Claim Verification: "Sunscreen is more dangerous due to chemical absorption and vitamin D blocking than moderate sun exposure." — Disproved

Automated fact-verification of the claim: "Sunscreen is more dangerous due to chemical absorption and vitamin D blocking than moderate sun exposure." Verdict: DISPROVED Key Findings Chemical absorption is real but not proven harmful. FDA-sponsored JAMA studies (2019, 2020) confirmed that oxybenzone reaches up to 258 ng/mL in the bloodstream and persists for 21 days — yet both studies' authors explicitly concluded "these findings do not indicate that individuals should refrain from the use of sunscreen." The American Academy of Dermatology (AAD) states that absorption into the bloodstream "does not mean that it is harmful or unsafe" (B1). Sunscreen does not limit vitamin D in real-world use. A 2022 international expert panel (PMC) found that outdoor population studies showed vitamin D levels "did not seem to differ between those applying sunscreen and those who did not, with exposure time and body surface area exposed being equivalent" (B4). UV radiation is the dominant cause of skin cancer. About 90% of nonmelanoma skin cancers and approximately 86% of melanomas are attributed to UV exposure (B5). Sunscreen use reduces melanoma risk by ~50% and squamous cell carcinoma by ~40%, supported by high-quality randomized controlled trials (B3). 5 of 5 independent authoritative sources reject the claim (threshold: 3). No peer-reviewed study was found concluding that sunscreen causes greater net harm than moderate unprotected sun exposure. > Note: 3 of 5 citations (B1, B2, B5) come from domains classified as unclassified by the automated credibility system (tier 2). These institutions — the American Academy of Dermatology, MD Anderson Cancer Center, and the Skin Cancer Foundation — are among the most authoritative in dermatology and oncology. See Source Credibility Assessment in the audit trail. Files proof.py — Re-runnable Python verification script proof.md — Structured proof report proof_audit.md — Full verification audit trail proof_narrative.md — Plain-language summary proof.json — Machine-readable structured data Generated by Proof Engine v1.3.1.