[Evaluation of calcium intake levels and sources among pregnant women in a Chengdu hospital in 2017].

Objective: Investigate and evaluate the levels and sources of calcium intake of pregnant women in Chengdu during three trimesters.

Methods: Use the data of a cohort study in Chengdu in 2017. The healthy singleton pregnant women with 8-14 weeks of pregnancy in an obstetrical clinic of a maternal-and-child health care institution in Chengdu were selected as the object of the study. Data on maternal demographic characteristics and the use information of calcium supplements in the past month of each trimester were collected by questionnaire investigation. The dietary intakes data of pregnant women in each trimester was collected by the 3-day 24-hour dietary recall method. The dietary calcium intake and the contribution of calcium from different foods were calculated based on the Chinese Food Composition Table(2018). The total calcium intake was obtained by adding the dietary calcium and supplement calcium intake. The calcium intake was evaluated with reference to the Chinese Dietary Nutrient Reference Intakes(2013).

Results: Valid samples of 1653 cases in early pregnancy, 1024 cases in middle pregnancy and 1017 cases in late pregnancy were finally included. The median intake of total calcium was 523.3, 1280.5 and 1491.3 mg/d in three trimesters, respectively. The adequate rate of total calcium intake was 16.3%, 63.2% and 67.1%, the insufficient rate was 69.0%, 15.7% and 11.2%, the excess rate was 0.2%, 9.1% and 14.4%, respectively. The median intake of dietary calcium was 453.0, 613.0 and 723.0 mg/d in three trimesters respectively. The dietary calcium adequate rates were 7.1%, 9.7% and 16.2%, the dietary calcium deficiency rates were 82.0%, 75.0%, 62.6%, respectively. The main food sources of dietary calcium in each pregnancy were dairy foods, vegetables, tubers and grains. The contribution of dairy foods to the dietary calcium was 33.8%, 37.7% and 40.2%, respectively. The median intake of milk was 125.0, 235.3 and 250.0 g/d, respectively. Among all pregnant women, the calcium supplement use in three trimesters was 36.2%, 93.4% and 91.7%, respectively; the median intake of supplement calcium was 0.0, 625.0 and 750.0 mg/d, respectively. Among pregnant women who met the dietary calcium standard, the use of calcium supplements in the three trimesters was 38.1%, 95.0% and 94.5%, respectively; the median intake of supplemental calcium was 0.0, 725.0 and 750.0 mg/d, respectively.

Conclusion: The insufficient and excessive total calcium intake coexisted among pregnant women in Chengdu, with the insufficient dietary calcium intake prominent in all trimesters. The use of calcium supplements was common in middle and late pregnancy.