Complex sentence: As with any supplement, care must be taken during use; in at least one case "U. tomentosa" was implicated in causing kidney failure in a patient with Lupus erythematosus.
Split into simpler sentences: As with any supplement, care must be taken during use. Specifically, in at least one case "U. tomentosa" was implicated in causing kidney failure in a patient with Lupus erythematosus.