Anemia: How Food and Vitamins Can Help
If you're feeling exhausted (despite lots of sleep), have decreased energy, and seem to be unusually pale, the culprit could be some form of anemia.
Although iron-deficiency anemia is by far the most common form of anemia, there are other types. Here, we'll discuss three forms of anemia that are related to nutrition.
More Than Just a Lack of Iron
Anemia is any blood disorder in which the number and/or size of the red blood cells are changed. Red blood cells—with the help of iron-containing hemoglobin—move oxygen from your lungs to bodily tissues. Any change in the size or amount of these cells affects how oxygen is transported within your body. This in turn can affect your energy level greatly.
What Are the Symptoms of Anemia?
"The symptoms of anemia are numerous and affect many organ systems in the body," says Susan M. Lark, MD, of Stanford University, a physician specializing in women's health. "Often the symptoms seem vague and misleading to women and their physicians."
Symptoms of anemia include:
- Fatigue and dizziness
- General weakness
- Shortness of breath
- Loss of appetite
- Brittle and ridged nails
The "Nutritional" Anemias
In the United States, 20% of women of childbearing age suffer from iron-deficiency anemia, compared with only 2% of men. It can be caused by the following:
- Deficiency of iron in the diet
- An accident or trauma that causes acute blood loss
- Gradual blood loss (bleeding from the intestines or menstruation)
Other than women of childbearing age, children and teens are the next most likely to suffer from iron-deficiency anemia. And infants whose mothers experienced anemia during pregnancy are more susceptible to developing anemia.
"During an average menstrual period, it is estimated that a woman loses approximately 18 milligrams of iron through the loss of red blood cells," says Dr. Lark. Since iron is responsible for the production of hemoglobin, which carries oxygen, anemia may result if iron is not replenished.
This type of anemia is primarily associated with inadequate intake or utilization of vitamin B-12 and folic acid—two vitamins necessary for cell division. Thus cells that need rapid replenishment, such as blood cells, are most often affected by a deficiency of these vitamins. The result is that fewer red blood cells are produced and available to carry oxygen to the body's cells, resulting in anemia.
A decreased intake of folic acid from food results in megaloblastic anemia. Pregnancy, breast-feeding, and periods of rapid growth, which increase the body's need for folic acid, can also contribute to anemia. Deficiencies of iron, zinc, or vitamin C will make folic acid less available to the body, and heavy alcohol consumption will increase folic acid requirements.
Vitamin B-12 is found in animal products. Thus vegetarians who consume dairy and egg products are not at increased risk for B-12 deficiency, while individuals who are strict vegans (and their breast fed infants) are most at risk for B-12 deficiency.
Aging also affects B-12 status because less acid is produced in the stomach as we age. Acid helps to release the active form of vitamin B-12 in the stomach. From the stomach B-12 travels down the intestines where it is absorbed into the body in the small intestines. Therefore people who have malabsorption are also at risk for B-12 deficiency.
Causes of the megaloblastic anemias include:
- Inadequate intake or absorption of foods with a high B-12 content, such as meat, poultry, fish, cheese, milk, and eggs
- Inadequate intake or absorption of foods rich in folic acid, such as green vegetables, whole grains, legumes, leafy greens, broccoli, brussel sprouts, asparagus, citrus fruits, strawberries, wheat germ, and brewer's yeast
- Overcooking foods, which destroys folic acid
- Deficiencies of vitamin C, iron, and zinc
- Low levels of acid in the stomach
- Removal of parts of the stomach or small intestine
- Gluten sensitivity
- Pernicious anemia (see below)
This is a form of megaloblastic anemia caused by the absence of intrinsic factor—a chemical substance secreted by cells in the stomach that makes absorption of vitamin B-12 possible. Lack of intrinsic factor is thought to be caused by a genetic deficiency or an autoimmune disorder. A decrease in intrinsic factor is also seen in individuals with gluten (wheat, oats, rye) sensitivity or in people who have had surgery affecting parts of the small intestine. Vitamin B-12 injections are the traditional treatment for pernicious anemia, but many doctors are now reporting success with oral B-12 replacement.
Pernicious anemia usually affects adults. The symptoms of this disorder come on gradually and may not be immediately recognized. Megaloblastic anemia of any sort must be properly diagnosed and treated because serious problems with muscles and balance may occur if anemia due to vitamin B-12 deficiency is treated with folic acid alone.
Making the Diagnosis
Your doctor will conduct a full medical examination to diagnose anemia and rule out another significant illnesses. It is important to tell the doctor if you have a family history of anemia, gall bladder disease, jaundice, or an enlarged spleen. Your dietary habits are also extremely important for making the diagnosis of the nutritional anemias. If you are a female, you must tell your doctor about unusually heavy menstrual periods.
You should also report whether you've noticed the presence of blood in your stools (bowel movements). Physicians often perform a rectal exam test for the presence of less obvious blood in your stool—often the cause of iron-deficiency anemia.
Blood Tests and Blood Smears
The basic laboratory tests for diagnosing anemia are a complete blood count (CBC) and blood smears.
A complete blood count is performed to assess the red blood cells. It yields two important numbers:
- Hemoglobin—the amount of iron in the red blood cells
- Hematocrit—the percentage of red blood cells in the blood
Blood smears involve pricking your finger and smearing a drop or two of blood onto a slide for microscopic examination. A technician will then classify your blood by color, size, and shape. A blood test can also measure the amount of ferritin, an important iron-storage protein. Low ferritin levels indicate chronic iron deficiency.
Treating the Nutritional Anemias
Physicians recommend a diet rich in iron for people who have iron-deficiency anemia.
Iron-rich foods include:
- Beef liver
- Wheat germ
- Dried fruit
- Iron-fortified cereals
- Chicken giblets
- Egg yolks
- Enriched grain products (including certain breakfast cereals)
- Beans and other legumes
- Leafy green vegetables
- Milk and other dairy products
Felicia Busch, registered dietitian and author of The New Nutrition, recommends the following dietary recommendations for the "nutritional" anemias:
- Variety: Choose a healthful variety of foods, especially those rich in iron and folic acid, such as lean red meat, foods fortified with iron and folic acid, and leafy green vegetables.
- Vitamin C: Include plenty of foods rich in vitamin C when you eat foods that contain iron. The vitamin C will help absorb more of the available iron.
- Cast-iron Cooking: Use cast-iron cookware. Tiny iron particles from the cookware are transferred to food and can provide a significant source of dietary iron.
- Don't Smoke: Smoking increases vitamin requirements and has a negative effect on your health in general.
- Supplements: In addition to dietary changes, taking iron supplements may be necessary in some cases. First, talk to your doctor to find out if a supplement is advisable for you. Since iron supplements often cause constipation, upset your stomach, and cause nausea, be sure to eat extra fiber and take iron with a full meal. Be sure that any megaloblastic anemia is properly diagnosed before treatment with folic acid is begun. As noted above, serious consequences can occur if anemia due to vitamin B-12 is incorrectly diagnosed and treated.
American Dietetic Association
American Society of Hematology
Cooley's Anemia Foundation, Inc.
Dietitians of Canada
American Dietetic Association. Available at: http://www.eatright.org/cps/rde/xchg/ada/hs.xsl/index.html.
American Society of Hematology
F. Busch. The New Nutrition: From Antioxidants to Zucchini. John Wiley & Sons, 2000.
E. Uthman. Understanding Anemia. University Press of Mississippi, 1998.
Last reviewed May 2008 by Dianne Scheinberg MS, RD, LDN
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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