The History of Vitamin H, I, and J.

The terms “vitamin H,” “vitamin I,” and “vitamin J” refer to substances that were once considered vitamins but are either now known by a different name or are no longer considered essential for human nutrition. Here is a brief history of each:

Vitamin H (Biotin)

• Discovery: The history of vitamin H is somewhat complex because it was discovered and named by several different researchers at the same time.¹ During the early 20th century, scientists were studying a growth factor for yeast, which they called “bios.”
  
• “Egg-White Injury”: A key development came from the study of “egg-white injury.³ In the 1920s, researchers observed that rats fed a diet consisting almost entirely of raw egg whites developed symptoms like dermatitis (skin rashes), hair loss (alopecia), and loss of muscle coordination.
  
• Naming: In 1939, biochemist Paul György, working on the egg-white injury problem, isolated a molecule from eggs that seemed to be an essential nutrient. He named it “vitamin H” from the German words for hair (Haar) and skin (Haut) because of its connection to the symptoms he observed.
  
• Official Designation: It was soon realized that vitamin H was the same substance that other teams had called “biotin” (from the Greek word biotos meaning “life”) and “coenzyme R.” In the 1960s, after its structure was fully established, it was officially designated as biotin, and is now known as vitamin B7. The egg-white injury was later found to be caused by a protein in raw egg whites called avidin, which binds to biotin and prevents its absorption in the gut.
  

Vitamin I

• No Official Vitamin I: There is no substance officially recognized as “vitamin I” for human nutrition. The sequential naming of vitamins (A, B, C, D, etc.) followed the order of their discovery, and some letters were skipped or later reclassified.
• The “Vitamin” Concept: The history of “vitamin I” is part of the broader history of the discovery of vitamins. Early in the 20th century, scientists like Christiaan Eijkman and Casimir Funk were working on understanding diseases like beriberi. Eijkman observed that chickens fed polished rice developed a form of polyneuritis, while those fed unpolished rice did not, leading him to believe the husks contained an important nutrient.
  
• Casimir Funk and “Vitamine”: In 1912, Casimir Funk coined the term “vitamine” for these “vital amines” he believed were essential for life. The initial “vitamin” he isolated was later identified as thiamine, or vitamin B1, which prevents beriberi. The “I” in the alphabetical sequence was simply never assigned to a distinct vitamin.
  

Vitamin J

• No Official Vitamin J: Similar to vitamin I, there is no official “vitamin J” in the standard list of essential human vitamins.
• Early Research: Some historical accounts suggest “vitamin J” was a term for a substance found to be beneficial for guinea pigs but not considered necessary for humans.
  
• Modern Interpretations: The term has sometimes been used colloquially to refer to other substances. For example, some sources have used “vitamin J” as a marketing term for Choline, which is an essential nutrient but not officially classified as a vitamin by most regulatory bodies. In some more recent, non-scientific contexts, “vitamin J” has even been humorously or metaphorically used to refer to “joy.”
  

Prosper and be in health.