Vitamin T, or torulitine, is a substance found in egg yolks and sesame seeds. It is thought by some to improve memory and concentration, and to help strengthen red blood cells. In spite of its name, Vitamin T doesn't meet the standard definition for being a vitamin. Indeed, many don't consider it to be a vitamin at all. Despite its purported health benefits in certain circles, very little is actually known about it. Vitamin T may be heard more often in its use as a slang term for testosterone or tequila.
A true vitamin is generally defined as a nutrient that, in small doses, is important to regulating metabolism in the body. A, B, C, D, E and K vitamins all fit this definition. In the case of Vitamin T, however, there is no consensus that the substance meets this criterion. Most resources do not include it, even informally, in their listings of vitamins.
Vitamin T is water-soluble, and can be destroyed by alcohol. It's found in egg yolks, sesame seeds, as well as the sesame seed paste, tahini. Due to its prevalence in sesame seeds, it's also known as the Sesame Seed Factor. Although little is agreed upon about its health benefits, most sources do seem to indicate that it has been associated with strengthening red blood cells. By bolstering blood cells, the substance may be an effective combatant in blood-cell related ailments, such as anemia and blood hemolysis.
Not being recognized as a vitamin—or even as an important health supplement—by many medical experts poses some difficulties for those wishing to factor Vitamin T into a diet. All vitamins have a recommended dietary allowance (RDA) that informs exactly how much of a particular nutrient a person should consume per day. RDAs also help determine what a nutrient's toxic levels are, and what symptoms will result in the case of an overdose. None of this information, however, is known about this so-called vitamin, making it hard to assess whether one should be consuming it regularly, and in what quantities.
Most vitamins come in a supplemental form as well as in their natural food groups. Vitamin T, on the other hand, is hard to locate outside of eggs and sesame seeds. Anyone looking to add this so-called vitamin to their daily dose of vitamin caplets may find it difficult to track down a supplement. This, again, is probably a side effect of Vitamin T not being well understood, and therefore not adopted by many medical organizations or health food suppliers.