BACKGROUND/OBJECTIVES: Postpartum bone metabolism undergoes substantial alterations based on breastfeeding status. Research on maternal calcium intake and bone recovery, particularly among Asian women, remains limited. This study investigated postpartum change in bone mineral density (BMD) and its association with calcium intake during late pregnancy and post-delivery according to breastfeeding status. SUBJECTS/METHODS: Thirty-six women (22 breastfeeding, 14 non-breastfeeding) underwent dual-energy X-ray absorptiometry 3 times: 1) within 3 days of delivery, 2) at 6 mon postpartum for non-breastfeeding women or within 1 mon of weaning for breastfeeding women, and 3) at 12 mon postpartum. Dietary calcium intake was evaluated using a food frequency questionnaire and dietary supplement survey at all visits. Association between calcium intake with percentage change in BMD (%ΔBMD) was assessed by linear regression. RESULTS: The BMD at the lumbar spine, total hip, femoral neck, and trochanter significantly decreased during breastfeeding, whereas non-breastfeeding women displayed increased BMD at the femoral neck at 6 mon postpartum. In non-breastfeeding women, postpartum calcium intake was positively associated with %ΔBMD at the total hip, femoral neck, and intertrochanter (P < 0.05). Few significant associations were observed between %ΔBMD and late pregnancy intakes across all women, regardless of breastfeeding status. At 12 mon, BMD in breastfeeding women recovered to delivery levels, while non-breastfeeding women maintained their BMD observed at 6 mon postpartum. CONCLUSION Postpartum calcium intake is positively associated with bone recovery in non-breastfeeding women, suggesting that its effects on bone recovery potentially vary with lactation status.

Objectives: Nutrient intake during pregnancy and lactation is crucial for the health of both mother and offspring. Diet and nutrient metabolism potentially vary according to ethnicity and fetal number; nevertheless, recent studies validating this are inadequate. Furthermore, few studies have tracked changes in intake after delivery. We compared the food and nutrient intakes between pregnant women in Korea carrying singletons and multiples during late pregnancy and assessed their changes through postpartum. Methods: Ninety-eight pregnant women were recruited from Chonnam National University Hospital between January 2019 and December 2023, and 48 responded to follow-up. Third trimester and postpartum intake were assessed via food frequency questionnaires and supplement questionnaires. Student’s t-test, Mann–Whitney U test, chi-square test, paired t-test or Wilcoxon signed-rank test was performed and adjustments were made for covariates. Results: Nutrient intake was generally adequate relative to the Dietary Reference Intakes for Koreans, with no differences between singleton- and multiple-pregnancy women. Sixty-six of 98 (67%) pregnant women consumed meat, fish, vegetables, and fruit daily. Dairy intake was low, while the mean iron intake during pregnancy reached 54.2 ± 34.0 mg/d, exceeding the tolerable upper intake level, mainly owing to supplements. Postpartum fruit and vitamin C intake decreased, with no significant differences between breastfeeding and non-breastfeeding women. Conclusion Dietary intake did not significantly differ between Korean singleton- and multiple-pregnancy women. Dairy intake was low and iron intake was excessive. Fruit intake decreased after delivery; however, difference in dietary intake according to breastfeeding status was minimal. Nutritional education may be necessary to promote a balanced diet in pregnant and postpartum women. Trial Registration: Clinical Research Information Service Identifier KCT0005118.