An RDA For Lithium? On The Order Of 1 mg/day?

The ridges form as the salt crystallises from the evaporating water following the rains each year. Salar de Uyuni (or Salar de Tunupa) is the world's largest salt flat at 10,582 km² (4,085 square miles)[1]. It is located in the Potosí and Oruro departments in southwest Bolivia, near the crest of the Andes, 3,650 meters high. The major minerals found in the salar are halite and gypsum. Some 40,000 years ago, the area was part of Lake Minchin, a giant prehistoric lake. When the lake dried, it left behind two modern lakes, Poopó Lake and Uru Uru Lake, and two major salt deserts, Salar de Coipasa and the larger Uyuni. Uyuni is roughly 25 times the size of the Bonneville Salt Flats in the United States. Salar de Uyuni is estimated to contain 10 billion tons of salt, of which less than 25,000 tons is extracted annually. All miners working in the Salar belong to Colchani's cooperative. They work from dawn to dusk and most of them do not take a lunch break in order to take advantage of time, getting energy by chewing coca leaves. Every November, Salar de Uyuni is also the breeding grounds for three species of South American flamingos: the Chilean, James's and Andean flamingos. It is also a significant tourist destination; highlights include a salt hotel and several so-called islands. http://en.wikipedia.org/wiki/Salar_de_Uyuni

Bolivia’s naturally-occurring salt flat, Salar de Uyuni, contains the world’s largest single deposit of lithium.

Well, this is interesting…
Lithium is an element, a metal. In the periodic table it’s in the same group/column as sodium and potassium. Lithium is not a molecule. It is not synthetic. It’s a naturally occurring substance, usually as a salt. There’s an argument that it should be considered an essential nutrient:

Lithium: Occurrence, Dietary Intakes, Nutritional Essentiality, Journal of the American College of Nutrition, February 2002

Lithium is found in variable amounts in foods; primary food sources are grains and vegetables; in some areas, the drinking water also provides significant amounts of the element. Human dietary lithium intakes depend on location and the type of foods consumed and vary over a wide range. Traces of lithium were detected in human organs and fetal tissues already in the late 19th century, leading to early suggestions as to possible specific functions in the organism. However, it took another century until evidence for the essentiality of lithium became available. In studies conducted from the 1970s to the 1990s, rats and goats maintained on low-lithium rations were shown to exhibit higher mortalities as well as reproductive and behavioral abnormalities. In humans defined lithium deficiency diseases have not been characterized, but low lithium intakes from water supplies were associated with increased rates of suicides, homicides and the arrest rates for drug use and other crimes. Lithium appears to play an especially important role during the early fetal development as evidenced by the high lithium contents of the embryo during the early gestational period. The biochemical mechanisms of action of lithium appear to be multifactorial and are intercorrelated with the functions of several enzymes, hormones and vitamins, as well as with growth and transforming factors. The available experimental evidence now appears to be sufficient to accept lithium as essential; a provisional RDA for a 70 kg adult of 1,000 microg/day is suggested.

That’s 1 mg/day. That’s not much, but in my reading it does seem to be doing something at this low dose. This is nowhere near the amount used therapeutically, for example, to treat bipolar disease, which uses 900-2400 mg. This is a trace.

Is Lithium Potentially A Trace Element?, World Journal of Psychiatry, March 2015

The average daily lithium intake of an American 70 kg/154 lb adult has been estimated at between 0.6 mg to 3.1 mg, so 1 mg would fall within a range that a healthy diet provides. Foods with the highest amounts of lithium come from plants – grains and vegetables have 0.5-3.4 mg/kg of lithium. Dairy food (0.5 mg/kg) and meat (0.012 mg/kg) have smaller amounts, depending on the foods the animals eat. Lithium in the plant is dependent upon lithium in the soil and water, and upon the tendency of the plant to take it up. Tomatoes, peppers, eggplant and other members of the nightshade family do that well.

This article by Harvard-trained Dr. Anna Fels, a psychiatrist, author, and faculty member at Weill Cornell Medical School last year got a lot of attention:

Should We All Take a Bit of Lithium?, New York Times, 13 September 2014

She’s arguing for that micro-dose of 1 mg/day (even though she treats with amounts several hundred times that):

Evidence is slowly accumulating that relatively tiny doses of lithium can have beneficial effects. They appear to decrease suicide rates significantly and may even promote brain health and improve mood.

[She describes various supportive studies.]

Trying to make sense of their results, the authors of the Japanese study speculated that lithium exposure, even in these tiny amounts, might actually be neuroprotective or even enhance the growth of neurons. Other studies have supported their speculation; lithium appears to promote the health, growth and resilience of neurons, reducing stress-induced damage.

Dr. Nassir Ghaemi, a professor of psychiatry at Tufts University School of Medicine and one of the most active and informed proponents of lithium in the medical community, notes: “Lithium is, by far, the most proven drug to keep neurons alive, in animals and in humans, consistently and with many replicated studies.” And, he added, “If lithium prevents dementia, then we may have overlooked a very simple means of preventing a major public health problem.”

Some scientists have, in fact, proposed that lithium be recognized as an essential trace element nutrient.

Why hasn’t lithium gotten more attention?

But there are undoubtedly other reasons for its neglect. Pharmaceutical companies have nothing to gain from this cheap, ubiquitous element.

She ends:

For the public health issue of suicide prevention alone, it seems imperative that such studies be conducted. In 2011, suicide was the 10th leading cause of death in the United States. Research on a simple element like lithium that has been around as a medication for over half a century and as a drink for millenniums may not seem like a high priority, but it should be.

Let me ask you … if you were a large pharmaceutical company that made a lot of money selling drugs for depression and other mental health issues, and you had a lot of influence in the research that universities and government conducted, would you steer them away from investigating the effects of a simple, cheap, naturally-occurring salt that had the potential of undercutting your profits?

Another study:
Low-dose Lithium Uptake Promotes Longevity In Humans And Metazoans, European Journal of Nutrition, August 2011

Lastly and given the long-standing psychiatric experience with high-dose Li+ supplementation in humans, these findings raise the possibility that readily available low-dose Li+ supplementation at non-toxic doses may not only promote mental health and impair suicide risk [2, 7, 8] but also may reduce overall mortality in humans.

Some mineral waters list their lithium content. It looks like you could get about a tenth of that proposed 1 mg/day by drinking a liter of one of these: