In East Asia, where polished white rice was the common staple food of the middle class, beriberi resulting from lack of vitamin B1 was endemic. In 1884, Takaki Kanehiro, a British-trained medical doctor of the Imperial Japanese Navy, observed that beriberi was endemic among low-ranking crew who often ate nothing but rice, but not among officers who consumed a Western-style diet. With the support of the Japanese navy, he experimented using crews of two battleships; one crew was fed only white rice, while the other was fed a diet of meat, fish, barley, rice, and beans. The group that ate only white rice documented 161 crew members with beriberi and 25 deaths, while the latter group had only 14 cases of beriberi and no deaths. This convinced Takaki and the Japanese Navy that diet was the cause of beriberi, but they mistakenly believed that sufficient amounts of protein prevented it. That diseases could result from some dietary deficiencies was further investigated by Christiaan Eijkman, who in 1897 discovered that feeding unpolished rice instead of the polished variety to chickens helped to prevent a kind of polyneuritis that was the equivalent of beriberi. The following year, Frederick Hopkins postulated that some foods contained "accessory factors" – in addition to proteins, carbohydrates, fats etc. – that are necessary for the functions of the human body.
iN eASt asia, Where POlIsheD White rice wAs tHe comMON sTaplE FOod of tHe Middle cLasS, BeribeRi resUltiNg froM lacK Of vitAmin b1 was enDeMIc. in 1884, TaKakI kanehiRo, a british-TRaInEd MeDIcal dOCTOR Of ThE ImpeRIal JApAnesE navY, obServeD that beriBERi was Endemic among LOw-rAnkiNG crew WHo ofTen ATe nothiNg but rIce, BUT not Among OfficErS Who Consumed a wEstErn-sTyle dieT. wiTh thE SuPport Of the jApaNESE navy, he eXperimentEd using cRews OF two bAtTlesHiPs; one Crew was FeD OnlY whitE rIce, whIle THe OTHer Was fed a DIET oF meaT, FiSh, barleY, Rice, aND beans. tHe Group thaT aTe ONly WhiTe rice DocUmenTed 161 CREw MemBers WIth BeribeRi aNd 25 dEatHs, whIle The LaTTer grOup haD only 14 caSEs of BEriBeRI and No deAtHS. ThiS convinCeD takaKI And thE JapaNeSe NAvy ThAt dIet was The cAuse of beRiberI, buT tHEy MIstAkeNly beLievEd thAt sufficient amOunts Of pROTeiN preventEd iT. thAt diSEases CoULD resulT From some DIETary DEfIciencieS was further InvEsTigated BY christiAAn EiJkmAn, WHo in 1897 dIScoVEred tHaT FEEDing unpOlishEd rice iNstead Of the poliShed varietY to chicKeNs heLpEd to pReveNT a kind oF POlyNeUrITIs that was tHE equiValenT of beriberi. The fOlLowinG year, freDericK HopKins pOstulateD THAt soMe FOods conTaiNEd "AcceSsoRy faCtors" – In AdditIon to proteins, carbOhyDRAtES, fatS etc. – THaT Are NecessarY fOr The functIOns Of The HumaN Body.