If you are 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 will 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 decreased. 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 doctor specializing in women's health. "Often the symptoms seem vague and misleading to women and their doctors."

Symptoms of anemia include:

  • Fatigue and dizziness
  • General weakness
  • Shortness of breath
  • Paleness
  • Loss of appetite
  • Brittle and ridged nails

The "Nutritional" Anemias

Iron-Deficiency Anemia

In the US, women of childbearing age are more likely to suffer from iron-deficiency anemia than 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.

"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.

Megaloblastic Anemia

This type of anemia is primarily associated with inadequate intake or utilization of vitamin B12 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 can result in anemia. Pregnancy, breastfeeding, and periods of rapid growth, which increase the body's need for folic acid, can also contribute to anemia. Heavy alcohol consumption will increase folic acid requirements.

Vitamin B12 is found in animal products. Thus, vegetarians who consume dairy and egg products are not at increased risk for B12 deficiency, while individuals who are strict vegans (and their breastfed infants) are most at risk for B12 deficiency.

Aging also affects B12 status because less acid is produced in the stomach as we age. Acid helps to release the active form of vitamin B12 in the stomach. From the stomach, B12 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 B12 deficiency.

Causes of the megaloblastic anemias include:

  • Inadequate intake or absorption of foods with a high B12 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
  • Alcoholism
  • Overcooking foods, which destroys folic acid
  • Low levels of acid in the stomach
  • Removal of parts of the stomach or small intestine
  • Gluten sensitivity
  • Pernicious anemia (see below)

Pernicious Anemia

Pernicious anemia 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 B12 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 B12 injections are the traditional treatment for pernicious anemia, but the supplement can also be taken orally in large doses.

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 B12 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, gallbladder 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 have noticed the presence of blood in your stools. Doctors often will check the stool for presence of less obvious blood—often the cause of iron-deficiency anemia.

Blood Tests and Blood Smears

The basic lab 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—a protein found in red blood cells
  • Hematocrit—the percentage blood made up by red blood cells

A technician will 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

Doctors recommend a diet rich in iron for people who have iron-deficiency anemia. Iron-rich foods include:

  • Beef liver
  • Poultry
  • Fish
  • Wheat germ
  • Oysters
  • Dried fruit
  • Iron-fortified cereals
  • Eggs

Foods high in Vitamin B12 include:

  • Liver
  • Meat
  • Fish
  • Eggs
  • Milk and other dairy products

Foods high in folic acid include:

  • Liver
  • Chicken giblets
  • Egg yolks
  • Enriched grain products (including certain breakfast cereals)
  • Beans and other legumes
  • Leafy green vegetables
  • Bananas
  • Oranges
  • Peaches

Felicia Busch, registered dietitian and author of The New Nutrition, recommends the following dietary recommendations for the "nutritional" anemias:

  • Variety: Choose a healthy 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.
  • Do not 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 B12 is incorrectly diagnosed and treated.