Women and Nutrition: Vitamins, Calcium, Iron, Calories, Weight Control, Cholesterol

by Food and Drug Administration (FDA)

Breast cancer. Osteoporosis. Iron deficiency. Weight reduction. What do these things have in common? They are either unique to women, or are more prevalent in women. And they affect current recommendations on what women should eat for optimum health.

While new information on what's good and what's bad seems to surface almost daily, some basic guidelines have taken root over the past several years.

The bottom line (also known as the Dietary Guidelines for Americans, from the Departments of Health and Human Services and Agriculture) is:

• eat a variety of foods
• maintain healthy weight
• choose a diet low in fat, saturated fat, and cholesterol
• choose a diet with plenty of vegetables, fruits, and grain products
• use sugar and salt/sodium only in moderation
• if you drink alcoholic beverages, do so in moderation.

That sounds simple enough. Except, what exactly is variety? Cake one day, cookies the next? What is a diet low in fat, saturated fat, and cholesterol? And, finally, what parts of a healthy diet have special importance for women?

Vitamins and Minerals

There are several vitamins and minerals essential to a healthy diet. A well-balanced diet will usually meet women's allowances for them. (See Recommended Dietary Allowances.) However, for good health, women need to pay special attention to two minerals, calcium and iron.

Calcium

Both women and men need enough calcium to build peak (maximum) bone mass during their early years of life. Low calcium intake appears to be one important factor in the development of osteoporosis. Women have a greater risk than men of developing osteoporosis.

A condition in which progressive loss of bone mass occurs with aging, osteoporosis causes the bones to be more susceptible to fracture. If a woman has a high level of bone mass when her skeleton matures, this may modify her risk of developing osteoporosis.

Therefore, particularly during adolescence and early adulthood, women should increase their food sources of calcium. "The most important time to get a sufficient amount of calcium is while bone growth and consolidation are occurring, a period that continues until approximately age 30 to 35," says Marilyn Stephenson, a registered dietitian with FDA's Center for Food Safety and Applied Nutrition. "The idea is, if you can build a maximum peak of calcium deposits early on, this may delay fractures that occur later in life."

The recommended dietary allowance (RDA) for calcium for woman 19 to 24 is 1,200 milligrams per day. For women 25 and older, the allowance drops to 800 milligrams, but that is still a significant amount, says Stephenson. "The need for good dietary sources of calcium continues throughout life," she says.

How do you get enough calcium without too many calories and fat? After all, the foods that top the calcium charts — milk, cheese, ice cream — aren't calorie and fat lightweights.

"There are lots of lower fat choices," says Stephenson. "There's 1 percent or skim milk instead of whole milk. There's a good variety of lower fat cheeses, yogurts, and frozen yogurts, and there's a whole flock of substitutes for ice cream."

In addition to dairy foods, other good sources of calcium include salmon, tofu (soybean curd), certain vegetables (for example, broccoli), legumes (peas and beans), calcium-enriched grain products, lime-processed tortillas, seeds, and nuts.

Iron

For women, the RDA for iron is 15 milligrams per day, 5 milligrams more than the RDA for men. Women need more of this mineral because they lose an average of 15 to 20 milligrams of iron each month during menstruation. Without enough iron, iron deficiency anemia can develop and cause symptoms that include pallor, fatigue and headaches.

After menopause, body iron stores generally begin to increase. Therefore, iron deficiency in women over 50 may indicate blood loss from another source, and should be checked by a physician.

Animal products — meat, fish and poultry — are good and important sources of iron. In addition, the type of iron, known as heme iron, in these foods is well absorbed in the human intestine.

Dietary iron from plant sources, called non-heme, are found in peas and beans, spinach and other green leafy vegetables, potatoes, and whole-grain and iron-fortified cereal products. Although non-heme iron is not as well absorbed as heme iron, the amount of non-heme iron absorbed from a meal is influenced by other constituents in the diet. The addition of even relatively small amounts of meat or foods containing vitamin C substantially increases the total amount of iron absorbed from the entire meal.

Calories and Weight Control

The Food and Nutrition Board of the National Research Council recommends that the average woman between 23 and 50 eat about 2,200 calories a day to maintain weight.

The best way for a woman to determine whether she's eating the right number of calories is to "keep stepping on the scale," says FDA's Stephenson.

She cautions, however, that cutting back on calories isn't always the answer to losing weight. "You don't really want to cut back any more [calories] if you're down around that [1,500 calories] range," says Stephenson. She explains that the fewer the calories you have to work with, the harder it is to meet all your daily requirements for a healthy diet.

"If you find you are gaining weight, you need to think of not only cutting calories, but also about increasing exercise," she says. "Calories are only half the equation for weight control. Physical activity burns calories, increases the proportion of lean to fat body mass, and raises your metabolism. So, a combination of both calorie control and increased physical activity is important for attaining healthy weight.

"On the other hand, if you've been pigging out — well, you know what you have to do."

Cholesterol

Women tend to have higher levels than men of a desirable type of cholesterol called HDLs (high-density lipoproteins) until menopause, leading some researchers to believe there is a link between HDLs and estrogen levels. But this doesn't let women off the hook — a diet high in saturated fat and cholesterol can still mean trouble.

For both women and men, blood cholesterol levels of below 200 milligrams are desirable. Levels between 200 and 239 milligrams are considered borderline, and anything over 240 milligrams is high. High levels of blood cholesterol increase the risk of coronary heart disease.

To keep levels in the good range, the National Cholesterol Education Program of the National Heart, Lung, and Blood Institute recommends eating no more than 300 milligrams of cholesterol a day. Cholesterol is found only in food from animal sources, such as egg yolks, dairy products, meat, poultry, shellfish, and — in smaller amounts — fish and some processed products containing animal foods.

Even more important than limiting cholesterol to under 300 milligrams is keeping saturated fat to under 10 percent of total calories, says Nancy Ernst, the nutrition coordinator for the National Heart, Lung, and Blood Institute.

"Don't even think about cholesterol in your diet," says Ernst. "Focus on reducing saturated fat."

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.