
| Vitamin D | 15 µg (600 IU) | 15 µg (600 IU) | 800 IU (20 µg) after age 70 |
| Vitamin E | 15 mg | 15 mg | As alpha-tocopherol |
| Vitamin K | 120 µg | 90 µg | AI; gut bacteria also make some |
| Vitamin B6 | 1.3 mg | 1.3 mg | Rises after 50 (men 1.7 mg, women 1.5 mg) |
| Vitamin B12 | 2.4 µg | 2.4 µg | Vegans and older adults often need supplements |
| Folate | 400 µg DFE | 400 µg DFE | 600 µg DFE in pregnancy |
| Calcium | 1,000 mg | 1,000 mg | 1,200 mg for women 51+ and men 71+ |
| Iron | 8 mg | 18 mg | 18 mg for ages 19–50; 8 mg after menopause |
| Zinc | 11 mg | 8 mg | Higher in pregnancy and breastfeeding |
| Magnesium | 400–420 mg | 310–320 mg | Higher amount for ages 31+ |
Notes
- General reference, not individual advice — ask a doctor or dietitian before starting supplements.
- Amounts are US National Academies Dietary Reference Intakes; EU, WHO and other national figures differ slightly, so check official local guidance.
- Every nutrient has an upper limit (UL): more is not better. Prefer food sources over pills where you can.
Frequently asked questions
- What is the difference between RDA and AI?
- An RDA (Recommended Dietary Allowance) meets the needs of nearly all healthy people in a group. An AI (Adequate Intake) is set when there is not enough evidence for an RDA, and it is used as a target.
- Do adults need a daily multivitamin?
- Most healthy adults get enough from food. Supplements commonly matter for vitamin D, vitamin B12 (vegans and older adults), iron and folate in pregnancy — ask a clinician first.
- What is the daily vitamin D dose in IU?
- The US RDA is 600 IU (15 µg) per day up to age 70 and 800 IU (20 µg) after 70. Many specialists aim for higher blood levels, so follow your own test results and medical advice.
- Which minerals do adults most often lack?
- Iron in premenopausal women, calcium in older women and magnesium in many adults. A blood test can confirm a true deficiency before you supplement.