Potency of Vitamin A Acid in the Vaginal Smear Assay

Summary

The biological potency of Vit. A acid was measured by a modified vaginal smear assay and found to be 8% that of Vit. A. The results suggested that the potency of Vit. A acid, relative to that of Vit. A, may vary with the dosing level used. 2-cis and 6-cis Vit. A acid were 50% and 15% respectively as potent as the all-trans form. Vit. A was not spared by daily doses of Vit. A acid.