What do systematic reviews say?

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Femoral-fracture risk was mildly U-shaped: RR 0.86 at 0.5 mg/L rising to 1.06 at 1.8 mg/L drinking-water fluoride vs null; risk mostly below null across the range; ungraded.

• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 1.8 mg/L vs null
  RR 1.06 [0.67, 1.69]
  Studies not reported
  GRADE not reported
• The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes

  Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 0.5 mg/L vs null
  RR 0.86 [0.71, 1.05]
  Studies not reported
  GRADE not reported