|DOES IT WORK?||For people with iron deficiency anemia, taking an iron supplement will probably improve performance in both strength and endurance activities. But if you get enough iron from your diet, taking extra iron won’t help. It’s not clear whether milder iron deficiency without anemia reduces exercise and athletic performance.|
|IS IT SAFE?||Taking less than 45 milligrams of iron in a supplement is safe for teenagers and adults. Higher doses can cause upset stomach, constipation, nausea, abdominal pain, vomiting, and fainting. However, doctors sometimes prescribe large amounts of iron for a short time to treat iron-deficiency anemia.|
|BOTTOM LINE||Taking enough iron in supplements to treat iron-deficiency anemia improves exercise capacity. But a healthcare provider should diagnose this condition before you start taking iron supplements. If you want to improve your athletic performance, you should eat a healthy diet containing foods rich in iron, such as lean meats, seafood, poultry, beans, nuts, and raisins. If needed, an iron-containing dietary supplement can help you get the recommended amount of iron.|
|REMARK||Many performance supplements in the marketplace contain more than one ingredient, and ingredients can work differently when they’re combined. Because most ingredient combinations have not been studied, it is not known how effective or safe they are in improving performance.|
Source: U.S. Department of Health & Human Services, National Institutes of Health, Office of Dietary Supplements (2017).