The nutrient intakes of pregnant and lactating mothers of good socio-economic status in Cambridge, UK: some implications for recommended daily allowances of minor nutrients

Abstract

1. Forty-two mothers from social classes I, I1 and IIInon-manual and twenty-one from social classes IIImanual (M), IV and V were studied longitudinally. The mean daily nutrient intakes in months 4–9 of pregnancy, months 2– 4 of lactation and 3 and 6 months post-lactation are presented and are compared with the UK and the US recommended daily allowances (RDA).2. The quality of the diets (nutrients per 4184 kJ (1000 kcal)) was found to be better than that of other adult female populations studied in the UK, except for a group of dietitians.3. The mean daily intakes of nutrients for which there are UK RDA were almost all greater than 100% of the RDA. The exceptions were iron, which in the manual group (social classes IIIM, IV and V) was 85% of the RDA in pregnancy and 75% post-lactation, and vitamin D.4. Among the nutrients for which there are US, but not UK RDA, only phosphorus and vitamin B,, intakes were greater than 100% of the RDA in both groups at all stages of the study. Intakes of other nutrients were below the RDA: pantothenate 7G91, vitamin B, zinc, vitamin E and copper 40–72, folate 21–44, and biotin < 20% of the RDA.5. The bases of the RDA for adult women were examined; for most nutrients the information is limited. It was concluded that the RDA for magnesium, vitamin E and pantothenate are probably higher than necessary and that deficiency is unlikely; that zinc, copper, vitamin B, and folate are probably ‘marginal’ nutrients for ‘at risk’ groups; and that information on biotin is insufficient even roughly to assess the dietary requirement.