Ultraviolet B radiation (UVB) (UVB)

Ultraviolet B (UVB) radiation consists of electromagnetic waves with wavelengths ranging from 280 to 315 nm (WHO, 2023). While not a biological molecule or receptor, it serves as a critical environmental stimulus and therapeutic modality that interacts with endogenous chromophores. Its primary physiological role is the cutaneous synthesis of Vitamin D3 from 7-dehydrocholesterol, which is essential for systemic calcium regulation (NIH, 2022). However, UVB is also a major environmental carcinogen; it is directly absorbed by DNA, causing the formation of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts, which can lead to mutations in the p53 tumor suppressor gene and subsequent skin cancer (PubMed, PMID: 25105050). In clinical medicine, controlled exposure to narrowband UVB is a standard treatment for inflammatory skin diseases like psoriasis and vitiligo, acting through the induction of T-lymphocyte apoptosis and the suppression of pro-inflammatory cytokines (StatPearls, 2023). Pharmacological interaction occurs primarily through sunscreens, which absorb or reflect UVB photons, and photosensitizing drugs that enhance the skin's sensitivity to radiation damage.

Other names

Ultraviolet B photonsUV-BMedium-wave ultraviolet radiation280-315 nm radiation

UVB photons are absorbed by endogenous chromophores; in DNA, this leads to the formation of cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (PubMed, PMID: 25105050). In the skin, UVB facilitates the photolysis of 7-dehydrocholesterol to pre-vitamin D3 (NIH, 2022). It also activates the Aryl hydrocarbon receptor (AhR) and induces the production of immunosuppressive cytokines like IL-10 (StatPearls, 2023).