Vitamin A and carotene in British and American diets

Abstract

1. The confusion sometimes found in discussions of dietary vitamin A and its precursors is illustrated. The relative potency of vitamin A and carotene is briefly discussed, and the procedure used in the National Food Survey of Great Britain explained. 2. Changes in the vitamin A and carotene contents of the British diet over the last two decades are illustrated. 3. The vitamin A and carotene contents of the American diet are estimated, and compared with those of the British diets; both estimates of intake are compared with recommended allowances. The difficulties of making such comparisons are discussed, in view of the different conventions used in the two countries. 4. An appendix, on the calculation of vitamin A in the diet, is included, in which interrelations between different methods of expressing vitamin A value are shown.