Ohgami et al Reference Ohgami, Terao, Shiotsuki, Ishii and Iwata1 reported lithium in drinking water (0.7–59 gm/l) and linked it to suicide rates. However, dietary lithium, which has received scant attention, is found in grains and vegetables, and to some extent animal-derived foods. Reference Schrauzer2 Hence, considering only lithium in drinking water may not be enough of a link to suicide rates. Dietary sources of lithium may actually have made the difference rather than just the drinking water. Differences in the prevalence of mood disorders with natural lithium levels acting as a prophylactic have been reported. Reference Jathar, Pendharkar, Pandey, Raut, Doongaji and Bharucha3,Reference Doongaji, Jathar and Satoskar4 Jathar et al Reference Jathar, Pendharkar, Pandey, Raut, Doongaji and Bharucha3 assessed the lithium content of the daily diet (72.55–154.6 μg) and biological fluids, and hypothesised lithium to be a natural prophylactic. It will be interesting to see whether dietary and drinking water lithium levels have a direct impact on mood disorder prevalence, which in turn could explain the variation in suicide rates. And what about lithium-containing food cooked in lithium-containing tap water?