Relative bioavailability of micronized, dispersible ferric pyrophosphate added to an apple juice drink 

In 2009 researchers assessed the relative bioavailability of SunActive Iron. Fifteen women with low iron were recruited to consume SunActive Fe added to pure apple juice or ferrous sulphate. Absorption and bioavailability were compared in both groups. The authors found that bioavailability of SunActive Fe iron relative to ferrous sulphate was 0.6, indicating that it is a good source of bioavailable iron. 

References:

Roe, M. A., Collings, R., Hoogewerff, J., & Fairweather-Tait, S. J. (2009). Relative bioavailability of micronized, dispersible ferric pyrophosphate added to an apple juice drink. European journal of nutrition, 48(2), 115–119. https://doi.org/10.1007/s00394-008-0770-3