About 1 in 4 people worldwide struggle with anemia, a condition where your blood doesn’t carry enough oxygen. While most people think anemia is just about iron, doctors now understand it’s much more complicated. This research review shows that anemia can also come from not getting enough vitamin B12, folate, zinc, copper, or vitamin A. The study also reveals that certain foods and ingredients can block your body from absorbing these nutrients, and that infections and inflammation make things worse. Scientists are discovering new ways to prevent and treat anemia, including special diets and new iron supplements, but the best approach depends on where you live and your personal situation.

The Quick Take

  • What they studied: Why so many people around the world have anemia and what causes it beyond just low iron levels
  • Who participated: This was a review of existing research rather than a new study with participants. Scientists looked at hundreds of studies about anemia, infections, diet, and poverty to understand the full picture
  • Key finding: Anemia is caused by many different things working together—not just iron deficiency. Missing vitamins (B12, folate), minerals (zinc, copper, vitamin A), certain foods that block nutrient absorption, infections, and poverty all play important roles
  • What it means for you: If you or someone you know has anemia, doctors need to look at the whole picture, not just iron levels. Treatment might involve different vitamins, changing what you eat, or treating infections. One-size-fits-all solutions don’t work everywhere

The Research Details

This study is a narrative review, which means scientists read and summarized hundreds of research papers about anemia from around the world. They looked at studies about how different nutrients affect anemia, how certain foods block nutrient absorption, how poverty and infections contribute to anemia, and what new treatments are being developed. The researchers organized all this information to show how different factors work together to cause anemia in different populations.

The scientists examined evidence from epidemiological studies (which track health in large groups), clinical trials (where new treatments are tested), and public health programs (that try to prevent disease in communities). By combining all these different types of research, they created a complete picture of why anemia happens and what might help prevent it.

This approach is valuable because it shows how complex anemia really is. Instead of looking at just one cause, the review reveals that anemia usually results from multiple problems happening at the same time in a person’s life.

Understanding all the causes of anemia is important because it helps doctors and public health workers create better solutions. If we only focus on iron, we’ll miss people who need vitamin B12 or folate. This review also shows why the same treatment doesn’t work everywhere—what works in one country might not work in another because of different diets, infections, and living conditions. By understanding the full complexity, we can design smarter, more effective programs to help the most vulnerable people: children, women, and elderly people.

This is a narrative review, which means it summarizes existing research rather than conducting a new experiment. This type of study is good for understanding complex topics and identifying gaps in knowledge, but it relies on the quality of the papers reviewed. The strength of this review comes from examining recent research across many different fields (nutrition, medicine, public health, and economics). However, readers should know that narrative reviews can sometimes reflect the author’s perspective on which studies are most important. The findings are most reliable when they’re supported by multiple independent studies pointing in the same direction.

What the Results Show

The review reveals that anemia affects about 1.92 billion people worldwide—roughly 1 in 4 people. While iron deficiency is the most common cause, many people have anemia from other nutrient deficiencies. Vitamin B12 deficiency is especially common in people who eat plant-based diets or have digestive problems. Folate (a B vitamin) deficiency causes anemia, particularly in pregnant women and people living in poverty. Zinc and copper deficiencies also contribute to anemia, and vitamin A deficiency makes anemia worse.

The research shows that certain foods and ingredients actually prevent your body from absorbing nutrients. Phytates (found in grains and beans), polyphenols (in tea and coffee), and oxalates (in spinach and nuts) can block iron and other mineral absorption. This is especially important for people eating plant-based diets, who may get plenty of these nutrients on paper but can’t actually absorb them.

Infections and chronic inflammation are major contributors to anemia that doctors often overlook. When your body fights an infection or deals with long-term inflammation, it changes how iron is used and absorbed. This is why anemia is so common in developing countries where infections are more prevalent.

The review also highlights that poverty, poor sanitation, and limited access to diverse foods are fundamental causes of anemia. These social factors determine what people can eat and whether they can get medical care.

The review identifies several emerging treatments showing promise. Hepcidin modulation (adjusting a hormone that controls iron) may help treat certain types of anemia. Biofortification—adding nutrients to staple foods like rice and flour—has successfully reduced anemia in some countries. New iron formulations that are easier to absorb and cause fewer side effects are being developed. Plant-based diets can be healthy but require careful planning to ensure adequate B12, iron, and other nutrients. The review notes that successful anemia prevention programs combine multiple approaches: nutrition education, food fortification, treating infections, and improving living conditions.

This review updates and expands on previous understanding of anemia. Earlier research focused mainly on iron deficiency, but this comprehensive review shows that modern anemia is more complex. The findings align with recent research showing that plant-based diets are becoming more common and require special attention to B12 and iron absorption. The review also reflects growing recognition that poverty and infection are root causes of anemia, not just individual dietary choices. This represents a shift from blaming individuals for anemia to understanding the social and environmental factors that cause it.

This is a narrative review, not a new research study, so it summarizes what others have found rather than collecting new data. The conclusions depend on which studies the authors chose to emphasize. Some regions have more research than others, so the review may better reflect anemia in well-studied areas. The review doesn’t provide specific numbers about how common each type of nutrient deficiency is. Finally, while the review identifies promising new treatments, most aren’t yet widely available, so practical options for most people remain limited.

The Bottom Line

If you have anemia, ask your doctor to test for multiple nutrient deficiencies, not just iron (moderate confidence). Eat a variety of foods including meat, fish, eggs, beans, nuts, and leafy greens if possible (high confidence). If you follow a plant-based diet, consider B12 supplements and eat iron-rich foods with vitamin C to improve absorption (high confidence). Treat any infections or chronic health conditions, as these worsen anemia (high confidence). If you live in poverty or have limited food access, ask about food assistance programs and fortified foods in your area (moderate confidence). New treatments like biofortified foods and improved iron supplements may help, but talk to your doctor about what’s available where you live (moderate confidence).

Everyone should care about anemia prevention, but it’s especially important for: pregnant women and women of childbearing age, young children (especially under 5), elderly people, people following plant-based diets, people with digestive disorders, people living in poverty, and people with chronic infections. If you have symptoms like fatigue, shortness of breath, pale skin, or dizziness, see a doctor for testing. People in developed countries with access to diverse foods and healthcare have lower anemia risk but should still be aware of the condition.

If you start treatment for anemia, you might feel more energy within 2-4 weeks, but it takes 2-3 months for blood counts to fully normalize. If you’re making dietary changes, allow 3-6 months to see improvements. Prevention through good nutrition is a long-term commitment—consistent eating habits over months and years prevent anemia from developing. If you’re taking supplements, continue them as long as your doctor recommends, even after you feel better.

Want to Apply This Research?

  • Log daily intake of iron-rich foods (red meat, poultry, fish, beans, fortified cereals), vitamin B12 sources (meat, dairy, eggs, fortified plant milks), and folate sources (leafy greens, legumes, asparagus). Track energy levels and any symptoms like fatigue or shortness of breath on a 1-10 scale. If taking supplements, log doses and timing.
  • Set a daily reminder to eat one iron-rich food with a vitamin C source (like orange juice or tomatoes) to improve absorption. If plant-based, add one B12-fortified food daily or take a supplement. Drink tea and coffee between meals rather than with meals to avoid blocking nutrient absorption. Track weekly whether you’re eating diverse foods across all nutrient groups.
  • Weekly: Review food logs to ensure variety and adequate nutrient sources. Monthly: Check energy levels and symptom tracking to see if diet changes help. Every 3 months: Share logs with your doctor before blood work to discuss whether treatment is working. Long-term: Maintain consistent logging to identify patterns and catch early signs of nutrient deficiency before anemia develops.

This review summarizes scientific research about anemia causes and treatments but is not medical advice. Anemia has many different causes and requires individual diagnosis and treatment. If you experience symptoms like persistent fatigue, shortness of breath, dizziness, or pale skin, consult a healthcare provider for proper testing and diagnosis. Do not start supplements or make major dietary changes without discussing with your doctor, especially if you’re pregnant, nursing, taking medications, or have existing health conditions. The emerging treatments mentioned (hepcidin modulation, novel formulations) may not be available in your area. Treatment recommendations should be personalized based on your specific type of anemia, overall health, and local resources.