Prevalence and predictors of deficient dietary calcium intake during the third trimester of pregnancy: the experience of a developing country

Abstract

Aim: To assess the prevalence and predictors of dietary calcium deficiency in the third trimester of pregnancy.

Methods: Using an analytic cross-sectional research design we assessed antenatal out-patient clinics with a total of 503 pregnant women in the third trimester with parity less than 5, aged from 18-45 years, whether primi- or multigravida, and free from medical and gynecological diseases. Patients were screened for dietary calcium deficiency using an interview questionnaire, a food survey questionnaire and a record form for lab tests and investigations to determine the average amount of dietary calcium intake supported by normal levels of total serum calcium.

Results: About two thirds of the women assessed (66.0%) were deficient in dietary calcium. The mean daily dietary intake of calcium was 879.1 mg/day. Fifty-seven point seven percent of the women had total serum calcium levels less than 9 mg/dL, while 76.8% had levels less than 10 mg/dL. Mean total serum calcium was 8.9 mg/dL. Women with deficient dietary calcium had a lower level of education, larger family size and were more likely to be rural (P < 0.001). More underweight women were seen in the deficiency group (2.4%), and more obese women in the sufficient group (19.9%). As regards the association between dietary and total serum calcium, the regression analysis showed no correlation among the values.

Conclusions: Calcium intake in the sample studied was low. Independent predictors of dietary calcium were age (negative predictor), urban residence (positive indicator) and body mass index (BMI; positive predictor). As for the level of total serum calcium, dietary calcium and gravidity were the only statistically significant independent predictors, with gravidity being a negative predictor.