Comparison of breast milk vitamin A concentration measured in fresh milk by a rapid field assay (the iCheck FLUORO) with standard measurement of stored milk by HPLC.

Availability of rapid, point-of-contact analytical methods would facilitate the use of breast milk vitamin A concentration (BMVA) to assess vitamin A (VA) status. We compared BMVA concentrations measured by high-performance liquid chromatography (HPLC) (the standard technique) with those by iCheck FLUORO, a new portable fluorometer that can rapidly quantify BMVA. Casual breast milk samples (n=154) were collected during a representative survey in Yaoundé and Douala, Cameroon. Milk fat and BMVA concentrations (by iCheck) were measured in fresh milk in the field. After storage at <-20 °C, BMVA concentrations were also measured by HPLC. BMVA values from the two methods were highly correlated (R(2)=0.72 for BMVA/l; R(2)=0.62 for BMVA/g fat, both P<0.0001). HPLC values were greater than iCheck values on average, and the difference increased with increasing BMVA. The iCheck FLUORO could be useful for monitoring fortification programs, but before-after surveys to assess change in BMVA concentrations should use one method consistently.