What Nutrient is Lacking if I Have Anemia?

October 31, 2025 •

3 min read

The World Health Organization reports that anemia affects over 30% of the global population, with the most common cause being a nutritional deficiency. If you have anemia, determining what nutrient is lacking is the first crucial step toward effective treatment and symptom management.

Quick Summary

Anemia is often caused by a deficiency in key nutrients like iron, vitamin B12, or folate, which are all vital for healthy red blood cell production. Identifying the specific nutrient lacking is essential for appropriate dietary adjustments and medical treatment.

Key Points

Iron is Key for Hemoglobin: The most common nutrient deficiency causing anemia is iron, which is necessary for producing hemoglobin to carry oxygen.
Vitamin B12 and Folate are Vital: Deficiencies in Vitamin B12 and Folate (B9) lead to a type of anemia called megaloblastic anemia, where red blood cells are abnormally large.
Diet and Absorption are Factors: Anemia can result from not consuming enough iron, B12, or folate, or from underlying conditions that prevent the body from properly absorbing them.
Symptoms Require Medical Attention: Persistent fatigue, weakness, and paleness are key symptoms that warrant a visit to a doctor for a blood test.
Diagnosis is Necessary: A blood test is essential to determine the specific type of deficiency, as treatment strategies for iron, B12, and folate deficiencies differ significantly.
Vitamin C Boosts Iron Absorption: Consuming foods rich in vitamin C, like citrus fruits, can enhance the body's absorption of iron from plant-based sources.

Common Nutritional Deficiencies that Cause Anemia

While multiple factors can cause anemia, nutritional deficiencies are among the most frequent, impacting the body's ability to produce or use red blood cells effectively. The most common deficiencies are iron, vitamin B12, and folate.

Iron-Deficiency Anemia

Iron is an essential mineral needed to produce hemoglobin, the protein in red blood cells that carries oxygen. Low iron intake or poor absorption leads to iron-deficiency anemia, the most prevalent form. Causes include insufficient diet, blood loss, increased needs during pregnancy, or malabsorption issues.

Vitamin B12-Deficiency Anemia

This type, also called megaloblastic or pernicious anemia, occurs when there isn't enough vitamin B12 for healthy red blood cell creation. It can be due to low dietary intake (mainly found in animal products) or, more commonly, malabsorption. Pernicious anemia is an autoimmune condition where the body attacks the intrinsic factor needed for B12 absorption.

Folate-Deficiency Anemia

Folate (vitamin B9) is also vital for red blood cell formation. Deficiency, from low intake or poor absorption, results in large, underdeveloped red blood cells, another form of megaloblastic anemia. Folate is especially important during pregnancy.

Less Common Nutritional Deficiencies

Besides iron, B12, and folate, other nutrient deficiencies can contribute to anemia:

Vitamin A: Impacts iron metabolism.
Vitamin C: Helps absorb non-heme iron.
Copper: Aids iron absorption and utilization.

Symptoms and Diagnosis

Anemia symptoms vary and often worsen over time. Common signs include fatigue, weakness, pale skin, shortness of breath, dizziness, and an irregular heartbeat. A Complete Blood Count (CBC) and tests for iron, ferritin, B12, or folate levels are used for diagnosis.

Comparison of Major Nutritional Anemias


Feature	Iron-Deficiency Anemia	Vitamin B12-Deficiency Anemia	Folate-Deficiency Anemia
Cause	Low dietary intake, chronic blood loss, poor absorption	Inadequate intake (especially vegan diet), poor absorption (e.g., pernicious anemia)	Low dietary intake, poor absorption (e.g., intestinal diseases)
Red Blood Cells	Small (microcytic) and pale (hypochromic)	Abnormally large (megaloblastic or macrocytic)	Abnormally large (megaloblastic or macrocytic)
Common Symptoms	Fatigue, weakness, pale skin, brittle nails	Fatigue, weakness, pale skin, neurological symptoms (numbness, tingling)	Fatigue, weakness, pale skin, smooth tongue, diarrhea
Dietary Sources	Red meat, liver, seafood, spinach, lentils, fortified cereals	Meat, fish, eggs, dairy, fortified foods	Dark green leafy vegetables, legumes, asparagus, fortified grains
Absorption Helper	Vitamin C	Intrinsic factor (produced in the stomach)	(N/A)

Treatment and Dietary Management

Supplementation

Treatment for nutritional anemia usually involves supplements. Iron supplements are common for iron deficiency, while B12 and folate deficiencies are treated with injections or tablets. It's vital to follow medical advice on dosage, as excessive intake can be harmful.

Dietary Adjustments

Adjusting your diet is crucial for prevention and management. Increase iron-rich foods, pairing plant-based sources with vitamin C. For B12, consume animal products or fortified foods/supplements for vegans. For folate, eat leafy greens, legumes, and fortified grains.

Considerations for Different Anemia Types

Not all anemia is nutritional. Conditions like anemia of chronic disease or sickle cell anemia require different medical approaches. Always consult a healthcare provider for diagnosis before treatment. More information on blood disorders is available from the American Society of Hematology.

Conclusion

Anemia can stem from various causes, but deficiencies in iron, vitamin B12, and folate are the most frequent. Addressing these through diet and supplements, under medical guidance, effectively treats the condition and symptoms. Accurate diagnosis is key, as self-treatment can mask underlying issues.

Next Steps for Action

If you suspect anemia, see a doctor for a blood test to identify the specific deficiency. They will recommend a personalized plan, which may include diet changes, supplements, or further investigation for causes like malabsorption or blood loss. Do not self-medicate without a diagnosis.

Sources

Anaemia - World Health Organization (WHO), URL: https://www.who.int/health-topics/anaemia Iron deficiency anemia - Symptoms & causes - Mayo Clinic, URL: https://www.mayoclinic.org/diseases-conditions/iron-deficiency-anemia/symptoms-causes/syc-20355034 Nutritional-deficiency anemia: Causes, symptoms, and treatment - Medical News Today, URL: https://www.medicalnewstoday.com/articles/188770 Vitamin B12 or folate deficiency anaemia - NHS inform, URL: https://www.nhsinform.scot/illnesses-and-conditions/nutritional/vitamin-b12-or-folate-deficiency-anaemia/

Frequently Asked Questions

The most common nutrient deficiency causing anemia is iron deficiency. Iron is essential for the production of hemoglobin, the protein in red blood cells that carries oxygen. When iron levels are low, the body cannot produce enough healthy red blood cells, leading to iron-deficiency anemia.

In addition to iron, deficiencies in vitamin B12 and folate (vitamin B9) can also cause anemia. These nutrients are critical for producing healthy red blood cells, and a lack of either can lead to megaloblastic anemia, characterized by abnormally large red blood cells.

Symptoms of nutritional anemia often include extreme fatigue, weakness, pale skin, shortness of breath, dizziness, and headaches. Specific deficiencies can also cause unique symptoms, such as neurological problems (B12 deficiency) or a sore tongue (folate deficiency).

Vegan and vegetarian diets can increase the risk of iron and vitamin B12 deficiency because these nutrients are less bioavailable or absent in plant-based foods. Those following these diets should focus on consuming iron-rich plant foods (like lentils and spinach) with vitamin C and eating fortified cereals or taking supplements.

Pernicious anemia is an autoimmune condition and a type of B12-deficiency anemia. The body attacks the intrinsic factor, a protein necessary for absorbing vitamin B12 from food. Because it's a malabsorption issue, pernicious anemia is not typically caused by a poor diet alone.

Vitamin C plays a crucial role by enhancing the absorption of non-heme iron, the type of iron found in plant-based foods. Pairing iron-rich plant foods with sources of vitamin C, such as citrus fruits or bell peppers, can significantly improve iron uptake.

Yes, anemia can also be caused by chronic diseases (like kidney disease), infections, blood loss, heavy menstrual cycles, inherited disorders (like sickle cell anemia), and other medical conditions. Nutritional deficiencies are just one of many potential causes, highlighting the importance of a proper medical diagnosis.