Objective To assess longitudinally nutrient intakes of lactating women during the postpartum period.Design Dietary data from lactating women were collected by means of 2-day food records at 3 and 6 months postpartum. Intake of energy and selected nutrients was tabulated and compared with dietary standards.Subjects The 52 lactating women enrolled in the study lived in a university community, were apparently healthy, had a body mass index within normal range, were successfully nursing a term infant, and planned to nurse for at least 6 months.Statistical analyses performed Paired t tests and Stuart-Maxwell χ 2 analysesResults Mean energy intakes were below the Recommended Dietary Allowance. Mean intakes of most nutrients met or exceeded recommended standards except for zinc and vitamins D and E at both 3 and 6 months postpartum. Calcium and folate intakes were also below standards at 6 months. Although mean iron intake exceeded the standard at both measurement times, there was a significant decline from 3 to 6 months. Relative frequencies of mothers meeting various percentages of standards differed significantly from 3 to 6 months for calcium; iron; folate; and vitamins E, D, and B-6. At 6 months, significant increases were noted in the number of women reporting calcium, folate, and vitamin B-6 intakes at less than one half of the recommended amounts.Applications/conclusions Guidance for lactating women should stress food sources of nutrients likely to be limited in their diets: calcium; zinc; folate; and vitamins E, D, and B-6. J Am Diet Assoc. 1998;98:297-302.