How to get all the critical nutrients you need for a healthy baby
Never before have your food choices mattered so much. From conception to delivery, or longer if you breastfeed, your baby is dependent on nutrients from you for the growth and development of all his cells, tissues and organs. Every bite of food you take (or don’t take) counts.
Fortunately, providing you and your baby with the best mix of nutrients is a simple matter of eating lots of fresh fruits and vegetables, whole grains, legumes and low-fat milk products along with a little extra-lean meat, chicken or fish. In addition, research recently has uncovered a few other links between diet and your baby that you should consider.
Folic Acid to the Rescue New findings about the B vitamin folic acid seem to be making the news daily. You’ve probably heard by now that folic acid intake before and during the early months of pregnancy is essential for preventing neural tube defects, but it might be just as important in the third trimester, say researchers at the University of Medicine and Dentistry of New Jersey. When average folic acid intakes and blood levels in pregnant women were measured and related to the outcomes of their pregnancies, researchers found that those women with low average daily folic acid consumption (i.e., less than 240 micrograms a day) and/or low blood folic acid levels at 28 weeks of pregnancy had twice the incidence of preterm delivery and low-birth-weight babies as those getting adequate amounts of this vitamin.
The Calorie Count
If you don’t eat enough during pregnancy, your baby is robbed of calories and nutrients, which can result in low-birth-weight or premature infants who are more prone to health problems. This doesn’t mean you can eat all you want (see “Weight Gains: What’s Safe?” page 52). Your daily energy needs during the first trimester are the same as they were before pregnancy (approximately 2,200 calories), and they increase by only 100 to 300 calories during the second and third trimesters, for a daily total of 2,300 to 2,500 calories.
An average-weight woman should gain about 25 to 35 pounds during her pregnancy. Women who are overweight should gain no more than 15 to 25 pounds, while underweight women should gain approximately 28 to 40 pounds, depending on their height and degree of leanness prior to pregnancy.
It’s not just total weight gain, but the pattern of weight gain that’s important. In the first trimester, you should experience a slow gain of about 2 to 5 pounds total (more if you’re thin, very active or tall; less if you’re overweight, sedentary or short). In the last two trimesters, your weight should steadily increase by approximately 3/4 to 1 pound a week.
Prior to and early in pregnancy, less than one milligram of folic acid consumed each day could be all it takes to prevent neural tube defects (NTD), a congenital abnormality (see “What Are Neural Tube Defects?” page 80). Andrew Czeizel, M.D., director of the Department of Human Genetics and Teratology at the National Institute of Hygiene in Budapest, Hungary, reports that folic acid supplements taken at least one month before and for the first few months of pregnancy reduce the risk for NTDs.
Czeizel’s research and other studies on the importance of folic acid have prompted the U.S. Public Health Service to recommend that all women of child-bearing age capable of becoming pregnant consume 400 micrograms and pregnant women, 800 micrograms of folic acid a day to reduce the risk of having a baby with spina bifida or other NTDs.
In fact, the link between folic acid and birth defects is so strong that the Food and Drug Administration recently announced mandatory folic acid fortification of enriched breads and cereals by January 1998. Under the fortification program, the agency is requiring manufacturers to add from 430 micrograms to 1.4 milligrams of folic acid per pound of product to enriched flour, bread, rolls, buns, farina, corn grits, cornmeal, rice and noodle products. A serving of each of these products could provide about 10 percent of the daily value (formerly called recommended daily allowance, or RDA) of folic acid for pregnant women.
However, you can’t depend solely on fortification of processed foods to meet your folic acid needs. Stick with at least two to three daily servings of the ol’ standbys, dark-green leafy vegetables, or take a supplement.
Supplement Sensibly Most experts agree that food is your best source of nutrients. Problem is, many women don’t eat enough of the right foods during pregnancy to guarantee optimal intake, according to a 1993 study of pregnant and lactating women based on a U.S. Department of Agriculture (USDA) survey. “Three out of every four women in our study didn’t consume even one serving of dark-green leafy vegetables on a given day,” reports Lori Borrud, D.P.H., R.D., of the USDA.
When women aren’t getting what they need from their food, supplements become crucial. Besides the definite advantage of folic acid supplementation, many pregnant women may need iron supplements since they are at particular risk for deficiency. Up to 7.4 percent of women in their first trimester and up to 55 percent in their third trimester are iron-deficient, which places them at risk for preterm labor, low-birth-weight babies and stillbirths, say researchers at the University of Oklahoma. Up to 60 milligrams of iron can be taken during pregnancy, but always check with your doctor before taking any supplement.
Even with all the new research on the need for extra nutrients, supplementation can still be a mixed bag. “With all of the awareness among pregnant women about what vitamins and minerals they need before and during their pregnancies, we want to make sure they don’t consume too much,” says Nancy Butte, Ph.D., associate professor of pediatrics at Baylor College of Medicine, Houston and research scientist at the USDA Children’s Nutrition Research Center, Houston. “There are people who feel that if a little of something is good, more is better. That can be dangerous.”
Too much vitamin A poses the most danger to pregnant women. Researchers at the Boston University School of Medicine found that even moderate doses of this vitamin can cause birth defects. Women in this study who consumed 10,000 IU or more of vitamin A daily were at considerably higher risk of having babies with birth defects, including cleft palate and heart defects.
Most important, the hazards were noted within the first seven weeks of pregnancy, often before a woman knows she is pregnant. This study is an exception to the rule that one study should not a conclusion make. The March of Dimes now recommends that pregnant women (and those in their childbearing years) limit their total vitamin A intake to 5,000 IU daily. A good way to get this is through beta carotene–rich vegetables, since this vitamin A precursor is relatively nontoxic at any dose.
Studies continue to show that women who eat well and supplement sensibly have the best chance of maintaining optimal nutritional status and giving birth to healthy, full-term babies. For healthy women, a prenatal vitamin and mineral that supplies 100 to 200 percent of the recommended dietary allowances for all nutrients is best. However, as mentioned above, iron and folic acid may be recommended in greater amounts.
Taking supplements, though, won’t cover all your nutritional bases. Janet King, Ph.D., R.D., director of the Western Human Nutrition Research Center, San Francisco, and professor of nutritional sciences at University of California, Berkeley, supports the use of supplements during pregnancy but cautions: “Women who assume that supplements will meet all their needs and forget to pay attention to their diets could be doing themselves more harm than good. Recent research has shown that it is especially important for pregnant women to consume five servings of fruit and vegetables daily to assure a good intake of folic acid and other vitamins. Also, there are critical elements in food, such as fiber, other nutrients and sufficient calories, which supplements can’t provide.”
Drink your (low-fat) milk Milk contains cal-cium, a mineral critical to bone formation and muscle and nerve function. While many people try to cut down on high-fat dairy products in the name of health, you’d be hard-pressed to meet your maternal calcium needs without milk products. For example, you must consume two cups of cooked broccoli, chard or kale to get the same amount of calcium as one cup of low-fat milk. You need between six and eight cups of these vegetables to meet your daily calcium needs. “Milk products also supply other essential nutrients,” says King, “such as vitamin D and vitamin B2 [essential for normal bone, muscle and nerve development], which are difficult to get anywhere else.” Consequently, nothing matches the benefits of including two to three servings of low-fat dairy foods in your diet each day.
If you need supplementation or choose to get calcium from supplements instead of food, make sure that the source is calcium carbonate or calcium citrate. “Natural” calcium sources, such as oyster shell calcium and bone meal, may contain lead and other metals potentially harmful to your baby.
New research shows that taking calcium supplements during pregnancy also decreases your chances of developing high blood pressure. In 14 clinical trials tallied by researchers at McMaster University, Ontario, Canada, supplementation—with 1,500 to 2,000 milligrams daily—cut the risk of pregnancy-induced hypertension by 62 percent.
No matter how much help you do or don’t get from your doctor, gearing up for pregnancy means doing your own nutritional homework. One place to start is by keeping a daily checklist. It’s a quick and easy way to stay on top of the daily nutritional needs for both you and your baby.