Phytosterols can impair vitamin D intestinal absorption in vitro and in mice

Scope: Adequate vitamin D status is necessary and beneficial for health, although deficiency and insufficiency are very common. As cholecalciferol (vitamin D3) structure is close to cholesterol structure, we hypothesized that phytosterols, frequently used to decrease cholesterol, intestinal absorption and consequently to reduce hypercholesterolemia, may also interact with cholecalciferol absorption. Methods and results: β‐Sitosterol effect on cholecalciferol postprandial response was first assessed in mice. We then evaluated the effect of different sterols on (i) cholecalciferol micellar incorporation, (ii) cholecalciferol apical uptake and (iii) basolateral efflux in vitro or ex vivo. In mice, cholecalciferol bioavailability was 15‐fold lower in the presence of β‐sitosterol (p