Vitamin D and the Sun: What the NIH Says
Tick what applies to you and read what the NIH Office of Dietary Supplements says, word for word. No minutes in the sun and no supplement amounts: those belong with your doctor.
What the NIH says for you
- NIH Office of Dietary Supplements: "Because you get vitamin D from food, sunshine, and dietary supplements, one way to know if you’re getting enough is a blood test that measures the amount of vitamin D in your blood."
- NIH Office of Dietary Supplements: "Ultraviolet radiation from sunshine can cause skin cancer, so it’s important to limit how much time you spend in the sun."
- WHO: "Artificial tanning should never be considered as an option to achieve sufficient vitamin D status."
- NIH Office of Dietary Supplements: "We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health."
This page gives no time in the sun and no supplement amount. Take these lines to your doctor, who can test your level. Sources: NIH Office of Dietary Supplements, WHO.
Sun, food and a blood test
“Your body makes vitamin D when your bare skin is exposed to the sun. Most people get at least some vitamin D this way. However, clouds, smog, old age, and having dark-colored skin reduce the amount of vitamin D your skin makes. Also, your skin does not make vitamin D from sunlight through a window.”
“Ultraviolet radiation from sunshine can cause skin cancer, so it’s important to limit how much time you spend in the sun.”
“Fatty fish (like trout, salmon, tuna, and mackerel) and fish liver oils are among the best natural sources of vitamin D.”
NIH Office of Dietary Supplements, Vitamin D consumer fact sheet, checked October 6, 2026.
Frequently Asked Questions
How long should I be in the sun for vitamin D?
This page does not say, and no page on this site will. The NIH Office of Dietary Supplements says: "Ultraviolet radiation from sunshine can cause skin cancer, so it’s important to limit how much time you spend in the sun." Until October 6, 2026 this tool printed a number of minutes; it was removed.
How do I know if I'm getting enough?
The NIH Office of Dietary Supplements: "Because you get vitamin D from food, sunshine, and dietary supplements, one way to know if you’re getting enough is a blood test that measures the amount of vitamin D in your blood." Your doctor can order that test.
Can a tanning bed help?
No. WHO: "Artificial tanning should never be considered as an option to achieve sufficient vitamin D status."
Should I take a supplement, and how much?
That is a question for your doctor, not a website. The NIH Office of Dietary Supplements: "We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health."
General information, not medical advice. Talk to your doctor before relying on the sun for vitamin D or starting a supplement.