Mineral water is sourced naturally and is distinguished by its consistent composition of dissolved minerals and trace elements. Lithium occurs naturally in the Earth’s crust and subsequently dissolves into groundwater sources. The concentration of lithium in mineral water is a function of the local geology, which is why some springs contain significantly higher levels of this trace element than others.
Identifying the Highest Lithium Sources
The highest concentrations of naturally occurring lithium in bottled mineral water are found in specialized “lithia” waters from geologically unique regions. These waters often contain levels significantly greater than standard bottled or tap water. One of the highest reported concentrations is from the Armenian water, Hankavan-Lithia, documented to contain up to 5,450 micrograms per liter (\(\mu\text{g/L}\)), or 5.45 milligrams per liter (\(\text{mg/L}\)).
Another significant source is the Portuguese water, Vidago, which contains concentrations exceeding 1,500 \(\mu\text{g/L}\), with specific analyses reporting up to 2,220 \(\mu\text{g/L}\). Other international examples include Vichy Catalan from Spain (approximately 1,300 \(\mu\text{g/L}\)) and China’s 5100 Tibet Spring (around 250 \(\mu\text{g/L}\)). In the United States, Lithia Spring Water from Georgia is a commercial example, advertising a lithium content of about 500 \(\mu\text{g/L}\).
These high-content waters stand out compared to more widely available brands, such as San Pellegrino, which contains 120 \(\mu\text{g/L}\). The specific geographical source and underlying rock formations are the primary determinants of these exceptionally high concentrations.
Natural Variation in Lithium Concentrations
The concentration of lithium in groundwater is directly influenced by the interaction between water and the surrounding geological environment over long periods. Lithium is leached from certain rock types, such as granite, volcanic ash, and clastic materials. Water that remains in contact with these lithium-bearing minerals for extended times or at elevated temperatures tends to dissolve more of the element.
Higher lithium levels are observed in groundwater from arid regions or older aquifers, where processes like extensive evaporation can concentrate the dissolved minerals. The mixing of deep geothermal waters or brines with shallower water sources also contributes to elevated lithium content. The natural range of concentrations is immense, spanning from less than 1 \(\mu\text{g/L}\) in some public water supplies to thousands of micrograms per liter in specialized mineral springs.
For context, a comprehensive study of groundwater in the United States found that lithium concentrations in public-supply wells ranged from less than 1 \(\mu\text{g/L}\) up to 396 \(\mu\text{g/L}\), with a median value of 8.1 \(\mu\text{g/L}\). A survey of Hungarian bottled mineral waters showed a range from 4.2 \(\mu\text{g/L}\) to 209 \(\mu\text{g/L}\), illustrating how concentrations vary significantly even without considering specialized “lithia” products.
Lithium Intake from Water vs. Dietary Context
While certain mineral waters contain high lithium concentrations, the majority of an individual’s daily intake is obtained through the food we eat. Daily lithium intake for an adult in the United States ranges from approximately 650 to 3,100 \(\mu\text{g}\).
Primary dietary sources include grains, vegetables, nuts, and legumes, contributing between 66% and over 90% of a person’s total lithium intake. The lithium content in these foods is highly dependent on the concentration of the element in the soil where they are grown. Overall lithium consumption is a cumulative result of regional soil composition, diet, and drinking water source.
A person consuming a quarter liter (250 \(\text{mL}\)) of a very high-lithium water, such as Vidago at 2,220 \(\mu\text{g/L}\), would ingest about 555 \(\mu\text{g}\) of lithium. This is a substantial amount, but it falls within the total daily intake range and does not approach pharmacological levels. The concentrations found in the highest mineral waters are trace amounts, being thousands of times lower than therapeutic doses prescribed for mental health conditions.
The presence of lithium in drinking water is not regulated as a therapeutic substance by health agencies. The U.S. Environmental Protection Agency (EPA) has proposed a non-enforceable Health-Based Screening Level of 10 \(\mu\text{g/L}\) for lithium in drinking water. This regulatory approach emphasizes that the element, even at higher natural levels, is viewed as a naturally occurring trace element rather than a medication.