Well, there are those opponents to fluoride who say that it is a gas that inhibits the formation of antibodies in the blood, which causes a disruptive effect on various tissues in the body, which then confuses the immune system and causes it to attack its own tissues(exactly what lupus does!). Fluorine is a gas (many opponents say that it is a poisonous gas), as are the related elements chlorine and bromin. Fluoride is probably not essential to humans, although it is helpful in strengthening the bones and teeth and that is why it is added to our water supply. It is found only in trace amounts, about 2-3 grams, in the body, and most of that is in bones and teeth. The blood level of fluoride is about 0.3 mg. per 100 ml. Fluoride has no known function other than strengthening teeth and bones. The right amount of fluoride is water supply is about 0.7 parts per million (ppm), which is enough to prevent cavities but not too much so as to cause obvious fluorosis (person has had too much fluoride. People with fluorosis have white spots or blotches on their teeth. These spots can stain or become dark). It is felt that over 20 ppm (parts per million), much damage can occur, including decreased growth and cellular changes, especially in the metabolically active organs such as the liver, kidneys, adrenal glands, and reproductive organs.
I guess this is another one of those issues that we need to educate ourselves about because many of our doctors do tell us to brush with fluoridated toothpastes. There are many websites on the pros and cons of fluoride, so we have to make our own educated decisions about it and insist that our doctors respect whatever decision we've made