The influence of lipid droplet size on the oral bioavailability of vitamin D 2 encapsulated in emulsions: an in vitro and in vivo study

was the highest for the emulsions containing the largest droplets. The poor in vitro-in vivo correlation observed in our study may have occurred for a number of reasons: the simulated GIT did not accurately model the complexity of a real GIT; the in vivo approach used did not monitor changes in vitamin levels in the blood over time. Overall, this study suggests that particle size does influence the gastrointestinal fate of encapsulated oil-soluble vitamins, but that further work is needed to establish strong correlations between in vitro and in vivo methods.