The New Zealand Ministry of Health recommends fluoride is added to public water supplies to a concentration of 0.7–1.0 mg/L. Fluoride is added to municipal water in Palmerston North.
To assess fluoride intakes among self-selecting pregnant women in Palmerston North.
Pregnant women (n = 59) were recruited from Palmerston North (2009–2011). Daily urinary fluoride excretion (DUFE) was determined by measuring fluoride concentration in 24-h urine samples at an IANZ accredited laboratory (Hill Laboratories, Hamilton) using an ion selective electrode. Total daily fluoride intake (TDFI) was estimated using extrapolation, based on 50% of ingested fluoride being excreted in urine and also using a prediction equation based on healthy adults (TDFI = (DUFE 0.29)/0.54); pregnancy has little effect on fluoride metabolism.
Median urinary fluoride concentration was 0.82 (0.62, 1.03) g/mL. Mean DUFE was 1.70 0.78 mg/day. Based on extrapolation, mean TDFI was 3.40 1.56 mg/day; above the AI (3 mg/day) with 26 participants (44%) below the AI. Using the prediction equation, mean TDFI was 2.62 0.91 mg/day; below the AI with 38 participants (64%) below the AI. No participants exceeded the Upper Level (10 mg/day).
Estimates of fluoride intake were lower using the prediction equation than based on extrapolation. The prediction equation suggested inadequate fluoride intakes for these pregnant women. Both methods suggested that toxicity was not a problem as intakes were below the Upper Level. Further research is required to ascertain if fluoride intakes in pregnant New Zealand women are adequate.
Note: Conference Abstract for the Joint Annual Scientific Meeting of the Nutrition Society of New Zealand and the Nutrition Society of Australia: MDPI A