Diet during pregnancy in a population of pregnant women in South West England. ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood.

OBJECTIVE: To describe the diet of a population of pregnant women.
SUBJECTS: Eleven thousand, nine hundred and twenty-three pregnant women resident in the south-west of England.
DESIGN: A self-completion unquantified food-frequency questionnaire was sent to the women at 32 weeks gestation. Estimated daily nutrient intakes were calculated from the answers to the questionnaire.
RESULTS: On the whole, nutrient intakes of the pregnant women in this survey compared very closely with the reported nutrient intakes for all women aged 16-64 in the last Dietary and Nutritional Survey of British Adults (DNSBA). The exceptions were sugar, calcium, folate and vitamin C where the estimated intakes were somewhat higher, and retinol, where the estimated intake was somewhat lower than the DNSBA. Mean and median estimated nutrient intakes were above the RNIs for the majority of nutrients investigated except for energy, iron, magnesium, potassium and folate. Levels of supplementary vitamin and mineral use were fairly low, the two most commonly taken supplements were iron--taken by 22.5% of the pregnant women before 18 weeks and 43% at 32 weeks, and folate, taken by 9% and 18% of the women, respectively.
CONCLUSIONS: These results suggest that the diets of pregnant women in this country are likely to contain adequate amounts of most nutrients, the most likely exceptions being iron, magnesium, potassium and folate. The relatively low intakes of folate and small proportion of women taking folate supplements is of concern, because of the association between inadequate amounts of folate in the diet and neural tube defects.