It should also be considered that due to the low pH in the stomach, the increased dissolution of the TiO₂ particles may increase its bioavailability and may facilitate the entry of titanium ions into the blood circulation. Despite the relatively large consumption of TiO₂ as a food additive, no studies on the effect of pH on its absorption and bioavailability have been found in the literature. This can be attributed to a general belief that TiO₂is completely insoluble. However, this is not completely true, as TiO₂ particles show a certain degree of solubility.

Animal studies have shown that, when consumed as a food additive, titanium dioxide can induce intestinal inflammation.

Titanium dioxide (TiO2) is a chemically inert inorganic compound and an insoluble white solid that occurs naturally in several minerals, including rutile, anatase, and brookite. It is created synthetically from the mineral ilmenite. It is an insoluble white solid. Anatase, when compared to brookite and routine, has the most industrial applications, but it is the most toxic form of TiO2.

The EU expert panel did not identify an immediate health concern linked to TiO₂ when used as a food additive. However, due mainly to uncertainties concerning the safety of TiO₂ nanoparticles, the panel concluded that TiO₂ as a food additive (E171) could no longer be considered safe.