Benders'dictionary of nutrition and food technology

495VITAMIN AThe recommended upper limits of habitual daily intake ofretinol are about 12.5 × reference intake for adults, but only 2.5× reference intake for infants. Retinol is also teratogenic inexcess, and for pregnant women the recommended upper limitof daily intake is 3000–3300 µg.vitamin A 2 Old name for dehydroretinol, the form found in liversof freshwater fish; has 40% of the biological activity of retinol.vitamin B complex Old-fashioned term for the various Bvitamins: vitamin b 1 (thiamin), vitamin b 2 (riboflavin), niacin,vitamin b 6 , vitamin b 12 , folic acid, biotin and pantothenic acid.These vitamins occur together in cereal germ, liver and yeast;function as coenzymes; and historically were discovered by separationfrom what was known originally as ‘vitamin B’; hence,they are grouped together as the B complex.vitamin B 1 Thiamin. Thiamin diphosphate is a coenzyme inmetabolism of glucose, and in the citric acid cycle. Thiamintriphosphate has a role in nerve conduction, by activating a chloridechannel. Deficiency, especially when associated with acarbohydrate-rich diet, results in the disease beriberi, degenerationof the sensory nerves in the hands and feet, spreadingthrough the limbs, with fluid retention and heart failure. Relativelyacute deficiency, especially associated with alcohol abuse,