What are the side effects of fluoride?

From the Guidelines

Fluoride can cause significant side effects, particularly when consumed in excessive amounts, and its use should be carefully managed to minimize risks to morbidity, mortality, and quality of life. The most common side effect is dental fluorosis, which appears as white spots or streaks on teeth due to overexposure during tooth development in children 1. In adults, excessive fluoride intake may lead to skeletal fluorosis, causing joint pain, stiffness, and bone structure changes. Some people may experience gastrointestinal issues like nausea, vomiting, or abdominal pain when taking fluoride supplements. Allergic reactions, though rare, can include skin rashes, itching, or more severe symptoms. At extremely high doses (far above recommended levels), fluoride can cause serious toxicity affecting multiple organ systems.

Key considerations for minimizing fluoride side effects include:

• Using fluoride toothpaste at recommended levels, with children using only a pea-sized amount and being supervised to prevent swallowing 1
• Following package directions for fluoride products
• Being aware of the potential for excessive fluoride intake from multiple sources, including drinking water and supplements
• Monitoring for signs of fluoride toxicity, such as gastrointestinal issues or allergic reactions

Recent studies have highlighted the importance of careful fluoride management, with some research suggesting a potential link between high fluoride levels and reduced intelligence in children 1. Additionally, an increased prevalence of cardiac complications has been observed in residents of fluorosis endemic areas chronically exposed to fluoride 1. As such, it is essential to prioritize careful fluoride use and monitoring to minimize potential side effects and ensure the benefits of cavity prevention outweigh the risks.

From the FDA Drug Label

ADVERSE REACTIONS Developing teeth of children under age 6 may become permanently discolored if excessive amounts are repeatedly swallowed. The following adverse reactions are possible in individuals hypersensitive to fluoride: eczema, atopic dermatitis, urticarial, gastric distress, headache, and weakness. OVERDOSAGE If treatment dose is swallowed (less than 100 mg F ion), administer milk, limewater, or calcium-type antacid. In case of larger doses, use ipecac syrup emetic and immediately seek medical help. Overdose symptoms include nausea, vomiting, diarrhea, and abdominal pain.

The possible side effects of fluoride include:

• Permanent discoloration of developing teeth in children under 6 years old if excessive amounts are swallowed
• Hypersensitivity reactions such as:
  • Eczema
  • Atopic dermatitis
  • Urticarial
  • Gastric distress
  • Headache
  • Weakness
• Overdose symptoms:
  • Nausea
  • Vomiting
  • Diarrhea
  • Abdominal pain 2 2

From the Research

Fluoride Side Effects

• Fluoride can reduce the incidence of dental caries and fluoridation of drinking water can provide such protection 3
• Moderate dental fluorosis occurs in 1 to 2% of the population exposed to fluoride at 1 mg/l in drinking water and in about 10% of the population at 2 mg/l 3
• The issue of whether moderate or severe dental fluorosis represents an adverse health effect is still controversial 3
• There is no evidence of skeletal fluorosis among the general U.S. population exposed to drinking water fluoride concentrations lower than 4 mg/l 3
• Some individuals may experience hypersensitivity to fluoride-containing agents 3
• Fluoride exposure may have various adverse health effects, including affecting thyroid function and disease risk 4
• Exposure to high-fluoride drinking water appears to non-linearly affect thyroid function and increase TSH release in children, starting above a threshold of exposure 4
• Low-moderate fluoride exposure is associated with alterations in childhood thyroid function that may modify the association between fluoride and intelligence 5

Acute Toxicity

• Acute toxicity can occur after ingesting one or more doses of fluoride over a short time period which then leads to poisoning 6
• Poisoning is mainly due to unsupervised ingestion of products for dental and oral hygiene and over-fluoridated water 6

Safety and Benefits

• The topical use of fluoride is safe 6
• The European Academy of Paediatric Dentistry (EAPD) recommends a preventive topical use of fluoride supplements because of their cariostatic effect 6
• Fluoride can maximize the benefits and minimize the risks for the safe and effective prevention of dental caries 7