Comparison of fluoride level between mother’s milk and infant formula milk – a global systematic review and dental fluorosis risk assessment

Dental Fluorosis (DF) is one of the negative outcomes of excessive fluoride (F) intake through food sources. This systematic review aimed to compare F content in two important food sources for infants, Mother's Milk (MoM) and Infant Formula (IF), and then evaluate the risk of DF related to F in those two types of food. For this purpose, 181 studies were initially found by searching the relevant keywords in widely recognized databases, including Google Scholar, Scopus, Science Direct, and PubMed. Then, 29 final studies were selected considering the inclusion and exclusion criteria. The results showed that the F level of MoM in five out of nine (55.5%) studies and its overall average worldwide does not comply with the European Food Safety Authority (EFSA) guideline (100 µg/L). Therefore, MoM's value of F must be continuously monitored, and risk mitigation solutions must be used to reduce F. Accordingly, tracking F in drinking water, tea, and food consumed by lactating mothers (LMs) was the essential measure that could lead to the reduction of F of MoM. The level of F of IF was much lower than its value in MoM. The estimated hazard quotient (HQ) of DF for both types of food was lower than the acceptable level (HQ = 1), but, due to other sources of F intake, it is necessary to use control solutions to reduce the level of F in MoM and IF consumed by infants.