Footnotes to food tables. 2. The underestimations of intakes of lesser B vitamins by pregnant and lactating women as calculated using the fourth edition of McCance and Widdowson's 'The composition of foods'.

In McCance & Widdowson's 'The composition of foods' many items lack information on the content of the lesser B vitamins, and dietary intakes can therefore be underestimated. The degree of this underestimation was assessed using data from a longitudinal study of the food intake of 63 pregnant and lactating mothers in Cambridge, UK, with a total of 3185 days of weighed diet records. The extra mean daily additional intake of each vitamin contributed by foods eaten by the mothers but lacking data in the food tables was estimated to be: vitamin B12, 0.1 micrograms, (1.5 per cent of total intake); vitamin B6, 0.04 mg (3.3 per cent); total folate, 10 micrograms (5.3 per cent); pantothenic acid, 0.6 mg (11.5 per cent); and biotin, 5 mg (14.3 per cent). Although many items in the tables lack data, most were eaten infrequently and made little contribution to vitamin intake. It was estimated that, if data were added for a limited number of frequently-eaten foods, namely, white toast, baked beans, biscuits, breakfast cereals and 'chicken with skin', then intakes of all five vitamins would be underestimated by less than 4 per cent.