Iron is present in a variety of animal and plant foods, including organ meats, fish, legumes, whole grains and green, leafy vegetables. Unlike many other vitamins and minerals, your body cannot excrete excess iron. As such, obtaining all of your daily intake from dietary sources is the best way to avoid suffering the ill health effects of iron overconsumption. If your doctor recommends that you take iron supplements, however, you can protect yourself from these issues by taking only the recommended daily dose.
Dietary Reference Intakes
Three factors affect the amount of iron that you should take in a day: age, gender and reproductive status. The dietary reference intake for adult men of all ages is 8 milligrams per day. Reproductive-age women should take 18 milligrams per day and only 8 milligrams after menopause. These recommendations change for pregnant and nursing women, who should respectively consume 27 and 9 milligrams per day. Safe amounts of iron for children also vary, with recommendations ranging from 7 to 15 milligrams per day depending on your child's age and gender.
Different iron supplements contain varying amounts of iron. For example, ferrous fumarate supplements contain approximately 108 milligrams per tablet, ferrous sulfate contains 65 milligrams and ferrous gluconate contains 35 milligrams per tablet. As such, one tablet of any of these supplements meets your daily iron needs regardless of your age, gender and reproductive status. To ensure that your body is absorbing these sources of iron, you should pair your iron supplements with citrus fruits. Their high vitamin C and citric acid contents help to boost your body's ability to absorb iron and reduce the impact of compounds that inhibit iron absorption, such as the tannins in black tea.
The University of Maryland Medical Center states that you can regularly eat up to 45 milligrams of iron per day without any ill health effects. Although larger amounts than this may be safe for most people, regularly taking as little as one iron supplement per day can lead to a condition called iron overload disorder. Extremely high amounts of iron can cause much more severe and immediate effects. Taking 50 to 100 times your recommended daily amount can lead to iron overdose and severe iron toxicity. For example, an adult woman of reproductive age can overdose on approximately 14 ferrous sulfate tablets, which is the most common form of iron supplement.
Symptoms and Considerations
Iron overload disorder has a variety of symptoms, with common examples including liver damage, skin discoloration and diabetes. Severe iron toxicity has more immediate effects, because extremely high amounts of iron destroy cells in your gastrointestinal tract. These include vomiting and bloody diarrhea, with untreated iron overdoses potentially resulting in death. As iron overdose is the most common form of accidental poisoning among children, you should always store iron supplements away from the reach of children in child-proof containers. In addition, you should only take iron supplements on the advice of your family doctor or nutritionist.
- University of Maryland Medical Center: Iron
- The Dietitian's Guide to Vegetarian Diets: Issues and Applications, Third Edition; Reed Mangels et al.
Matthew Lee has been writing professionally since 2007. Past and current research projects have explored the effect of a diagnosis of breast cancer on lifestyle and mental health and adherence to lifestyle-based (i.e. nutrition and exercise) and drug therapy treatment programs. He holds a Master of Arts in psychology from Carleton University and is working toward his doctorate in health psychology.