Some water suppliers (usually municipalities) fluoridate their water, and publish the final fluoride content of their water. In many desi city waters, there is natural fluoride (of varying unknown amounts), and the population of the young people never suffer from cavities (comes from not enough of it) or fluorosis (comes from too much of it). One medical article goes: Exposure to high concentrations of fluoride during childhood, when teeth are developing, can result in mild dental fluorosis. There will be tiny white streaks or specks in the enamel of the tooth. This does not affect the health of the teeth, but the discoloration may be noticeable. Breastfeeding infants or making up formula milk with fluoride-free water can help protect small children from fluorosis. Children below the age of 6 years should not use a mouthwash that contains fluoride. Children should be supervised when brushing their teeth to ensure they do not swallow toothpaste. Skeletal fluorosis Excess exposure to fluoride can lead to a bone diseaseTrusted Source known as skeletal fluorosis. Over many years, this can result in pain and damage to bones and joints. The bones may become hardened and less elastic, increasing the risk of fractures. If the bones thicken and bone tissue accumulates, this can contribute to impaired joint mobility. Thyroid problems In some cases, excess fluoride can damage the parathyroid gland. This can result in hyperparathyroidism, which involves uncontrolled secretion of parathyroid hormones. This can result in a depletion of calcium in bone structures and higher-than-normal concentrations of calcium in the blood. Lower calcium concentrations in bones make them more susceptible to fractures. Neurological problems In 2017, a report was published suggesting that exposure to fluoride before birth could lead to poorer cognitive outcomes in the future. The researchers measured fluoride levels in 299 women during pregnancy and in their children between the ages of 6 and 12 years. They tested cognitive ability at the ages of 4 years and between 6 and 12 years. Higher levels of fluoride were associated with lower scores on IQ tests. In 2014, fluoride was documented as a neurotoxin that could be hazardous to child development, along with 10 other industrial chemicals, including lead, arsenic, toluene, and methylmercury. While all of that is on the one side, there is this on the other: https://healingthebody.ca/tamarind-...MEWMpYflNxS2PyUJTG67AyEsjIQf9qm72mW9J5NKsNQJs There are some restaurants in South India that serve "bottomless sambar" with their tiffin items. Does this contribute to good bone health ?