Passage: Niobium has no known biological role. While niobium dust is an eye and skin irritant and a potential fire hazard, elemental niobium on a larger scale is physiologically inert (and thus hypoallergenic) and harmless. It is frequently used in jewelry and has been tested for use in some medical implants.Niobium-containing compounds are rarely encountered by most people, but some are toxic and should be treated with care. The short- and long-term exposure to niobates and niobium chloride, two chemicals that are water-soluble, have been tested in rats. Rats treated with a single injection of niobium pentachloride or niobates show a median lethal dose (LD50) between 10 and 100 mg/kg. For oral administration the toxicity is lower; a study with rats yielded a LD50 after seven days of 940 mg/kg.

Question: Does Niobuim serve any biological purpose?
no known biological role