Typical fluoride intakes from formula feeding using fluoridated water at the levels of fluoridation used in New Zealand are safe, and there is no evidence of any adverse effects on infant health or child development.
Ministry of Health’s advice on infant formula and breastfeeding
The Ministry of Health promotes breastfeeding as the best source of food for infants and recommends that New Zealand mothers breastfeed their babies exclusively to around 6 months of age, with continued breastfeeding until at least 12 months of age, and beyond. You can find out more at Healthy Eating Guidelines for New Zealand Babies and Toddlers (0-2 years old).
New Zealand guidelines to manage fluoride in infant formula
Infant formula in New Zealand is regulated under Standard 2.9.1 of the Australia New Zealand Food Standards Code. Under this standard, adding fluoride to infant formula during the manufacturing process is not permitted. Companies manufacturing and selling infant formula in New Zealand must comply with the Australia New Zealand Food Standards Code.
The Australia New Zealand Food Standards Code also specifies that powdered or concentrated infant formulae containing naturally higher levels of fluoride must indicate on the label that consumption may cause dental fluorosis and should be discussed with a medical practitioner or other health professionals. That is, those containing more than 17μg of fluoride per 100 kilojoules (prior to reconstitution), or ‘ready to drink’ formulae containing more than 0.15mg fluoride per 100mL.
Reconstituting infant formula with fluoridated water
The Royal Society of New Zealand and Office of the Prime Minister’s Chief Science Advisor 2014 review of international evidence concluded that there is no evidence that typical fluoride intakes from formula feeding, using optimally fluoridated water for reconstitution, has any adverse effects on infant health or child development aside from a possible greater risk of mild dental fluorosis.
Dental fluorosis is a defect of the tooth enamel caused by a high ingestion of fluoride during the development of the tooth. It is characterised by opaque white areas in the enamel. In its mild form, the opacities are only really visible to dental health professionals under close examination and have no more than cosmetic significance. Recent longitudinal research from Australia also shows that these fade over time. There have been no reported cases of disfiguring fluorosis associated with the fluoridation of water supplies in NZ.
Fluoridated water in New Zealand is safe for use in infant formula, although, as with recommendations elsewhere, if parents are concerned about the risk of mild fluorosis, low-fluoride bottled water can be used for reconstitution.
The American Dental Association have provided evidence-based recommendations suggesting that infant formula can be made up with ‘optimally fluoridated’ drinking water (now 0.7 mg/L in the US), but that parents should be aware of the potential risk of mild enamel fluorosis. If fluorosis is a concern, carers can use ready-to-feed formulae or powdered formulae reconstituted with low-fluoride water.
Advice from Australia indicates that infant formula is safe for consumption whether reconstituted with fluoridated or non-fluoridated water. In 2006, the Australian Research Centre for Population Oral Health at the University of Adelaide published the outcome of an expert workshop on fluoride use in Australia. The workshop concluded that, while there had historically been some infant formula powders with high fluoride content, infant formula products now have very low levels of fluoride, and that infant formula is safe for consumption by infants whether reconstituted with fluoridated or non-fluoridated water.