Lithium: Perspectives of nutritional beneficence, dietary intake, biogeochemistry, and biofortification of vegetables and mushrooms

Highlights: • Low dietary intake of lithium is associated with many psycho-behavioral disorders. • Lithium intake is insufficient in many countries of the world. • Lithium is highly plant available and shows growth promoting effect at lower levels. • Vegetables and mushrooms can be Li-biofortified without compromising quality/yield. • Future research should focus on Li biofortification of cereals. Although lithium (Li) is not an essential nutrient for humans, low Li intakes are associated with increased suicide and homicide rates, aggressive behaviors, unipolar/bipolar disorders, acute mania, etc. On the other hand, Li is one of the most effective psychopharmacological agents used for the treatment of these psycho-behavioral disorders. The beneficial normothymic effect of Li could be achieved at lower doses, therefore, modern psychiatry has called to consider Li biofortification of foods to improve its dietary intake. The concept of agronomic biofortification of crops with Li is juvenile and there exist a limited number of studies, mainly focused on vegetables or mushrooms. This review, first of its kind, discusses the nutritional beneficence and dietary intake of Li, its biogeochemistry, and opportunities and challenges in the Li biofortification of food crops. Literature showed that dietary intake of Li in many countries of the world is insufficient, compared to the provisional recommended dietary allowance (RDA) of 1.0 mg day⁻¹ for a 70 kg adult. Lithium contents of soils are widely variable and the metal has high mobility in soils, making it more prone to leaching, and available for plant uptake. Biofortification studies reveal that plants can accumulate significant quantities of Li in their edible tissues without yield loss and quality associated negative effects. At lower application rates, Li tissue concentration could reach to the level that consuming 100–200 g of Li-biofortified fresh vegetables or mushrooms could support its RDA. It seems impossible to enrich the plants with Li to the levels that allow their application in psychiatric treatments, which requires the dosage of 600–1200 mg day⁻¹. However, there is need to refine the methods of Li biofortification strategies to obtains plant specific concentration of Li in edible parts so that consuming a specific amount could provide the proposed dietary intake requirement.