Fluoride is found in the air, soil, water, and nearly all foods. Volcanic activity, weathering, and the fumes discharged by various chemical industries release fluorides into the environment. Fluoride plays a crucial role in bone and dental health. Most of the fluoride in organisms is found in calcified tissue, where it stimulates the formation of new bone tissue and protects tooth enamel from the acids that cause tooth decay. There are two types of fluoride: calcium fluoride and sodium fluoride. 


What does fluoride do? 

Helps prevent the onset of tooth decay by: 

  • Inhibiting the activity of bacteria that cause dental plaque;
  • Making enamel less acid-soluble;
  • Promoting enamel remineralization;
  • Halting the process of enamel decalcification;
  • Stopping the progress of tooth decay.

Stimulates the formation of new bone tissue. 


The recommended fluoride dose is given in milligrams per day. Adequate intake (AI) of fluoride is based on the amounts that are optimal for reducing the onset of tooth decay in a group of individuals without causing adverse reactions. 

If drinking water contains less than 0.3 ppm (parts per million) of fluoride: 

Adequate Intake* (AI) of Fluoride According to the Canadian Paediatric Society.
Birth to 6 months
6 months to 3 years
3 to 6 years
Over 6 years

Source: Canadian Paediatric Society.

If drinking water contains more than 0.3 ppm (parts per million) of fluoride: no supplementation.

Note: The recommendations of the Canadian Dental Association take into account individual variations such as weight and fluoride intake from non-water sources and are as follows:

  • 0.05 to 0.07 mg/kg/day (all sources).


About 40% of the Canadian population receives fluoridated water. The fluoride concentration of most foods is well below 0.05 mg/100g*, with the exception of fluoridated water (bottled and tap), beverages (including tea), certain ocean fish (especially if eaten with bones), and some commercial infant formulas that are made or reconstituted using fluoridated water. Fluoride is also found in table salt, toothpastes, and mouthwashes. 

 Some of the foods containing fluoride are listed below: 

  • Beer;
  • Wheat germ;
  • Chocolate milk;
  • Carrots;
  • Corn;
  • Eggplant;
  • Curly kale;
  • Potatoes;
  • Spinach and water cress;
  • Green beans;
  • Onions;
  • Honey;
  • Meats and offal;
  • Almonds and hazelnuts.

Note: It is important to know whether or not your municipality’s drinking water is fluoridated.


Inadequate fluoride intake increases the risk of tooth decay. 

Signs of fluoride deficiency: 

  • Decreased resistance to tooth decay. 

Adverse effects

Children under six who ingest large quantities of fluorides during the tooth formation period can develop dental fluorosis. Fluorosis alters the appearance of teeth (white or brownish spots) and can cause pain or trouble chewing but does not alter tooth function. The risk disappears around age six or seven since the teeth are formed. 

Adults exposed to high quantities of fluorides over a long period can develop skeletal fluorosis. Skeletal fluorosis is a progressive disease that increases bone density and makes bone more and more brittle. This condition causes joint stiffness and pain. Severe cases can involve a calcification of the ligaments, muscular wasting, and neurological problems attributable to hypercalcification of the vertebrae. 

Signs of excess fluoride:

  • Gastric discomfort (at high doses);
  • Nervous and immune system damage;
  • Hypocalcemia;
  • Hypoglycemia;
  • Fluorosis of tooth enamel;
  • Bone fluorosis.


  • Fluoride is contraindicated in individuals suffering from renal insufficiency (a possible cause of fluoride poisoning) and people with a history of fluoride poisoning. 

NOTE: To ensure your fluoride intake does not exceed the optimal level recommended for healthy teeth: 

  • Do not give fluoridated mouthwash to children under age six as they may swallow some of it;
  • Talk to your dentist before using a fluoridated mouthwash;
  • Health Canada does not recommend the use of fluoride supplements (in the form of droplets or tablets)p;
  • Ensure that children under six are supervised when they brush their teeth and children under three have their teeth brushed for them by an adult, without toothpaste;
  • Ensure that children over three do not use more than a pea-sized dab of toothpaste;
  • Explain to children the importance of not swallowing toothpaste.


Natural health products and vitamin supplements (decrease in fluoride absorption): 

  • Calcium**;
  • Magnesium **;
  • Iron**.

A food that can cause decreased fluoride absorption: 

  • Milk**.

Drugs that can decrease fluoride absorption: 

  • Medications to relieve heartburn**.

Additional information

**When taking the above drugs or products, wait two hours between doses.

***Speak with your pharmacist if you plan to take fluoride supplements. Your pharmacist can help you choose the solution that’s best for you based on your health and any drugs you take.

Other names

Fluoride, Fluorine