Vitamin Supplements For Pregnant Women Articles & Resources

The Healthy Eating Index (HEI) was developed by the US Department of Agriculture (USDA) "to provide a single summary of diet quality based on different aspects of a healthy diet." This tool was developed to measure how well the diet adhered to the recommendations of the Dietary Guidelines for Americans and to assess diet quality using a single composite number. A maximum score in this index is 100, with a score of 80 or above indicating a good diet. The USDA has used the HEI to assess diet quality in the general US population over time. The HEI has also been used to assess the association of diet quality with risk factors for chronic disease. The USDA HEI is based on foods rather than nutrients, and was designed to measure diet quality as compared with US national guidelines. For pregnant women, the goals are to prevent low birth weight and birth defects and to support maternal nutrition without excessive weight gain. Inadequate intakes of micronutrients are associated with poor pregnancy outcomes. It is unknown whether the HEI is an adequate measure of diet quality in pregnancy.

Because the HEI might be a useful tool for describing the overall quality of the diet in pregnant women, this pilot study was conducted to examine the diets of a group of women of childbearing age (18 to 40 years): healthy young women and pregnant women between 20 and 38 weeks' gestation. From the diet study, a detailed cross-sectional assessment of the dietary practices of this age group of women and an overall composite index of their diets were obtained. The HEI was applied to the diets of pregnant women to measure how well their diets compared with Food Guide Pyramid guidelines and, considering special needs in pregnancy, explored whether the current USDA HEI meets the needs for an HEI for pregnancy.

Of the 112 nonpregnant and pregnant women who responded, 101 women completed the study. The main reason for nonparticipation was that they were "too busy." A registered dietitian verbally instructed each participant individually and provided written instructions on how to record details of everything she ate at home and elsewhere for 4 consecutive days, including 1 weekend day. Items were recorded using household measures. For all women, body weight was measured using a balance beam scale, and height was measured using a stadiometer. The diet of each subject was assessed using the USDA HEI. The HEI for pregnant women was calculated using the published recommended number of Food Guide Pyramid servings for pregnant women. The HEI evaluates the overall quality of the diet through the identification of 10 components: five Food Guide Pyramid food groups [grains, vegetables, fruits, milk, and meat, expressed as servings/day], total fat intake, saturated fat, cholesterol, sodium, and variety. The overall index has a possible perfect score of 100. Each of the 10 dietary components has a scoring range of 0 to 10. For the food groups, individuals with an intake at the recommended level receive a perfect score of 10, and a score of 0 is given if no foods from a group are eaten. Intermediate scores are calculated proportionately.

Forty-nine healthy control women and 52 healthy pregnant women at [+ or -] weeks' gestation took part in the study. Vitamin supplements were used by 41% of the control and 79% of the pregnant group. The mean dietary fiber intakes of 23 [+ or -] g/day for the pregnant group and 20 [+ or -] g/ day for the nonpregnant group were below the recommended adequate intake of 25 g/day for nonpregnant women and 28 g/day for pregnant women. Daily calcium intake for the pregnant group (1,139 [+ or -] mg) met recommendations, whereas the nonpregnant group intake of 897 [+ or -] mg/day fell short of the recommended adequate calcium intake of 1,000 g/day. The diets of pregnant women met the recommended adequate daily intake of micrograms/day for vitamin D, whereas those of nonpregnant women did not. Iron intake was similar in both groups; [+ or -] mg/day for the pregnant and [+ or -] mg/day for the nonpregnant group, but was below the recommended daily intake of 27 mg/day and 18 mg/day, respectively. The daily folate intake for the control group of 300 [+ or -] micrograms/day and for the pregnant group of 331 [+ or -] micrograms/day was considerably less than the recommendation of 400 micrograms/day and 600 micrograms/day, respectively. Nearly all (98%) of the pregnant women and most of the control women (80%) did not meet the minimum daily recommended intake for folate.

When intake of nutrients of concern was examined in those subjects with a good HEI (>80), it was found that in nonpregnant subjects only 33% and 25% met recommendations for iron and folate, respectively, through food intake. In the pregnant group, only 4% of subjects met folate recommendations and none met iron recommendations through food intake alone. The USDA HEI, in pregnant and nonpregnant women, seems to provide a useful tool for comparing the diets against the Food Guide Pyramid, but the detailed analysis of micronutrients of concern in pregnancy shows that the HEI does not discern the need for vitamin and mineral supplements during pregnancy.

The researchers conclude that the existing USDA HEI showed how well the women followed the food guidelines, but in pregnancy, it failed to pick up micronutrient deficiencies. A new HEI for pregnancy would measure diet quality in pregnancy in relation to goals, and would need to factor in a way to assess micronutrients of special concern in pregnancy. Because outcomes of pregnancy vary depending on the mother's prepregnancy nutritional status, it is also important to examine dietary needs in young women of childbearing age. A new HEI for pregnancy could be applied to this group of women as well because the needs are very similar. For nonpregnant women, the USDA already has carried the HEI one step further and has created the Interactive Healthy Eating Index on the Internet, at .gov/cnpp. A careful 1- to 3-day food record obtained by a dietetics professional can be readily used to quickly calculate an HEI using the Web site. In the future, an interactive HEI for pregnancy would allow pregnant women to assess their own diets and would give them information to make appropriate changes as required.

M Pick, M Edwards, D Moreau, E Ryan. Assessment of diet quality in pregnant women using the Healthy Eating Index. JADA 105(2):240-246 (February 2005) [Correspondence: Edmond A. Ryan, MD, 362 Heritage Medical Research Building, Edmonton, Alberta T6G 2S2, Canada. Email: ]