Vitamins in Western diets

Vitamins are now available at reasonable prices, much is known about modes of action and there is a rich literature on dietary surveys. Forty years ago the classical deficiency diseases were rampant and Edward Mellanby used to say that the difficulty was ‘to get vitamins down the throats of those who need them’. Since that time normal diets have improved and welfare schemes have been adopted so that beriberi, pellagra, ariboflavinosis, rickets and scurvy have become rare in many countries. Free orange-juice and cod-liver oil for infants, the enrichment of white flour and the vitaminization of margarine contributed significantly to the improved situation (cf. Aykmyd, Joliffe, Lowry, Moore, Sebrell, Shank, Tisdall, Wilder & Zamecnik, 1949; Goldsmith, Darby, Steinkamp, Beam & McDevitt, 1950). Enrichment suits countries where staple foods are processed commercially, but is difficult where subsistence farming predominates. Nevertheless, even in India, fortification is in the short run the best way to reach a large number of people at little cost (Berg, 1973). The price of synthetic vitamins decreases sharply with increasing utilization, and enrichment affords a cheap insurance, with practically no risk of hypervitaminosis. Margarine, once an inferior substitute for butter, is now in some respects a superior product; it contains vitamins A and D in stated amounts with no seasonal variations and is a good source of tocopherols and of essential fatty acids. In the UK average intakes of vitamins exceed recommended daily allowances for all age groups and overt deficiency is very rare. This is true for many advanced countries but increasing heterogeneity of populations and diets raises complex issues, especially concerning the adaptation of immigrants to new surroundings. There is a great deal of evidence that despite satisfactory average intakes a significant minority of the population obtains less than the recommended allowance of one or more of the vitamins used as nutritional yardsticks. Woodhill (1970) reported from Australia that intakes of vitamin A, p-carotene and thiamin were satisfactory but ascorbic acid intakes were low for a group of nineteen men (see Table I). The difference between men and women needs further study (see also Brin, Dibble, Peel, McMullen, Bourquin & Chen, 1965). Women may possess a limited capacity for ascorbic acid synthesis. In the USA a national appraisal of nutritional status has been undertaken. This is an immense task full of difficulties which make it necessary to revise procedures. Coursin (1970) reported briefly on the basis that dietary intakes below 70% of the