The effect of sunscreen on vitamin D: a review.
Level 1 - systematic review of randomized trials
Systematic review including randomized controlled trials along with observational and experimental studies
PubMed 30945275 · doi:10.1111/bjd.17980
What was done
A systematic review was conducted following MOOSE guidelines searching English-language literature published between 1970 and November 21, 2017. Eligible designs included experimental studies using artificial ultraviolet radiation (UVR), field trials, and observational studies examining the association between sunscreen use and circulating vitamin D3 or 25-hydroxyvitamin D [25(OH)D] concentrations. Results were qualitatively synthesized, and study quality scoring criteria were applied by two authors to observational studies.
What was found
The review included 76 studies: 4 experimental studies, 3 field trials (including 2 randomized controlled trials), and 69 observational studies. In experimental studies, sunscreen application substantially abrogated vitamin D3 or 25(OH)D synthesis induced by artificial UVR. Randomized controlled field trials showed no effect of daily sunscreen application on 25(OH)D, though tested formulations provided only moderate protection (SPF ~16). Observational studies mostly found no association or reported that self-reported sunscreen use was associated with higher 25(OH)D concentrations. The abstract reported no pooled numerical effect estimates or confidence intervals.
Why it matters
This review provides evidence that real-world sunscreen use at moderate SPF levels does not compromise circulating vitamin D concentrations, indicating that photoprotection recommendations for skin cancer prevention do not inherently drive vitamin D deficiency.
Limits
No field trials evaluated modern high-SPF sunscreens that are currently standardly recommended. Observational studies relied largely on self-reported sunscreen use, introducing potential reporting bias and residual confounding from outdoor activity, while experimental studies used artificial UVR sources that do not replicate the spectral output of terrestrial sunlight.