Iron status and dietary intake of Chinese pregnant women with anaemia in the third trimester

Anaemia in pregnancy is a major public health problem in China. Anaemia in pregnant women may be related to dietary intake of nutrients. To examine the relationship between iron status and dietary nutrients, a cross-sectional study in pregnant women was carried out. The intake of foods and food ingredients were surveyed by using 24-h dietary recall. Blood haemoglobin, haematocrit, serum iron, serum ferritin, transferrin and soluble transferrin receptor were measured in 1189 clinically normal pregnant women in the third trimester of pregnancy. The results showed that the average daily intake of rice and wheat was 504.2 g in the anaemia group and 468.6 g in the normal group. Carbohydrates accounted for 63.69% and 63.09% of energy in the anaemia and normal groups, respectively. Intake of fat was very low; 18.38% of energy in anaemia group and 19.23% of energy in normal group. Soybean intake was 109.4 g/day and 63.6 g/day in the anaemia and normal groups, respectively (P < 0.001). There were lower intakes of green vegetables (172.1 g/day) and fruits (154.9 g/day) in the anaemia group than in the normal group (246.2 g/day green vegetables (P < 0.001) and 196.4 g/day fruit (P < 0.001)). Intakes of retinol and ascorbic acid were much lower in the anaemia than in the normal group (P < 0.001). In the anaemia group, vitamin A intake was only 54.76% of the Chinese recommended daily allowance (RDA) and ascorbic acid intake was 53.35% of the Chinese RDA. Intake of total vitamin E was 14.55 mg/day in the anaemia group compared with 17.35 mg/day in the normal group (P < 0.016). Moreover, intake of iron in pregnant women with anaemia was slightly lower than that in the normal group. Comparison of iron status between the anaemia and normal groups found serum iron in women with anaemia at 0.89 mug/L, which was significantly lower than 1.09 mug/L in the normal group (P < 0.001). There were lower average values of ferritin (14.70 mug/L) and transferrin (3.34 g/L) in the anaemia group than in the normal group (20.40 mug/L ferritin (P < 0.001) and 3.44 g/L transferrin (P < 0.001)). Soluble transferrin receptor was significantly higher (32.90 nmol/L) in the anaemia than in the normal group (23.58 nmol/L; P < 0.001). The results of this study indicate that anaemia might be attributed to a low iron intake, a low intake of enhancers of iron absorption and a high intake of inhibitors of iron absorption from a traditional Chinese diet rich in grains.