Several studies have investigated the potential health benefits, including those associated with neurological function, of the n-3 fatty acid DHA. This has arisen in part because of the association between higher intakes of fish, which is a major dietary source of DHA, and reduced disease risk. In addition to DHA, fish also provides choline and vitamin D. The objective of the present study was to assess whether women in the first half of pregnancy with low fish intake also had low blood concentrations of vitamin D, choline and DHA. A total of 222 pregnant women at 16 weeks of gestation were examined for dietary intake, erythrocyte (phosphatidylethanolamine PE) DHA, plasma free choline and 25-hydroxyvitamin D (25(OH)D). Women who consumed ≤ 75 g fish/week (n 56) compared to ≥ 150 g fish/week (n 116) had lower dietary intake of DHA, total choline and vitamin D (P< 0·001), and lower erythrocyte PE DHA (5·25 (sd 1·27), 6·83 (sd 1·62) g/100 g total fatty acid, respectively, P< 0·01), plasma free choline (6·59 (sd 1·65), 7·40 (sd 2·05) μmol/l, respectively, P= 0·023) and 25(OH)D (50·3 (sd 20·0), 62·5 (sd 29·8) nmol/l, respectively, P< 0·01). DHA intake was positively related to the intake of vitamin D from foods (ρ 0·47, P< 0·001) and total choline (ρ 0·32, P< 0·001). Dietary intakes and biomarkers of DHA, choline and vitamin D status were assessed to be linked. This raises the possibility that unidentified concurrent nutrient inadequacies might have an impact on the results of studies addressing the benefits of supplemental DHA.