Does Sunscreen Block Vitamin D? What the Research Shows
Lab studies show sunscreen can reduce vitamin D production, but real-world trials and reviews find little effect. What that means for your skin and your vitamin D.
In theory sunscreen can reduce vitamin D production, but in real life it doesn't seem to cause vitamin D deficiency. The short answer: lab experiments with artificial UV show sunscreen blocks much of the vitamin D response, yet field trials and observational studies have mostly found no drop in blood vitamin D levels among regular sunscreen users.
What the evidence shows
A 2019 systematic review in the British Journal of Dermatology looked at 4 lab experiments, 3 field trials (2 randomized) and 69 observational studies (Neale et al., Br J Dermatol, 2019):
| Type of study | Finding |
|---|---|
| Lab experiments with artificial UV | Sunscreen substantially reduced vitamin D production |
| Randomized field trials | No effect from daily sunscreen use, but the sunscreens had moderate protection, around SPF 16 |
| Observational studies | Mostly no association, or sunscreen users had higher vitamin D levels |
The authors concluded there's little evidence that sunscreen lowers vitamin D in real-life use, and that vitamin D concerns shouldn't override skin cancer prevention advice. They also noted that no trials have tested the high-SPF sunscreens now widely recommended.
A key randomized trial
In an Australian trial, 113 adults aged 40 and over were randomly assigned to daily SPF 17 sunscreen or a placebo cream over a summer. Blood levels of 25-hydroxyvitamin D rose by about the same amount in both groups, and nobody, including people 70 and over, ended up with vitamin D outside the normal range (Marks et al., Arch Dermatol, 1995).
Why sunscreen doesn't block it completely
The authors of the Australian trial suggested people still got enough sunlight for vitamin D, probably through the sunscreen itself and because skin is rarely covered completely at all times (Marks et al., Arch Dermatol, 1995). The 2019 review also points out that lab experiments use artificial UV with a different spectrum from real sunlight (Neale et al., Br J Dermatol, 2019).
If you're worried about your vitamin D
Ask your doctor whether a blood test makes sense for you, especially if you rarely go outside or have a medical condition that affects nutrient absorption. Food and supplements are ways to get vitamin D without adding UV damage to your skin.
Sunscreen and aging
Skipping sunscreen to make vitamin D trades a small, uncertain benefit for well-documented harm. Daily sunscreen slowed visible skin aging in a 4.5-year randomized trial (Hughes et al., Ann Intern Med, 2013). The AAD recommends broad-spectrum SPF 30 or higher (AAD: sunscreen FAQs).
Frequently asked questions
Should I skip sunscreen for 15 minutes a day to get vitamin D? Not as a rule. Discuss vitamin D with your doctor; supplements avoid UV damage.
Does SPF 50 block more vitamin D than SPF 15? In theory it could; real-world trials of high-SPF sunscreens are lacking.
This article is for educational purposes only and is not medical advice. Talk to a board-certified dermatologist about your situation.
Sources
- Neale RE et al. The effect of sunscreen on vitamin D: a review. Br J Dermatol. 2019. PubMed
- Marks R et al. The effect of regular sunscreen use on vitamin D levels in an Australian population: a randomized controlled trial. Arch Dermatol. 1995. PubMed
- Hughes MC et al. Sunscreen and prevention of skin aging: a randomized trial. Ann Intern Med. 2013. PubMed
- American Academy of Dermatology. Sunscreen FAQs
