Inadequate Intake of Calcium and Dairy Products Among Pregnant Women in Ahwaz City, Iran

Inadequate calcium intake is considered a public health problem in some vulnerable groups, especially pregnant women. The aim of this study was to determine the pattern of dietary calcium intake among urban pregnant women in Ahwaz City in south west Iran. Participants comprised 339 pregnant women (26±5.5 yrs) in the 28th-32nd week of gestation, who had attended selected urban health centres in Ahwaz City in 2004. Dietary calcium intake was estimated using a 43-item food frequency questionnaire (FFQ). Calcium intakes equivalent to, or more than, 1000 mg/d were considered as "adequate". Mean (±SD) daily intakes of dietary calcium and dairy products were 644±255 mg and 1.3±0.7 servings per day, respectively. On average, dairy products provided 49% of dietary calcium. About 43% of participants were consuming =1 serving of dairy products per day; and 89% of them did not meet adequate intake of calcium. A high proportion of pregnant women in Ahwaz City did not take enough calcium and dairy products. It is suggested that the consumption of enough calcium and dairy products should be emphasised in the nutrition education component of maternal health programmes. Further research at the country level should be undertaken in order to assess the need for fortification of food with calcium and/or to provide calcium supplements to vulnerable groups. ____________________ Correspondence author: Majid Karandish, email: [email protected] effects, including weight and body fat regulation and prevention of some chronic diseases have been suggested for calcium (FAO & WHO, 2002; Weaver & Heaney, 1999; Heaney, Davies & Barger-Lux, 2002; Miller & Anderson, 1999). The negative effects of inadequate calcium consumption on maternal and foetal bone health and development (Ortega et al., 1998; Chang et al., 2003), and the positive effects of maternal supplementation with calcium on the blood pressure of the offspring have also been proposed (Belizan et al., 1997; Bergel & Belizan, 2002). Most of the calcium is transferred to the foetus during the third trimester of pregnancy (about 200 mg/d) (FAO & WHO, 2002). The importance of adequate calcium intake has led to recommendations to include calcium-rich foods/supplements into dietary guidelines (Heaney, 2000). In addition, calcium supplementation was recommended for pregnant women who take =1 serving of calcium-rich food products daily (IOM, 1990). While available evidence has suggested that a high proportion of Iranian population does not consume enough calcium (Salimi, Djazayeri & Nikkhuy, 2000; NNFTRI, 2004, Houshiar-rad et al., 1998), data on dietary calcium intake among pregnant women in different parts of the country is lacking. Hence, the aim of this study was to determine the adequacy of calcium intake among urban pregnant women in Ahwaz, south west Iran. SUBJECTS AND METHODS Participants were 339 healthy pregnant women, with gestational age between 28 and 32 weeks, 18-35 yrs of age (mean of 26 yrs), singleton pregnancy, who were not taking supplements other than iron and folate. In Ahwaz City, there were 22 “mother and child clinics”. As a first step, eight clinics were selected randomly and then the calculated number of participants was recruited sequentially among women who fulfilled the inclusion criteria. Data collection was carried out in 2004. Since the clinics were selected randomly from all districts of the City, it is very probable that the participants were from all socioeconomic segments of the community. Informed written consents were obtained from all participants. A pre-tested questionnaire (Karandish, Djazayeri & Mahmoodi, 2003) was used to collect data. The first part of the questionnaire was allocated to general socio-demographic and health characteristics. Socio-demographic information was obtained from the “Family Health File” available at the health centers. The language used in the questionnaire was the formal national language of Iran, namely Farsi, which all the participants could understand. Trained interviewers administered the questionnaire by a face-to-face interview at the clinics. Anthropometric measurements including weight and height were carried out according to the World Health Organization protocols (WHO, 1995). Prepregnancy weight was obtained from health records. Body Mass Index (BMI) value was calculated using the equation Wt (kg)/Ht(m)2. The reported BMI was pre-pregnancy BMI. A 43-item semi-quantitative food frequency questionnaire (FFQ) was used to estimate individual calcium intake. A complete sample of the FFQ used is shown in Table 1. The participants were asked about their consumption frequency within the last 6 months prior to the study. All common food sources of calcium were included in the FFQ. In order to estimate the amount of usual calcium intake during pregnancy, the fractional portion size of each food consumed per day was multiplied by its calcium content, obtained from the national food composition table (NNFTRI, 1979). The values were then summed up to obtain an estimate of an individual's total daily calcium intake. The 112 Karandish M et al. Intake of calcium and dairy products among pregnant women 113 Table 1. Semi-quantitative food frequency questionnaire used to estimate calcium intake in pregnant women in Ahwaz City, Iran (n=339) Food Portion size Never <1/w 1-2/w 3-4/w 5-6/w Daily 2/d 3/d >3/d Bread Rice Pasta, macaroni Milk Cheese Yoghurt Ice crea Kashk a Cocoa milk Dough b Sardine fish Tuna conserve Other fish Sausages Red meat Poultry Pizza Soya Spinach Green veg. (raw) Salad vegetables (cucumber,.) Green veg. (cooked) Cabbage, cauliflower (raw) Cabbage, cauliflower (cooked) Okra Beans and legumes Almond Sun flower seed Other nuts Egg (boiled or fried) Egg in foods Biscuit and cake Lime Fruits Fruit juices Date Spices Potato Chocolate Cocoa Cola drink Coffee Tea aLocal dairy product, which is produced from dried whey. bLocal dairy drink, which is produced from yoghurt diluted by water 1 slice 1⁄2 cup 1⁄2 cup 1 cup 1.5 match box 3/4 cup 1⁄2 cup 1 table spoon 1 cup 1 cup 70 g 100 g 2 ounces 2 small 2 ounces 2 ounces 1 medium slice 1⁄2 cup 1⁄2 cup 1 small dish 1 medium portion 1⁄2 cup 1⁄2 cup 1⁄2 cup 1⁄2 cup 1⁄2 cup 30 g 30 g 30 g 1 medium 1 medium 1 medium 1 medium 1 medium serving 1 cup 4, dried g 1 medium 50 g g 1 cup 1 cup 1 cup latest Dietary Reference Intake (DRI) of calcium for adult pregnant women, i.e. 1000 mg/d as Adequate Intake (AI) according to the Food and Nutrition Board, Institute of Medicine, was considered as the recommended amount for pregnant women (IOM, 1997). Based on daily consumption of dairy products, subjects were divided into 2 groups of “Low Dairy” and “High Dairy” (<1 and >1 serving/d, respectively) (IOM, 1990). Correlations between intake of dairy products (as number of servings) and attainment of calcium intake were determined by χ2 test. Linear regression model was employed to analyse associations between the calcium proportion of dairy products or intake of dairy products (as number of servings) and total calcium intake. P value less than 0.05 was considered as statistically significant. All statistical analyses were carried out using the Statistical Package for Social Science (SPSS, version 9.0). The study protocol was approved by the “University Research Council” as well as “The Ethics Committee”, Ahwaz JondiShapour University of Medical Sciences and Health Services, Iran.