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

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.