Objective: To estimate fluoride intake through consumption of water from the municipal network in pregnant women and their children from the INMA-Gipuzkoa cohort and to compare these intakes with recommended levels. In Euskadi (Spain), fluoridation of drinking water is compulsory in water supplies for more than 30,000 inhabitants.

Method: 575 pregnant women (recruitment, 2006-2008) and 424 4-year-old children (follow-up, 2010-2012) have been included. Fluoride levels in drinking water were obtained from the water consumption information system of the Basque Country (EKUIS). Water consumption habits and socioeconomic variables were obtained by questionnaire.

Results: 74.9% and 87.7% of women and children consumed water from the municipal network. Average fluoride levels in fluoridated water were 0.805 (SD: 0.194) mg/L during baseline recruitment and 0.843 (SD: 0.080) mg/L during follow up, at 4 years old of the children. Average and 95th percentile of fluoride intake were 0.015 and 0.026mg/kg per day in women and 0.033 and 0.059mg/kg per day in children. Considering only fluoride provided by drinking water, 8.71% of children living in fluoridated areas exceeded intake level recommended by the European Food Safety Authority, consisting in 0.05mg/kg per day.

Conclusion: The results show that ingested levels of fluoride through consumption of municipal water can exceed the recommended levels in children and encourages further studies that will help in fluoridation policies of drinking water in the future.