Low energy, muscle weakness, fatigue and irritability have long been recognized as symptoms of iron deficiency anemia. However, a study published in the “British Medical Journal” suggested that these symptoms may start long before lack of iron leads to anemia. The 2003 study, which has yet to be replicated, found that iron supplements corrected low energy in women with only mild or moderately depleted iron stores.
Iron balance varies from day to day. Some days, you may consume more than you need; other days, you may consume less. If the days when you consume too little outnumber the days when you consume too much, lack of iron becomes cumulative and depletes your body’s stores. At this stage, blood tests will show decreases in serum iron and ferritin, and an increase in total iron binding capacity. As your iron stores are exhausted, red blood cells are affected. At this stage, blood tests will also show a decrease in the size, color and number of red blood cells, a condition known as iron deficiency anemia.
Low energy may be accompanied by other symptoms, such as a blueish cast to the whites of the eyes, pale skin, brittle or spoon-shaped nails, thinning hair, sore tongue, shortness of breath upon minimal exertion, decreased appetite and headaches. Associated symptoms may only become obvious with prolonged or severe lack of iron. Changes often develop slowly, so they may be more obvious to people who see you infrequently, compared to people who see you on a daily basis.
Treatment for low energy from lack of iron begins with replenishing your iron. Your doctor may recommend that you take an oral iron supplement, such as ferrous sulfate or ferrous gluconate, in doses of 325mg one to three times per day. Oral iron supplements can interfere with other medications, so take them exactly as your doctor directs. Your energy levels may begin to improve within a few days of starting treatment. Allow two weeks for full benefits. However, it may take six months or a year of treatment for iron stores to recover completely.
Prevent low energy from lack of iron by consuming an iron-rich diet or taking a daily multivitamin with minerals. Excellent food sources of iron include lean meats, poultry, fish, oysters and clams. The iron in plant foods such as legumes and enriched grains is more difficult for your body to absorb. Consuming foods rich in vitamin C, such as citrus fruits, tomatoes, peppers, broccoli and potatoes, improves the absorption of iron from both plant and animal foods. If you became iron deficient on an iron-rich diet or if you cannot change your diet, ask your doctor if a multivitamin with minerals might help.
Low energy may be caused by factors other than lack of iron. Your doctor may need to rule out other conditions, such as depression, infections, cancer or autoimmune disease. In some cases, low energy is caused by more than one factor. Oral iron supplements do not work for all people. You may need follow-up medical appointments or repeat blood tests to confirm that iron supplements are working for you.
- “British Medical Journal”; Iron Supplementation for Unexplained Fatigue in Non-Anaemic Women; Bernard Favrat, M.D. et al.; May 24, 2003
- Harvard Medical School: Brigham and Women's Hospital: Iron Deficiency
- MedlinePlus Supplements: Iron
- "Harrison's Principles of Internal Medicine, 23rd Edition”; Anthony S. Fauci, M.D. et al.; 2008