Lithium is an essential micro-nutrient with some chemical properties similar to calcium and magnesium. It is present in all organs and tissues in the body. Lithium has a long history of clinical use for supporting healthy mood and behavior. Mechanisms for this involve promoting dopamine and serotonin neurotransmitter activity. Lithium also plays a role in gene expression of natural detoxification enzymes in the brain, including glutathione-s-transferase (GST). This offers important neuron antioxidant protection, which may also contribute to healthy spatial memory. Lithium may support healthy brain receptor function and brain signaling cascades to maintain healthy mental function.

Hair lithium has been shown to be a good indicator of dietary lithium intake. Because a major source of dietary lithium can come from municipal water supplies, the increase in drinking purified water may be a cause of deficiency.