The body absorbs folic acid with twice the efficiency of food folate, which explains the recommendation for the man-made variety. Even so, folate-rich foods are important, too.

Fortified foods include:

• 1 ounce ready-to-eat breakfast cereals: 100-400 micrograms folic acid
• 1 cup cooked enriched spaghetti: 80 micrograms folic acid
• 2 slices enriched bread: 34 micrograms folic acid

Folate-filled foods include:

• 1 cup cooked lentils: 358 micrograms folate
• 1 cup cooked spinach: 263 micrograms folate
• 1 cup cooked broccoli: 168 micrograms folate
• 1 cup orange juice: 110 micrograms folate

Iron

Iron is responsible for transporting oxygen to cells and tissues throughout the body. It's important for women to consume adequate iron before pregnancy as well as during.

"Pregnancy is a drag on iron stores and may cause iron-deficiency anemia in mom," Wright says.

To avoid health problems, experts say women should include foods rich in heme-iron, the highly absorbable form found in animal foods, and include iron-rich plant foods or iron-fortified foods along with vitamin C. Vitamin C enhances the absorption of non-heme iron. The ideal amount is about 18 milligrams of iron daily for women ages 19 to 50. Pregnant women should get 27 milligrams a day.

Heme-iron sources:

• 3 ounces cooked beef: 3 milligrams
• 3 ounces cooked turkey: 2 milligrams
• 3 ounces cooked light meat chicken: 1 milligram

Non-heme iron sources:

• 3/4 cup Whole Grain Total cereal: 22 milligrams
• 1 cup fortified instant oatmeal: 10 milligrams
• 1 cup cooked soybeans: 8 milligrams
• 1 cup boiled kidney beans: 5 milligrams

Older Adults, People with Dark Skin, and Those Who Avoid the Sun

What do these groups have in common? They may lack vitamin D.

Vitamin D production is initiated in the skin in response to sunlight. People who avoid the sun may not make enough vitamin D. Ditto for people with darker complexions, who have a higher level of melanin, a natural sunscreen.

Age decreases the body's ability to make vitamin D, so older people may easily become deficient, even when they get enough sun. To make matters worse, vitamin D needs double after age 51 to 400 international units (IU) a day (the equivalent of four glasses of milk), and increase to 600 IU daily after age 70.

In addition, most foods are poor natural sources of vitamin D. That's why experts recommend consuming vitamin D from fortified foods, including milk and breakfast cereals, and from supplements. You may need a mixture of both to get the vitamin D your body requires.

Originally Published Sept. 26, 2006.
Medically Updated December 19, 2007.

SOURCES: Hillary M. Wright, MEd, RD, Boston. Marissa Moore, RD, spokeswoman, American Dietetic Association. National Institute of Medicine. United States Department of Agriculture, on-line nutrient data base, Agricultural Research Service. National Academies Press, "Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids," "Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, Fluoride," "Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline," "Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium and Carotenoids," "Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc," "Dietary Reference Intakes for Water, Potassium, Sodium and Chloride."

©2007 WebMD Inc. All rights reserved.