What this calculator shows
Recommended daily intakes for the vitamins and minerals most commonly tracked — vitamins A, C, D, E and K, calcium, iron, zinc and magnesium — for your age group and sex. These figures follow published Recommended Dietary Allowances (RDAs), the values set by national health authorities to cover the needs of nearly everyone in a given group, not a personalised target based on your actual diet or health.
What RDA actually means
An RDA is set high enough to meet the needs of about 97–98% of healthy people in that age and sex group — it is a population safety margin, not the exact amount any one individual needs. Most healthy people need somewhat less than the RDA and are still perfectly adequately nourished; the RDA is calibrated so that meeting it covers almost everyone, at the cost of being more than most people strictly require.
| Term | Meaning |
|---|---|
| RDA — Recommended Dietary Allowance | Meets the needs of ~97–98% of healthy people in the group |
| AI — Adequate Intake | Used when there isn't enough evidence to set a formal RDA; a reasonable estimate instead |
| UL — Tolerable Upper Intake Level | The highest daily amount unlikely to cause harm — not a target, a ceiling |
Why age and sex change the numbers
- Iron requirements are markedly higher for people who menstruate, due to regular blood loss, and drop after menopause to roughly the same level as for men.
- Calcium and vitamin D needs rise in older adults, reflecting slower absorption and increasing bone density loss with age.
- Pregnancy and breastfeeding substantially raise the requirement for several nutrients at once, particularly iron, folate and iodine — figures that sit outside the standard adult tables and need a source specific to pregnancy.
- Growing children and teenagers have requirements that scale with growth rate rather than body size alone, which is why the age brackets are narrower in childhood than in adulthood.
What this is not
It reports population targets, not a nutritional analysis of what you actually eat. It cannot know your diet, absorption, medications or health conditions, all of which change real requirements — some medications interfere with specific nutrient absorption, and conditions from thyroid disease to gut disorders shift real-world needs well outside these tables. It is a reference point for a healthy diet question, such as roughly how much vitamin D an adult needs, not a substitute for bloodwork or advice from a doctor or dietitian when there is a specific concern about a deficiency or a medical condition.