| Objectives:To investigate the micronutrients intakes from base diet, fortified foods and nutrient supplements of pregnant women in urban cities and poor rural areas, and to calculate the contribution rate of fortified foods to the total intakes of micronutrients of the target propulation. For urban pregnant women, the results will focus on the risk of excessive intakes of micronutrients, and for poor rural pregnant women, the result will concern the improving effects of fortified foods. Simulated fortification of milk powder and wheat flour were made, using different levels, to know the effective fortified content of nutrients for this population, and to give suggestion for the modification of national fortifying standard.Methods:Based on the China National Nutrition and Health Surveillance, considering the differences of dietary patterns and geographical location,3 big cities(Nanning, Hefei, Beijing) and 5 poor rural areas (Rong’an, Zhaoping, Lixin, Binhai and Wuqiang) were chosen. Questionnaire surveys were conducted in the second trimester pregnant women who went to the lacal maternal and child health hospitals, central hospitals, township hospitals to undergo prenatal examination. The base diet was recorded by 2 consecutive 24-hour weighing and recalls, the fortified foods and nutrient supplements were recorded by food frequency questionnaires in the past week and past month respectively. The mean daily intakes of some micronutrients (vitamin A, vitamin C, vitamin E, calcium, iron, zinc) of these subjects from different ways were calculated and analyzed, the contribution rate of fortified foods to the total nutrients intakes and to the RNI/AI, UL values were also evaluated.In order to test and find more effective limits of above nutrients in the national fortified standard, a simulated fortification of milk powder and wheat flour in deferent levels was made in this study, based on the lower limit and upper limit of vitamin A,calcium, ironand zinc in GB 14880-2012. The possible improving effect of products based on the new "national food safety standards, nutritional supplement food for pregnant women and lactating women" were also calculated and discussed. The basic information between urban and poor rural pregnant women was compared and the influence factors of choosing fortified foods were also analyzed in this study.Results:In this study,835 valid questionnaires were obtained, which included 298 from big cities and 537 from poor rural areas. The main results are showed as follows:1. Pregnant women from big cities were generally had proper intakes of the above 6 micronutrients, the P50 intakes of this group had reached the corresponding RNIs, but the percentage of calcium intake which was lower than RNI was high. In some subjects, the total intakes of iron and vitamin A were exceeded the Chinese UL; the intakes of these 6 micronutrients in 5 poor rural areas was relatively low, only the intakes of vitamin E, iron and zinc reached RNI, high percentage of people had a low intakes of calcium, iron and vitamin A, compared with the corresponding RNI values;2. The intakes of calcium, vitamin A and vitamin C was relatively higher from fortified foods, giving a larger proportion for the total intakes and RNI/AI, however relatively smaller for zinc, iron and vitamin E. The average contribution rate of fortified foods to the total intakes of micronutrients among pregnant women was 10.82 percent, the rate larger than 30 percent was very rare.3. The consumption rate of fortified foods in city pregnant women was 52.01 percent, only 8 cases of the subjects had a higher calcium intake, exceeding UL value, and in 5 cases, the iron intake was higher than UL. Based on the fortified level in the current national standard, the risk of excessive intakes of micronutrients caused by fortified foods was very low, if the intakes of nutrients supplements were stable.4. The fortified foods consumption rate of poor rural pregnant women was 41.34 percent.The difference of the P50 of 6 micronutrients intakes before and after fortified foods inclueded was statistically significant (P<0.05), the percentile and distribution of the intakes were significantly improved after fortified foods included.5. After simulated fortification, the intakes curves of vitamin A, calcium, iron, zinc in rural subjects moved right, the ratio of P50 which reached RNI was also increased, suggesting that the current or simulated lower limit were both effective as the lower limit. For higher limit, except iron, the remaining 3 micronutrients can be increased appropriately.6. After simulated supplements, the products which just meet the lower limit of the new standard can increase the intakes of micronutrients of poor rural pregnant women obviously, the P50 intakes of vitamin A, vitamin C and iron changed from less than 80%RNI to more than 100% RNI, the effects of products which meet the median index would be more clear and appropriate.7. The differences in awareness rate of fortified foods, concerned factors, buying inclination was statistically significant (P<0.05) between urban and rural subjects, the using rate of nutrient supplements in urban pregnant women was nearly twice of that in rural areas.The influence factors of pregnant women whom chose to eat fortified foods or not mainly contain:average monthly expenses on foods, awareness rate and occupation, and among them, 1000-2000 Yuan monthly expenses on food and known fortified foods was the positive factors, while farmer was the negative factor.Conclusions:The average contribution rate of fortified foods to the total intakes of micronutrients among of urban and poor rural pregnant women is 10.82 percent. The rate of people choosing fortified foods was not very high; therefore, on the premise of the stable use of nutrients supplements and on the basis of fortified level in the current standard, the risk of excessive intakes of micronutrients caused by fortified foods is very low. Fortified foods can be chose as an effective methods to improve the micronutrients intakes, and strengthen the publicity of science popularization of fortified foods in rural areas is recommended. The usage amount of food fortifier in GB 14880-2012 is scientific and reasonable; the fortified level of certain micronutrients has further up-regulation space through preliminary assessment. |
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