To the Editor:—We would like to bring to the attention of your readers certain inconsistencies and inaccuracies in the article "Physiological Availability of Vitamin A from Capsules" by A. E. Sobel and A. A. Rosenberg appearing in the November issue.
The article draws a comparison between the serum vitamin A levels in adults fed large numbers of three different capsules and a reference oil of vitamins A and D. One of the products studied was our preparation "vi-aqua," identified as product "C."
In attempting to explain wide differences in vitamin A absorption claimed by the investigators, they attribute the differences to variations in the disintegration time required for the three different capsules. Here their data appear to be completely erroneous.
The authors claim that in a pepsin solution, capsule C ("vi-aqua") did not disintegrate for four hours, while the other two capsules in the study disintegrated in a matter