Because lithium is abundantly present in rocks and soils, the mineral is also found in significant amounts in our food and water supplies. The U.S. Environmental Protection Agency has estimated that the daily lithium intake of an average adult ranges from about 0.65 mg to 3 mg. Grains and vegetables serve as the primary sources of lithium in a standard diet, with animal byproducts like egg and milk providing the rest. Lithium has even been officially added to the World Health Organization’s list of possible nutritionally essential trace elements, in a report covering zinc, iodine and others. 

The most frequent source of lithium in the modern diet however is tap water. Depending on geographical location, drinking water can be quite potent in naturally occurring lithium. According to environmental surveys, water with high mineral content content can translate to 2 mg or so of lithium per day. A series of fascinating ecological studies has found that communities with higher levels of lithium in the water,have lower overall rates of psychiatric illness, suicide and violent crime. 1

Due to the lack of attention attributed to lithium as a food source by the FDA and other dietetic associations, there is little research on the specific consequences of lithium deficiency in humans. However, trials in which animals have been put on low lithium diets have revealed a gross decrease in reproductive function, life span and lipid metabolism as a result.  It is quite possible that the effects of lithium deficiency amidst humans are widespread, yet under-recognized as such and mistaken for other medical phenomena. 2