Is fluoride neccesary?


Fluoride is found in water in many countries as an additive, but for those countries where it is not, do one get the required 4mg daily from brushing your teeth, breathing air, or eating oats for those of us who are going to base their soylent on oats?

Are there other sources for it? Black tea is one good source I found. Is it neccesary? Wiki and other sources writes that is neccesary for stomach acid production and teeth and bones. However, as a grown up, do we need to add it more than gets into our body by other means?


Here’s what I found about fluoride. The recommendation is 4mg/day (; though fluoride may not be essential. Generally, water fluoridation aims for 1mg fluoride per liter. There is a website that will tell you what level it’s at in your area if you live in the US: If you’re consuming 3.7 liters per day, then you’re getting 3.7 mg, which is about enough. If you also use fluoride toothpaste, then you’re probably covered. Also note, if you use filtered water, it probably still has fluoride in it since most filters (which use carbon filtration) don’t remove it; though there are special filters that do.

Concerning black tea, I don’t think the tea leaves themselves have fluoride. I think the listed fluoride comes from the fluoridated water used to cook them (not certain though. Here they say no: Same with oats (this site says there is no fluoride in oats: On the other hand, fluoride will generally be in any product you consume that was processed with fluoridated water, since the fluoride will be left behind after the water is removed. I don’t know which products those might be, but perhaps some of the things you’re taking.

All told, considering that the upper limit for fluoride is 10 mg, I don’t think you need to supplement with it.

Edit: I was wrong about the black tea. It’s got quite a bit of fluoride. How much appears to vary considerably.


Well as I am not from the US and Norway does not have fluor added to the water, this might be an issue for me, and for others in the same situation. is a good source of nutrition data, however, some of the micronutrients are not listed, or not listed on all foods, as is the case with fluoride. Black tea is supposed to have fluoride in it, based on a nutriontable I found that listed black tea “unprepeared”. Dont have the source of it right now. Ill check it up. Anyone have any numbers for toothpaste or trace amounts in other foodstuff?

edit: wikipedia…
edit2: suddenly seem to find alot of stuff… “Fresh water supplies generally contain between 0.01–0.3 ppm” - that amounts to aprox 0,12 mg for 4 liters of fresh water.


My toothpaste lists fluoride at 0.16%. If you use a gram of toothpaste per use, that’s 1.6 mg. You probably aren’t swallowing more than trace amounts of toothpaste, but fluoride’s beneficial effects seem to derive not from ingestion, but mostly from topical application ( So a fluoride mouth wash in addition to toothpaste might be enough.

You’re probably right about the black tea. I can’t find good information, but the amounts I see listed (600+ micrograms) seem higher than you would expect from just the fluoride in the water (a cup of water would only have approximately 237 micrograms fluoride).


Topical application only applies when considering the benefits of fluor on teeth. Bones and stomach acid however. Also, two concerns regarding stomach acid. As absorbability from foods are better than pills, high acidity in the stomach is needed to properly break down the supplements, or so it seems. In one article i read, not all of the vitamins/minerals are dissolved in water, thus more power is needed. Or so it seems to me. So a soylent diet with low fluoride contents would decrease the amount/acidity of your stomach acid, leading to lower absoroption rates, thus your not getting what you need.