An Unidentified Water-Soluble Factor in Alfalfa Which Improves Utilization of Vitamin A

Abstract

Supplements of a water-soluble extract from alfalfa increased the length of time required for depletion, the maximum weight increment attained and the length of survival of rats fed a purified diet deficient in vitamin A. The alfalfa extract also prolonged the survival time of rats depleted of vitamin A and caused weight increase in such rats following administration of a suboptimal amount of vitamin A. It could not, however, replace completely the carotene or vitamin A in the diet as evidenced by the fact that the weight of rats fed the basal vitamin A-free diet supplemented with the alfalfa extract eventually plateaued and the rats developed symptoms of vitamin A deficiency. The active factor (or factors) in alfalfa is distinct from any of the known nutrients.