==Special Precautions of Nickel==
* Toxicity is the main concern here-not from elemental nickel or the nickel found in foods but from inhaled nickel carbonyl, a carcinogenic gas that results from the reaction of nickel with heated carbon monoxide, from cigarette smoke, car exhaust, and some industrial wastes. Nickel carbonyl is toxic and can cause symptoms such as frontal headaches, nausea, vomiting, or vertigo with acute exposure. Inhaled nickel accumulates in the lungs and has been associated with increased rates of lung, nasal, and laryngeal cancers.
*Nickel allergy can also cause local skin or systemic reactions. The nickel in jewelry, dental materials, or prosthetic joints or heart valves may also be allergenic sources.
==The benefits of Nickel are==
* The biological function of nickel is still somewhat unclear. Nickel is found in the body in highest concentrations in the nucleic acids, particularly RNA, and is thought to be somehow involved in protein structure or function. It may activate certain enzymes related to the breakdown or utilization of glucose. Nickel may aid in prolactin production, and thus be involved in human breast milk production. Nickel enables dietary iron absorption and contributes to the development of red blood cells.