provitaminn.

Brit.

/prəʊˈvɪtəmɪn/,

/prəʊˈvʌɪtəmɪn/, U.S.

/proʊˈvaɪdəm(ə)n/

Forms: also with hyphen.

Origin: Formed within English, by derivation; modelled on a German lexical item. Etymons: pro- prefix², vitamin n.

Etymology: < pro- prefix² + vitamin n., after German Provitamin (Windhaus & Hess 1926, in Nachrichten von der Königl. Ges. der Wissensch. zu Göttingen (1927) 175).

Biology.

A substance which is converted into a vitamin within an organism. Frequently with following capital letter specifying the vitamin.

ΚΠ

1927 O. Rosenheim & T. A. Webster in Lancet 5 Feb. 306/2 These observations suggest that the provitamin (we propose to use this convenient term, suggested by Prof. Windhaus, for the parent substance of vitamin D) is destroyed by bromine.

1943 Endeavour Apr. 73/2 It became evident that, though the diets of the tropical natives were often deficient in the calcifying vitamin,..they really had ample supplies because of the action of sunlight on the provitamin.

1976 H. Campion et al. in B. E. C. Nordin Calcium, Phosphate & Magnesium Metabolism xii. 445 The two principal pro~vitamins D, ergosterol..and..7-dehydrocholesterol..are formed in vivo by two very similar routes.

1995 Independent on Sunday 27 Aug. (Real Lives section) 11/3 The good news is that pro-vitamin B5 does give hair ‘body’, that is, it draws water into it and swells the strands.

This entry has been updated (OED Third Edition, September 2007; most recently modified version published online March 2022).

单词	provitamin
释义	provitaminn. Brit. /prəʊˈvɪtəmɪn/, /prəʊˈvʌɪtəmɪn/, U.S. /proʊˈvaɪdəm(ə)n/ Forms: also with hyphen. Origin: Formed within English, by derivation; modelled on a German lexical item. Etymons: pro- prefix², vitamin n. Etymology: < pro- prefix² + vitamin n., after German Provitamin (Windhaus & Hess 1926, in Nachrichten von der Königl. Ges. der Wissensch. zu Göttingen (1927) 175). Biology. A substance which is converted into a vitamin within an organism. Frequently with following capital letter specifying the vitamin. ΚΠ 1927 O. Rosenheim & T. A. Webster in Lancet 5 Feb. 306/2 These observations suggest that the provitamin (we propose to use this convenient term, suggested by Prof. Windhaus, for the parent substance of vitamin D) is destroyed by bromine. 1943 Endeavour Apr. 73/2 It became evident that, though the diets of the tropical natives were often deficient in the calcifying vitamin,..they really had ample supplies because of the action of sunlight on the provitamin. 1976 H. Campion et al. in B. E. C. Nordin Calcium, Phosphate & Magnesium Metabolism xii. 445 The two principal pro~vitamins D, ergosterol..and..7-dehydrocholesterol..are formed in vivo by two very similar routes. 1995 Independent on Sunday 27 Aug. (Real Lives section) 11/3 The good news is that pro-vitamin B5 does give hair ‘body’, that is, it draws water into it and swells the strands. This entry has been updated (OED Third Edition, September 2007; most recently modified version published online March 2022). < n.1927
随便看	to have a hen on to have a history to have a hoary head and a green tail to have a hollow leg to have a hollow legs to have a job to have a lash to have a lash at to have a laugh to have a leg to have a leg up on to have a licence to print money to have a life of its own to have a little miss of to have a load to have a lock on to have a lock on something to have a log to roll to have a long head to have a long tongue to have a long way to go to have a look to have a look around to have a look of to have a look round