To investigate the nutritional status of the population of the UK during the Second World War, nutritional surveys were commissioned in 1941. These included surveys of two groups of pregnant women: the first comprised 120 working-class women who were studied in the spring of 1942, and a second group of 253 women in 1944. Both groups were followed up until after delivery. Detailed biochemical assessments were performed on each subject. Our statistical analysis of the haematological data showed that nearly 25 % of women from the 1942 group were deficient in protein, over 60 % were deficient in Fe and vitamin A, and over 70 % had severe vitamin C deficiency. The findings were reported to the Ministries of Health and Food who instigated a food supplementation policy at the end of 1942 that entitled pregnant women in the UK to extra rations of fruit, dairy produce and to a supply of cod-liver-oil tablets. A second group of 253 pregnant women were studied 15 months later which enabled the effects of this programme to be investigated. Supplementation reduced the proportion of women with vitamin A concentrations below the normal range from 63 % to 38 %, and vitamin C from 78 % to 20 %, but protein and Fe concentrations were not increased but actually declined. These findings continued to exert an influence over government food policy for pregnant women until the abolition of rationing in 1954.