Could a vitamin or mineral deficiency be behind your fatigue?

The world moves at a hectic pace these days. If you feel like you're constantly running on empty, you're not alone. Many people say that they just don't have the energy they need to accomplish all they need to. Sometimes the cause of fatigue is obvious — for example, getting over the flu or falling short on sleep. Sometimes a vitamin deficiency is part of the problem. It might be worth asking your doctor to check a few vitamin levels, such as the three we've listed below.

• Iron. Anemia occurs when there aren't enough red blood cells to meet the body's need for oxygen, or when these cells don't carry enough of an important protein called hemoglobin. Fatigue is usually the first sign of anemia. A blood test to measure the number of red blood cells and amount of hemoglobin can tell if you have anemia. The first step in shoring up your body's iron supply is with iron-rich foods (such as red meat, eggs, rice, and beans) or, with your doctor's okay, over-the-counter supplements.
   
• Vitamin B₁₂. Your body needs sufficient vitamin B₁₂ in order to produce healthy red blood cells.  So a deficiency in this vitamin can also cause anemia. The main sources of B₁₂ are meat and dairy products, so many people get enough through diet alone. However, it becomes harder for the body to absorb B₁₂ as you get older, and some illnesses (for example, inflammatory bowel disease) can also impair absorption. Many vegetarians and vegans become deficient in B₁₂ because they don't eat meat or dairy. When B₁₂ deficiency is diet-related, oral supplements and dietary changes to increase B₁₂ intake usually do the trick. Other causes of B₁₂ deficiency are usually treated with regular injections of vitamin B₁₂.
   
• Vitamin D. A deficit of this vitamin can sap bone and muscle strength. This vitamin is unique in that your body can produce it when your skin is exposed to sunlight, but there also aren't many natural food sources of it. You can find it in some types of fish (such as tuna and salmon) and in fortified products such as milk, orange juice, and breakfast cereals. Supplements are another way to ensure you're getting enough vitamin D (note that the D₃ form is easier to absorb than other forms of vitamin D).

For more ways to combat fatigue, buy Boosting Your Energy, a Special Health Report from Harvard Medical School.