Sun protection
Does daily sunscreen lower your vitamin D?
The old answer was no. A 2025 randomized trial of daily SPF 50+ found it does raise deficiency risk. The fix is a supplement, not less sunscreen.
- Levels did fallHigher deficiency risk in the sunscreen group
- Diligent users, not casualThin occasional use still looks different
- Replace the vitaminA supplement is cheap; UV damage is permanent
On this pageThe answer that held for years5
Quick answer
The bottom line
The honest answer changed recently. For years the evidence said real-world sunscreen use did not meaningfully lower vitamin D, and that reassurance was reasonable at the time. A randomized trial published in 2025 that asked Australian adults to apply SPF 50 or higher routinely for about a year found lower blood levels and a higher risk of deficiency in the sunscreen group, and the effect persisted in people not taking supplements. That is a real finding and it does not argue for less sun protection. Vitamin D is trivially cheap to replace with a supplement or through diet; the ultraviolet damage you would take to get it from sunlight is not reversible. Keep the sunscreen, and ask about a blood test or a supplement if you use it daily.
At a glance
Three things worth remembering
- A randomized trial of routine high-SPF use over about a year found lower vitamin D levels and a higher risk of deficiency in the sunscreen group.[1]
Section 01
The answer that held for years
Sunscreen absorbs the same wavelengths your skin uses to make vitamin D, so in theory it should reduce production. In practice, review after review of real-world use found little measurable effect, and the standard advice became that worrying about vitamin D was not a reason to skip sun protection.[2]
The usual explanation was under-application. People apply a fraction of the tested amount, miss areas, and spend time outdoors before applying anything. A sunscreen used the way people actually use it lets plenty of ultraviolet light through.[2][5]
An older randomized trial in Australia supported that reassurance. It was a reasonable position on the evidence available.[3]
Section 02
What changed
A trial published in 2025 randomly assigned Australian adults who were not already regular sunscreen users, and not taking supplements, either to apply SPF 50 or higher routinely on high ultraviolet days or to use sunscreen at their own discretion, for about a year.[1]
The routine group ended with lower average blood levels of vitamin D and a higher risk of being deficient. The effect held among people who did not take supplements during the study.[1]
That is a stronger design than most of the earlier evidence, and it points the other way. The reasonable conclusion is that diligent, high-SPF daily use does reduce vitamin D, even though casual use appears not to.[1][2]
Section 03
What this does not mean
It is not an argument for less sun protection, and it will be used as one. The trade is between a nutrient you can replace for a few pence a day and ultraviolet damage that accumulates permanently.[4][1]
Deliberate unprotected sun exposure to raise vitamin D is the worst available option, because the exposure that makes vitamin D is the same exposure that damages DNA. There is no dose that gives you one without the other.[4]
Section 04
Who should actually pay attention
The people most likely to be affected are those who genuinely apply sunscreen properly every day, cover up as well, spend little time outdoors, or have deeper skin tones, which already reduce vitamin D production for a given amount of light.[1][4]
If you apply a thin layer to your face only on days you remember, this trial probably does not describe you, and the older reassurance still fits.[2][5]
Section 05
How to hold both findings
The two bodies of evidence are not in conflict once you notice they studied different behaviour. Casual use lets enough light through to matter little. Diligent high-SPF use does not.[2][1]
That is a good outcome for anyone who has been told a firm answer and then heard it contradicted. The answer did not flip; the question got more precise.[1][2]
Your next step
Turn this into a practical plan
Choose the guide that best matches what you see. Each one starts with what to try, how long to wait and when to get help.