Translations:Riboflavin/45/en

In the early 1900s, several research laboratories were investigating constituents of foods, essential to maintain growth in rats. These constituents were initially divided into fat-soluble "vitamine" A and water-soluble "vitamine" B. (The "e" was dropped in 1920.) Vitamin B was further thought to have two components, a heat-labile substance called B₁ and a heat-stable substance called B₂. Vitamin B₂ was tentatively identified to be the factor necessary for preventing pellagra, but that was later confirmed to be due to niacin (vitamin B₃) deficiency. The confusion was due to the fact that riboflavin (B₂) deficiency causes stomatitis symptoms similar to those seen in pellagra, but without the widespread peripheral skin lesions. For this reason, early in the history of identifying riboflavin deficiency in humans the condition was sometimes called "pellagra sine pellagra" (pellagra without pellagra).