Anemia is a general term for a category of blood conditions that affect the red blood cells or the oxygen-carrying hemoglobin they contain.
In anemia, there is either a reduction in the number of red blood cells in circulation or a decrease in the amount or quality of hemoglobin. There are many causes of anemia, including severe blood loss, genetic disorders, and serious diseases. (See iron deficiency anemia, pernicious anemia [vitamin B12-related], and sickle cell anemia.) Anyone with unexplained anemia should have the cause determined by a qualified doctor.
Some athletes appear to have anemia when their blood is tested, but this may be a normal adaptation to the stress of exercise,1 which does not need treatment. Further evaluation by a qualified doctor is necessary.
What are the symptoms of anemia?
Some common symptoms of anemia include fatigue, lethargy, weakness, poor concentration, and frequent colds. A peculiar symptom of iron-deficiency anemia, called pica, is the desire to eat unusual things, such as ice, clay, cardboard, paint, or starch. Advanced anemia may also result in lightheadedness, headaches, ringing in the ears (tinnitus), irritability, pale skin, unpleasant sensations in the legs with an uncontrollable urge to move them, and getting out of breath easily.
Dietary changes that may be helpful for anemia
Severe protein deficiency can cause anemia because protein is required for normal production of hemoglobin and red blood cells.2 However, this deficiency is uncommon in healthy people living in developed countries.
Thalassemia is an inherited type of anemia that is most common in people of Mediterranean descent. Children with severe thalassemia often have reduced growth rates that may be partially due to inadequate diets. This problem is primarily found in developing countries.3
Nutritional supplements that may be helpful for anemia
Deficiencies of iron, vitamin B12, and folic acid are the most common nutritional causes of anemia.4 Although rare, severe deficiencies of several other vitamins and minerals, including vitamin A,5 6 vitamin B2,7 vitamin B6,8 9 vitamin C,10 and copper,11 12 can also cause anemia by various mechanisms. Rare genetic disorders can cause anemias that may improve with large amounts of supplements such as vitamin B1.13 14
Taurine has been shown, in a double-blind study, to improve the response to iron therapy in young women with iron-deficiency anemia.15 The amount of taurine used was 1,000 mg per day for 20 weeks, given in addition to iron therapy, but at a different time of the day. The mechanism by which taurine improves iron utilization is not known.
Hemolytic anemia refers to a category of anemia in which red blood cells become fragile and undergo premature death. Vitamin E deficiency, though quite rare, can cause hemolytic anemia because vitamin E protects the red blood cell membrane from oxidative damage. Vitamin E deficiency anemia usually affects only premature infants and children with cystic fibrosis.16 17 Preliminary studies have reported that large amounts (typically 800 IU per day) of vitamin E improve hemolytic anemia caused by a genetic deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD)18 19 20 and anemia caused by kidney dialysis.21 22
People with severe thalassemia who receive regular blood transfusions become overloaded with iron, which increases damaging free radical activity and lowers antioxidant levels in their bodies.23 24 25 26 Some people with milder forms of thalassemia may also have iron overload.27 Iron supplements should be avoided by people with thalassemia unless iron deficiency is diagnosed. Preliminary studies have found that oral supplements of 200 to 600 IU per day of vitamin E reduce free radical damage to red blood cells in thalassemia patients.28 29 30 However, only injections of vitamin E have reduced the need for blood transfusions caused by thalassemia.31 32
Test tube studies have shown that propionyl-L-carnitine (a form of L-carnitine) protects red blood cells of people with thalassemia against free radical damage.33 In a preliminary study, children with beta thalassemia major who took 100 mg of L-carnitine per 2.2 pounds of body weight per day for three months had a significantly decreased need for blood transfusions.34 Some studies have found people with thalassemia to be frequently deficient in folic acid, vitamin B12,35 and zinc.36 37 Researchers have reported improved growth rates in zinc-deficient thalassemic children who were given zinc supplements of 22.5 to 90 mg per day, depending on age.38 39 Magnesium has been reported to be low in thalassemia patients in some,40 41 but not all,42 studies. A small, preliminary study reported that oral supplements of magnesium, 7.2 mg per 2.2 pounds of body weight per day, improved some red blood cell abnormalities in thalassemia patients.43
Sideroblastic anemia refers to a category of anemia featuring a buildup of iron-containing immature red blood cells (sideroblasts). One type of sideroblastic anemia is due to a genetic defect in an enzyme that uses vitamin B6 as a cofactor.44 45 Vitamin B6 supplements of 50 to 200 mg per day partially correct the anemia, but must be taken for life.46
Are there any side effects or interactions with anemia?
Refer to the individual supplement for information about any side effects or interactions.