was ist k3 — what are common causes?

The term 'K3' is not defined in the provided context. It could refer to vitamin K3 (menadione) or keratin 3, but no evidence is available. If the question relates to skin aging (group '13_haut_beauty'), the data show that genetic variants in COL1A1 (e.g., rs1800012 and rs4746) can influence collagen structure. Allele frequencies vary widely across populations (e.g., A-allele in Europeans ~19%). However, the predictive power of such single SNPs is low and overshadowed by lifestyle factors (UV exposure, diet, smoking). Clinical tests based solely on these markers lack established diagnostic utility. Without a clear definition of 'K3', the answer remains speculative. Evidence: unclear because the term is not present in the knowledge context.