Effects of Nutrient and Food Intake on Calcaneous Bone Mass among Healthy Japanese Women in the Predelivery and Postpartum Periods

Abstract

Objective:

To clarify the dietary factors affecting change in calcaneous bone mass during the predelivery and postpartum periods in healthy Japanese women.

Methods:

The calcaneous bone mass was measured as the osteo sono-assessment index (OSI) using the quantitative ultrasound method in 76 Japanese women who were pregnant between February and June 2000. These women subsequently experienced normal pregnancy and labor and could be followed until the sixth month after delivery at an obstetrics and gynecology clinic center located in metropolitan Tokyo. After the intraindividual changes in the OSI during the follow-up period were determined, the relationship between the OSI or OSI change from gestation to the postpartum period and the estimates of nutrient and food intake obtained using a 140-item semiquantitative food frequency questionnaire (FFQ) were analyzed using stepwise multiple regression analysis.

Results:

Iron intake in gestation was a significant positive correlate with the percentage change in the OSI between week 36 of gestation and day 5 after delivery (p < 0.001) and that between week 36 of gestation and month 6 after delivery (p < 0.001) (partial regression coefficient of energy-adjusted iron intake, β = 0.493 mg/day and 0.342 mg/day, respectively). Intake of vitamin D and fruits and vegetables during gestation and/or postpartum was positively associated with the OSI change from week 36 of gestation to the postdelivery stage, whereas the OSI change was inversely related to the intake of carotene, sodium chloride, and meat in the gestation or postpartum period.

Conclusions:

Sufficient intake of iron, vitamin D, or fruits and vegetables may be important for the preservation of bone mass after delivery.