Are Prenatal Vitamins Essential?

When the National Academy of Sciences recommended, in a report published last week, that pregnant women avoid multivitamin supplements and instead get the extra nutrients they need from a balanced diet, it came as a great surprise to many women.

Some said they would agree to consult with their physicians but believed supplements were necessary as insurance. Others said they would outright refuse to heed the advice, which they viewed as “ridiculous.”

“I take a prenatal vitamin, plus extra calcium and iron supplements,” said Aimee Oswald, a medical receptionist whose baby is due in November, “because sometimes you can’t eat all the right foods. When you’re sick you have to eat what looks good to you. . .sometimes I have a hard time just getting crackers down. I refuse to give mine (vitamins) up. I need them.”

This reaction to the recommendations of the 11-member panel of medical and nutrition experts and an auxiliary committee of specialists is not unusual. Since obstetricians commonly prescribe prenatal vitamins to expectant mothers to ensure nutritional adequacy, many people believe the pills are essential for delivery of a healthy baby.

Some research has even shown that those women who take multivitamin supplements containing folic acid around the time of conception have a reduced chance of having a baby with a defect of the spinal cord, such as spina bifida.

This birth defect, also called a neural tube defect, occurs when the neural tube, a pre-embryonic structure that develops into the spine and the brain during the third and fourth week of pregnancy, fails to close completely.

It effects an estimated 2,500 to 3,000 newborns each year. And although there is no known exact cause, experts believe the mother’s nutritional status and other environmental factors may interact with her genetic predisposition and increase risk for the defect.

But lacking sufficient evidence of a direct link, the government committee concluded that, “there is not enough evidence to recommend a folic acid supplement to all women of child-bearing age.”

It is known that folic acid has a role in development of red blood cells and genetic material in body cells. Anemia can even result when folic acid intake is inadequate. During pregnancy the requirement for folic acid (also known as folate and folacin) does increase, but the question of supplementation to reduce risk for birth defects is “quite a different issue,” according to the chairman of the government committee.

“In the ordinary clinical sense the neural tube defect has occured almost by the time that a woman is aware that she is pregnant,” said Dr. Roy Pitkin, department of obstetrics and gynecology at the UCLA School of Medicine, who chaired the committee. “If she waits until she knows (she is pregnant) to institute vitamin therapy--even if it is effective--then it will be too late. All of these studies that have examined (the connection) have involved women who were already taking multivitamins before conception.”

The panel did, however, call for studies to determine a relationship between multivitamin supplements and birth defects. The Spina Bifida Assn. of America last week also made this recommendation.

Until all the data is in, the committee said that careful menu planning can help achieve achieve adequate nourishment for mother and fetus through diet. Food is the preferred source of folic acid and many other nutrients--except iron--the committee said because most women typically fail to meet the Recommended Dietary Allowance through diet. A low-dose ferrous iron supplement of 30 milligrams is suggested.

Women of child-bearing age are encouraged to eat “adequate” amounts of fruits, vegetables, whole grains and legumes--all good sources of folate. A new U.S. Department of Agriculture publication can explain just how much is “adequate.”

“Good Sources of Nutrients,” lists the top sources of 16 vitamins and minerals and dietary fiber--and both folic acid and iron are among them. It also gives information on how to prepare and store foods to avoid nutrient loss, explains serving sizes and tells why each vitamin or mineral is important.

“This information will help consumers select a variety of foods that provide the vitamins, minerals and fiber they need,” said Sue Ann Ritchko, administrator of the USDA’s Human Nutrition Information Service.

Since folic acid is a water-soluble vitamin, it is easily destroyed during preparation, cooking and storage, so fruits and vegetables should be served raw whenever possible. Or, they can be steamed, boiled or simmered in a minimal amount of liquid. Store vegetables in the refrigerator.

Here are some good sources of folic acid according to the USDA. Raw forms of some vegetables are not included, because in their raw state they don’t contain enough folic acid. For example, a 1/2-cup cooked serving of beets contains more than the same amount of the vegetable raw.

Also, the term “good source” is based on the RDA of 400 micrograms daily for a pregnant woman. Desirable intakes for women, men and children, which are less, would be about half.

The following foods supply 40% of the RDA: three ounces braised beef or calf liver, 1/2 cup cooked black-eyed peas or 1/2 cup cooked lentils.

The following foods supply 25 to 29% of the RDA: one ounce fortified ready-to-eat cereal--depending upon the brand (check the label), 1/2 cup cooked spinach, three ounces pork or 1/2 cup cooked red kidney beans.

The following foods supply 10 to 24% of the RDA: one whole-wheat English muffin; one small whole-wheat pita-bread round; two tablespoons plain wheat germ; 3/4 cup grapefruit and orange juice frozen, reconstituted; 3/4 cup fresh or frozen reconstituted orange juice; one medium artichoke cooked; 1/2 cup cooked asparagus, beets, broccoli, Brussels sprouts, cauliflower, Chinese cabbage, cream-style corn, mustard greens, okra, parsnips, green peas, spinach or turnip greens; one cup raw endive, chicory, escarole, romaine or spinach; three ounces steamed crab meat; 1/2 cup cooked bayo, black, brown, calico, garbanzo, lima, Mexican, pinto, white beans or split yellow or green peas.

The USDA package also includes fact sheets on Vitamins A, E, C, B-6, B-12, thiamine, riboflavin, niacin, calcium, iron, magnesium, copper, zinc, phosphorous, potassium and dietary fiber.

“Good Sources of Nutrients” may be obtained by writing to: Consumer Information Center, Pueblo Colo. 81009. When ordering, include the item number 171W and a check or money order for $5 payable to the “Superintendent of Documents.”