Iron Deficiency Anemia: Common Causes and Risk Factors Across Age Groups

Iron deficiency anemia is one of the most prevalent forms of anemia worldwide, occurring when the body lacks sufficient iron to produce adequate hemoglobin—the protein in red blood cells responsible for carrying oxygen. Without enough iron, the body can't generate healthy red blood cells, leading to fatigue, weakness, and a range of other symptoms. While iron deficiency can affect anyone, the underlying causes often vary significantly depending on age, lifestyle, and physiological factors.

Why Infants Are at Risk

Babies are typically born with a store of iron that lasts about six months. After this period, their rapid growth increases their need for iron, but standard infant diets—especially those based primarily on breast milk or formula—may not provide enough of this essential mineral. Breast milk, while highly nutritious, contains only small amounts of iron. As a result, pediatricians strongly recommend introducing iron-rich complementary foods around six months of age.

Foods such as pureed meats, iron-fortified cereals, and egg yolks are excellent sources of dietary iron for infants. Delaying the introduction of these foods can increase the risk of developing iron deficiency anemia during critical developmental stages. Parents should work closely with healthcare providers to ensure proper nutritional planning during infancy to support healthy blood production and cognitive development.

Common Causes in Adults

In adults, iron deficiency anemia often stems from chronic blood loss or inadequate dietary intake. However, the specific contributing factors differ between men and women, as well as across age groups.

Heavy Menstrual Bleeding in Women of Reproductive Age

For premenopausal women, excessive menstrual bleeding (menorrhagia) is a leading cause of iron depletion. Conditions such as uterine fibroids, endometriosis, or hormonal imbalances can lead to abnormally heavy periods, resulting in significant monthly blood loss. Over time, this ongoing loss depletes iron stores faster than they can be replenished through diet alone.

Women experiencing prolonged or unusually heavy periods should seek medical evaluation. Diagnostic procedures may include pelvic exams, ultrasounds, or even biopsy to identify structural abnormalities. Treating the root cause—whether through medication, hormone therapy, or surgery—can dramatically improve iron levels and overall quality of life.

Gastrointestinal Blood Loss in Adults and Older Individuals

In adults, particularly middle-aged and older individuals, gastrointestinal (GI) bleeding is a major contributor to iron deficiency. Unlike menstrual blood loss, GI bleeding is often invisible—referred to as occult bleeding—and may go unnoticed for months or even years.

Common gastrointestinal conditions linked to iron loss include:

• Peptic ulcers caused by H. pylori infection or long-term use of NSAIDs (like ibuprofen or aspirin)
• Colon polyps or colorectal cancer
• Inflammatory bowel diseases such as Crohn's disease or ulcerative colitis
• Hiatal hernias or vascular malformations in the intestines

Because symptoms like fatigue or pallor are often mistaken for general aging or stress, it's crucial to conduct targeted screenings. Stool tests for hidden blood (fecal occult blood test), along with blood markers such as ferritin and transferrin saturation, help detect early signs of deficiency. In many cases, doctors recommend endoscopic evaluations—including gastroscopy and colonoscopy—to visually inspect the digestive tract and identify potential sources of bleeding.

Prevention and Early Detection Matter

While iron deficiency anemia is highly treatable, preventing long-term complications requires early diagnosis and intervention. A balanced diet rich in heme iron (from meat, poultry, and fish) and non-heme iron (from beans, lentils, spinach, and fortified grains), combined with vitamin C to enhance absorption, plays a vital role in maintaining healthy iron levels.

At-risk populations—including infants, menstruating women, and older adults—should undergo regular health checkups. Recognizing the subtle signs of iron deficiency—such as brittle nails, restless legs, or difficulty concentrating—can prompt timely testing and treatment. With proper care, most individuals can restore their iron stores and regain energy, focus, and vitality.