You're being misleading here. Your original comment heavily implied that nickel is essential for humans and stainless steel pans were an important source. Per

You're being misleading here. Your original comment heavily implied that nickel is essential for humans and stainless steel pans were an important source. Per your source, nickel-containing enzymes are present in "primitive eukaryotes". Not humans. There are no known human enzymes or cofactors that depend on nickel. Chromium, meanwhile, has been known to be an essential trace element in humans for many decades[0][1]. [0] https://pubmed.ncbi.nlm.nih.gov/2602941/ https://pubmed.ncbi.nlm.nih.gov/2602941/ [1] https://pdfs.semanticscholar.org/24a7/c6a0d26945a6063bdcd3f61503c900b64559.pdf https://pdfs.semanticscholar.org/24a7/c6a0d26945a6063bdcd3f6...