Daily Vitamin D Intake Calculator
NIH-recommended daily vitamin D intake by age, in IU and mcg.
A general population guideline (NIH RDA), not medical advice — vitamin D deficiency is diagnosed with a blood test, and higher doses are sometimes prescribed under medical supervision.
Recommended daily intake
600 IU
In micrograms
15 mcg
For informational and educational purposes only — not medical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why vitamin D is different from other vitamins
Unlike most vitamins, the body can synthesize vitamin D itself — skin exposed to UVB sunlight produces it directly, which is why it's sometimes called the "sunshine vitamin." That synthesis becomes less efficient with age, which is why the recommendation increases from 600 IU to 800 IU at 71. People with limited sun exposure, darker skin (which synthesizes vitamin D more slowly from a given amount of sun), or who live at higher latitudes often need more from food or supplements to reach these targets.
Frequently asked questions
Why does vitamin D intake matter if sunlight makes it too?
Sun exposure, limited daylight, skin tone, sunscreen use, and geographic latitude all affect how much vitamin D your skin actually produces — dietary and supplemental intake targets exist because sunlight alone is an unreliable source for many people.