Orotic acid is an intermediate in pyrimidine metabolism. Orotic acid is not recognized as a vitamin and may even increase hepatic lipids. Vitamin H3 has been promoted as a nutritional substance that decreases the symptoms of diseases related to aging. There is no sound research to support this claim. This compound is not recognized as a vitamin.
Vitamin U is the methylsulfonium salt of methionine.
Vitamin U is found in cabbage and other green vegetables. Claims have been made that vitamin U is an antipeptic ulcer factor. These claims have not been supported by research. This compound is not recognized as a vitamin.