Background: With respect to important role of nutrient and calcium intake in the health of fetus, newborn and mother, the current study carried out to determine nutrient intake and biochemical serum factors related to calcium metabolism during normal pregnancy in Tehranian women.

Materials & Methods: In a cross sectional study, 101 normal pregnant women from 5 prenatal care centers and 94 non-pregnant women randomly selected from the Tehran Lipid and Glucose Study population were enrolled. A questionnaire was used to obtain demographic data, 2-day dietary recall and food habits during face-to-face interviews. Venous blood samples were taken to measure serum calcium, magnesium, phosphorus and 25-OH vitamin D. Data were adjusted for age, BMI and weight in both case and control groups. Nutrition intakes were analyzed using Nutritionist III software and compared to DRI recommendations. T-test was used for statistical analysis.

Results: Mean daily magnesium, calcium phosphorus and vitamin D intakes were 183±79, 859±388 and 1009±398 mg and 0.39±0.34 μ cg, respectively. Mean magnesium, calcium, phosphorus and vitamin D intakes were significantly decreased during pregnancy as compared to recommended daily intakes: 86, 47.7, 7.5 and 100% of DRI, respectively, (magnesium, phosphorus and vitamin D, P<0/001 and calcium, P<0/01). Pregnant women had higher nutrient intakes than non-pregnant ones of magnesium, calcium, and phosphorus (P<0.001). There were no differences in vitamin D intakes between the two groups. Mean serum levels of calcium, phosphorus and vitamin D were 9.1±0.6, 4.0±0.6 mg/dl and 24.3±14.1 ng/m respectively, not significantly different from the controls. Significant differences were found in the mean serum levels of magnesium in pregnant women with their controls (P<0/01).

Conclusion: Daily intakes of vitamin D, magnesium, calcium and phosphorus and serum vitamin D levels are low in pregnant women of Tehran. Findings emphasize the need for nutritional counseling programs for these women.