비타민 U가 있다?

방금 전 퀴즈 대한민국에서 친절하게 나와줬습니다.

S-Methylmethionine is sometimes called vitamin U in naturopathic medicine, but it is not recognized as a vitamin by mainstream nutrition science. Methionine in itself has not been demonstrated as effective for treating peptic and duodenal ulcers.[2][3][4] Its proponents claim that sources of methionine are limited, or claim it can be found only in raw cabbage; however, these claims are incorrect. Methionine is a common amino acid found in a wide variety of fruits, vegetables, and legumes. (중략) Dr. Cheney dubbed the unidentified substance(s) responsible for the rapid healing, "Vitamin U", although this is not recognised as a vitamin, rather merely a name. (http://en.wikipedia.org/wiki/S-Methylmethionine)

주류 영양학계에서 비타민으로 인정받고 있지 못하다는데요? (영문 위키백과 내용으로 미루어볼 때, S-Methylmethionine이 네이버 국어사전 검색에서 나오는 '1950년대 양배추즙에서 발견된 지용성 비타민' 맞는 것 같습니다. 일반적으로 비타민 U라고 하면 S-Methylmethionine을 가리키는 것 같구요. "Garnett Cheney, M.D. demonstrated in the 1950s that fresh, raw cabbage juice could significantly increase the rate of healing in patients with gastrointestinal ulceration, and his work was published in peer reviewed journals. [5] [6] [7] [8]"이래요.)
이쪽 분야(생물?)에 관심 많으신 분께서 좀 시원하게 알려주시면 감사하겠습니다.