Evidence Based

Skeletal Fluorosis: Symptoms, Causes & Prevention

What Is Skeletal Fluorosis?

Skeletal Fluorosis is a chronic bone and joint disease caused by long term consumption of fluoride.

As fluoride accumulates in the bones it begins to negatively alter processes of bone formation and resorption- affecting the entire skeleton.1

Gradually bones become weaker and more brittle, while joints increase in pain and stiffness due to skeletal changes.

On-going fluoride exposure can lead to “crippling skeletal fluorosis” the most severe case of the disease. A result of calcification of ligaments, immobility, muscle wasting, and neurological problems related to spinal cord compression.2

picture of x-ray's of fractured bones

Thankfully, skeletal fluorosis is a preventable crippling disease.

However, as it stands, there are no treatments capable of curing skeletal fluorosis.

What makes things more complicated is through its gradual development it can be difficult to distinguish from a number of other bone and joint diseases.

Making it hard to detect without knowing what to look for.

What Are The Symptoms Of Skeletal Fluorosis?

Skeletal fluorosis symptoms

Generally, the larger and greater the exposure to fluoride- the more severe the symptoms.2

While the earlier fluoride exposure is stopped, the better chance of reversing the effects, or even better- avoiding them entirely.

The most common early symptoms of skeletal fluorosis are:

  • Lower back pain3
  • Stiffness and pain in joints4
  • Weaker bones4
  • Growth lines on bone5

These early symptoms act as red flags.

When skeletal fluorosis progresses, much more serious health effects kick in.

Other Signs Of Skeletal Fluorosis?

Now since fluoride causes dental, skeletal and non-skeletal effects throughout the body, a person can use this to their advantage.6,7

Individuals that don’t experience the above symptoms, can spot the development of skeletal fluorosis by observing earlier health effects caused by fluoride:

Causes Of Skeletal Fluorosis?

icons of factors that cause skeletal fluorosis, water, well-water, dental products and tea

The total amount of ingested fluoride is the leading factor which determines the development and progression of skeletal fluorosis.8

With fluoride being a cumulative toxin, the more you ingest, the more accumulates in your body.

In addition, fluoride exposure from any source or the combination of- can lead to skeletal fluorosis. With the largest and most consistent source of fluoride in most societies being fluoridated water, dental products, and fluoride in tea.9

Nonetheless, other sources of fluoride that will contribute to the risk of developing skeletal fluorosis:

Not to mention, other rare but equally detrimental sources like fluoride in well water, industrial fluoride exposure and indoor coal burning.10-12

What Does Fluoride Do In The Body?

When fluoride is ingested, it is absorbed into the blood through the digestive tract. 

With approximately 50% of fluoride being removed through urinary excretion, the rest is free to roam and accumulate in the body.4

Now when fluoride gets into the blood, uptake by bone removes it from circulation.13

This is due to fluoride’s negatively charged nature that allows it to react with positively charged ions like calcium. Thus collecting in high calcium areas, such as the bones and teeth.


When fluoride reacts with calcium in your bones, it forms calcium fluoride (CaF2).

Through this process, fluoride takes the place of naturally occurring calcium hydroxyapatite in the bone- altering normal bone formation and resorption.1

Leading to weaker and more brittle bones. 

When the body can not participate in naturally occurring bone formation and resorption, it leads to several different bone turnover disorders:

  • Osteomalacia (softening of the bone through inadequate bone mineralization)
  • Osteoporosis (body makes too little bone and/or loses to much bone, leaving bones weak and easy to break)
  • Osteoarthritis (most common form of arthritis, commonly affecting hands, knees, hips and spine)
normal bone vs bone with osteoporosis

Interestingly enough, radiologic findings suggest that fluoride’s primary effect is to stimulate bone formation.14

However, bone made during the development of skeletal fluorosis is not of good quality compared to bone made in healthy conditions. Mainly due to the abnormal bone formation that results in increased density but decreased strength.15

Leaving those with skeletal fluorosis at an increased risk of fracture.16

What Are The Stages Of Skeletal Fluorosis?

Due to skeletal fluorosis’s complexity, an individual’s progression through its stages may vary.

As fluoride bone concentrations do not always represent the symptoms an individual experiences.

For example, in the “pre-skeletal” stage, increased bone mass may not be observed but an individual may experience symptoms typically associated with stage 3, such as stiffness, backache or arthritis (spine, hands and fingers).

While someone else in the pre-skeletal phase may be symptom-free.

With that being said, the chart below provides a general guideline on how skeletal fluorosis develops in regard to bone fluoride concentrations.

Skeletal Fluorosis StagesFluoride Concentration (mgF/kg)Symptoms and Signs
Pre-Skeletal<3500Symptoms can start at this phase, without an increase in bone mass (arthritis of spine, hands and fingers)
Pre-Clinical Stage3,500 to 5000Increase in bone mass, generally no symptoms but stages 1 and 2 symptoms may start to emerge.
Stage 16,000 to 7000Infrequent pain, stiffness of joints, osteosclerosis of pelvis and vertebral column.
Stage 27,500 to 9,000Chronic joint pain, arthritis symptoms, sight calcification of ligaments, and osteosclerosis of cancellous bones.
Stage 38,400Crippling skeletal fluorosis; mobility is significantly affected due to excessive calcification in joints, ligaments and vertebral bodies.

How Is Skeletal Fluorosis Diagnosed?

Diagnosis of skeletal fluorosis is tricky.

As many doctors fail to detect it due to the symptoms of skeletal fluorosis appearing similar to other more well known, bone and joint diseases.

For example, when bone change occurs during skeletal fluorosis, it closely imitates other diseases like osteoarthritis, renal osteodystrophy, spondylosis, DISH, Paget’s Disease and osteopetrosis.11

Unfortunately this leaves many individuals undiagnosed until the advanced stage of crippling fluorosis.

Where it becomes impossible to cure.

For instance, in 2011 a group of U.S scientists reported a women with crippling skeletal fluorosis, as evident by her severe hunchback (“kyphosis”), had to wait up to 18 years before doctors were able to diagnose her condition as being caused by fluoride.11

effects of skeletal fluorosis osteoporosis effects on spongy bone

To further complicate matters, within the initial stages, a patient may suffer symptoms of skeletal fluorosis (joint pain, joint stiffness and gastric distress) without any detectable bone changes.17

As illustrated below, fluoride can be deposited underneath the skin and around the joints or the hand (left).

Going generally unnoticed until it progresses to obvious visual signs (right).

skeletal fluorosis osteoarthritis effect, inside and outside look

With diagnosis hard to pinpoint, the most likely diagnosis will be of conditions such as arthritis.

Followed by the prescription of drugs- leaving the patient without a real solution to what caused their symptoms (fluoride).

With the issue unattended to, more serious stages of skeletal fluorosis are likely to develop.

A situation that could be easily avoided if more doctors and individuals took into account an individual’s lifetime exposure to fluoride. 

Now, here is a general guideline to gauging how much fluoride has accumulated in one’s bodies.

According to the NRC, in the absence of other sources of fluoride, the consumption of drinking water with a fluoride level of 1 ppm, fluoride bone concentration can reach 2500 mg/kg in twelve years and to 3000 to 4000 mg/kg over longer periods.2

bone fluoride levels with the consumption of fluoridated water only- with stages of skeletal fluorosis

Now considering the US Environmental Protection Agency (EPA) has set a maximum amount of fluoride allowable in drinking water at 4.0 ppm.18

It’s clear that one who would like to avoid skeletal fluorosis should steer clear of public tap water.

Those At Higher Risk?

As mentioned in, what is fluoride, the seriousness of health effects caused by fluoride toxicity depend on the following several factors: age, calcium intake, kidney function, sex, dose and duration of fluoride intake.19

For example, if a male and female with all other factors equal were exposed to the same amount of fluoride, the female would experience more severe symptoms.

As on average, females have less bone mass, leaving the same amount of fluoride less bone to damage.

This is in part why, more females suffer from osteoporosis in their later years of life than males.

In fact, of the millions of Americans with osteoporosis, 80% are female.20

Warning: Young and developing children are of greatest risk to fluoride’s toxicity, making a fluoride-free environment critical to healthy development in early years.

On top of personal risk factors, the following lifestyle factors also play a role:

  • Heavy tea drinkers. 
  • Those with kidney impairments. 
  • Fluoridated water drinkers. 
  • Jobs exposing individuals to fluoride gas.

How Much Fluoride Is Safe?

question mark icon with glasses of water behind

The problem with current knowledge across North America is the belief that skeletal fluorosis does not occur at water fluoride levels below 4 ppm.

However, through extensive studies performed in India and China, it has been documented that skeletal fluorosis can occur at levels as low as 0.7 to 1.5 ppm of fluoride.21,22,23

This in part builds upon the previous section, as one amount of fluoride can have different effects in different people.

All of which points to individual susceptibility to fluoride:

  • Individuals who receive the same dose of fluoride can experience completely different health effect24
  • Individuals with pre-skeletal fluorosis can experience painful symptoms, while others with advanced skeletal fluorosis can remain symptom free25
  • It’s not always a gradual development to the point of fluorosis, it can happen in as little as 6 months in young children and be as fast as 2 to 7 years in adults26,27,28

Considering fluoride serves no essential function in human growth or development, along with being a toxin that accumulates throughout the body.

It’s safe to state, 0 fluoride is a safe amount of fluoride.

How Do You Treat Skeletal Fluorosis?

possible progression of skeletal fluorosis treatment

Current available treatments are unable to cure skeletal fluorosis.

The longer an individual is exposed to fluoride, the more it accumulates in their body and the harder it is to reverse the effects.

However, recent studies have shed some hope on skeletal fluorosis treatment:

  • Vitamin E and Methionine: can reduce the effects of fluoride on soft tissues and prevent excessive accumulation of fluoride in the bone.29
  • Choline: reduces damage to the chondrocyte matrix and degradation enzymes in mice treated with fluoride.30
  • Taurine: enhances thyroid gland function and renal antioxidant status in rats, reusing in restoration of fluoride-induced renal toxicity.31
  • Acupuncture: helps improve range of motion, relieve pain and stimulate urinary fluoride.32

Now as mentioned current therapies only act to control the health effects of skeletal fluorosis but can not cure it.

It can be reversible in some cases but this is purely dependent on how much the disease has progressed. 

With the process of reversing skeletal fluorosis is also the same way to prevent it.

How To Prevent Skeletal Fluorosis?

unbalanced scale with cure and prevention

An ounce of prevention is worth a pound of cure. 

Now there are two general steps to prevent skeletal fluorosis.

The first and most important step is to eliminate the substance that causes skeletal fluorosis, fluoride.

Since fluoride in drinking water is the largest source of fluoride, using a fluoride filter for your drinking water or drinking bottled water without fluoride should be of most importance.

Second, you’ll have to remove all the fluoride that has accumulated in your body.

When fluoride intake is stopped, the amount of fluoride in bone will decrease and be excreted via urine- however, this tends to be a very slow process.

To speed up this process, our fluoride detox guide outlines the most up-to-date methods to detox your body of fluoride. Along with every fluoride source you’re currently exposed to and how to get rid of it.

Final Words

one yellow fish among black fish swimming in opposite direction

What we put into our bodies should help us avoid illness, not bring us closer to it.

Considering how easy it is to avoid the health effects of fluoride, it’s quite unfortunate that millions of people have to suffer from it’s toxic nature.

But you have to be like the yellow fish in the photo above and swim in the opposite direction.

Lastly, fluoride and all its health effects, is essentially a war between good and bad guys.

With each glass of water with fluoride, use of fluoride-containing toothpaste or cup of coffee made with fluoridated water – “ammunition” is sent to the bad guys, while stripping away resources from the good guys.

The same way fluoride strips the body of calcium, leading to skeletal fluorosis.

Leading us to the most logical solution:

  • Stop sending ammunition to the bad guys (eliminate fluoride exposure)
  • Strip bad guys of the current ammunition they have (fluoride detox) 
  • Send resources to the good guys (drink better water)

Again, all steps are outlined in the fluoride detox guide.

A guide made after going through the entire process myself. Helping you do the same but avoiding all the mistakes, time wasted and money spent on poor products that did not help me live a healthier life.

Anyways, there you have it, the truth about fluoride in regards to skeletal fluorosis.


  1. Littleton, J. (1999), Paleopathology of skeletal fluorosis. Am. J. Phys. Anthropol., 109: 465-483.
  2. National Research Council . Review of Fluoride in Drinking Water, U.S. The National Academic Press; Washington, DC, USA: 2006.
  3. Namkaew M., Wiwatanadate P. Association of fluoride in water for consumption and chronic pain of body parts in residents of San Kamphaeng district, Chiang Mai, Thailand. Trop. Med. Inter Health. 2012;17:1171–1176. doi: 10.1111/j.1365-3156.2012.03061.x.
  4. Science Direct article: “Skeletal Fluorosis”
  5. Wang H, Tannukit S, Zhu D, Snead ML, Paine ML. (2005). Enamel matrix protein interactions. J Bone Miner Res 20:1032-1040
  6. Amalraj A., Pius A. Health risk from fluoride exposure of a population in selected areas of Tamil Nadu South India. Food Sci. Hum. Wellness. 2013;2:75–86. doi: 10.1016/j.fshw.2013.03.005.
  7. DenBesten P., Zhu L., Li W., Tanimoto K., Liu H., Witkowska H.E. Fluoride incorporation into apatite crystals delays amelogenin hydrolysis. Eur. J. Oral Sci. 2011;119:3–7. doi: 10.1111/j.1600-0722.2011.00903.x.
  8. https://www.ncbi.nlm.nih.gov/pubmed/3295994
  9. Fan Z, Gao Y, Wang W, et al. Prevalence of Brick Tea-Type Fluorosis in the Tibet Autonomous Region. J Epidemiol, 2016, 26:57–63.
  10. Truth ABout Fluoride: “Does Well Water Have Fluoride”
  11. Fluoride Alert: “Skeletal Fluorosis”
  12. Gao X, Hu Y, Li C, et al. Evaluation of fluorine release from air deposited coal spoil piles:A case study at Yangquan city, northern China.
  13. European Food Safety Authority Opinion of the Panel on Dietetic Products, Nutrition, and Allergies (NDA) on the tolerable upper intake level of fluoride. EFSA J. 2005;192:1–65.
  14. Savas S: “Endemic fluorosis in Turkish patients”
  15. Whitford GM (1994). “Intake and Metabolism of Fluoride”. Advances in Dental Research. 8 (1): 5–14.
  16. Teotia SP, Teotia M (March 1973). “Secondary hyperparathyroidism in patients with endemic skeletal fluorosis”. Br Med J. 1 (5854): 637–40.
  17. Czerwinski E: “Bone and joint pathology in fluoride-exposed workers”
  18. https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations
  19. Krishnamachari K.A. Skeletal fluorosis in humans: A review of recent progress in the understanding of the disease. Progr. Food Nutr. Sci. 1986;10:279–314.
  20. https://www.nof.org/preventing-fractures/general-facts/what-women-need-to-know/
  21. Gupta R, Kumar AN, Bandhu S, Gupta S. (2007) Skeletal fluorosis mimicking seronegative arthritis. Scandanavian Journal of Rheumatology 36(2):154-5.
  22. Ayoob S, Gupta AK. (2006). Fluoride in Drinking Water: A Review on the Status and Stress Effects. Critical Reviews in Environmental Science and Technology 36:433–487
  23. Bo Z, et al. (2003). Distribution and risk assessment of fluoride in drinking water in the west plain region of Jilin province, China. Environmental Geochemistry and Health 25: 421-31
  24. D. Chachra: “The Long-term Effects of Water Fluoridation on the Human Skeleton”
  25. Franke J, et al. (1975). Industrial fluorosis. Fluoride 8(2): 61-83. 
  26. Teotia M, et al. (1998). Endemic chronic fluoride toxicity and dietary calcium deficiency interaction syndromes of metabolic bone disease and deformities in India: year 2000. Indian J Pediatr. 65(3):371-81
  27. Fratzl, P., Roschger, P., Eschberger, J., Abendroth, B. and Klaushofer, K. (1994), Abnormal bone mineralization after fluoride treatment in osteoporosis: A small‐angle x‐ray‐scattering study. J Bone Miner Res, 9: 1541-1549
  28. Felsenfeld AJ, Roberts MA. (1991). A report of fluorosis in the United States secondary to drinking well water. Journal of the American Medical Association 265:486-8
  29. Błaszczyk I, Birkner E, GutowskaI. Influence of methionine and vitamin E on fluoride concentration in bones and teeth of rast exposed to sodium fluoride in dringing water. Biol Trace Elem Res, 2012, 146:335–9.
  30. Zhao Y, Hao J, Wang J, et al. Effect of Choline on the Composition and Degradation Enzyme of Extracellular Matrix of Mice Chondrocytes Exposed to Fluoride.
  31. Adedara IA, Ojuade TJ, Olabiyi BF, et al. Taurine Ameliorates Renal Oxidative Damage and Thyroid Dysfunction in Rats Chronically Exposed to Fluoride.
  32. Zhou JC, Wu ZC, Chen ZJ, et al. Clinical Effect of Acupuncture on Endemic Skeletal Fluorosis:A Randomized Controlled Trial. Evid Based Complement Alternat Med, 2013, 2013:839132.
Casey J Krol

Casey J Krol

The guy exposing the truth about fluoride, one great article at a time. Now if you’d like to support what I do, click the “donate” button below. While for any questions, use the other buttons to get in touch with me (IG or Twitter). Better yet, sign up with your email on the website and get access to my personal email.

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