What to Eat If RDW CV Is High: A Comprehensive Dietary Guide

December 27, 2025 •

4 min read

According to Medscape, an elevated Red Cell Distribution Width (RDW) is often an early indicator of nutritional deficiencies, such as iron, folate, or vitamin B12. If your RDW CV is high, modifying your diet to focus on key nutrients is a crucial and proactive step toward improving your red blood cell health.

Quick Summary

An elevated RDW CV reading often points toward nutritional deficiencies affecting red blood cell size variation. Dietary changes can help address these underlying issues by increasing intake of iron, vitamin B12, and folate, which are essential for proper red blood cell production and maturation.

Key Points

RDW Measures Red Blood Cell Variation: A high RDW CV indicates that your red blood cells vary more than normal in size and volume, a condition known as anisocytosis.
High RDW Often Signals Nutrient Deficiencies: The most common causes of a high RDW are deficiencies in iron, vitamin B12, or folate, which are crucial for healthy red blood cell production.
Increase Iron-Rich Foods: Consume sources of both heme iron (meat, poultry) and non-heme iron (spinach, lentils) to address potential iron-deficiency anemia.
Boost Vitamin B12 and Folate Intake: Incorporate foods like beef, dairy, eggs, leafy greens, and legumes into your diet to prevent macrocytic anemia associated with B vitamin deficiencies.
Enhance Nutrient Absorption: Pair non-heme iron sources with vitamin C-rich foods (e.g., citrus fruits, broccoli) to improve absorption. Avoid drinking coffee, tea, or excess alcohol with meals, as they can interfere with iron absorption.
Consult a Healthcare Provider: Always seek professional medical advice for a proper diagnosis before starting any new diet or supplement regimen to address a high RDW.

Understanding a High RDW CV

Red Cell Distribution Width (RDW) is a measurement included in a standard complete blood count (CBC) that indicates the variation in the size and volume of your red blood cells (RBCs). Normally, RBCs are relatively uniform in size. When the RDW is high, it suggests a greater-than-normal variation in cell size, a condition known as anisocytosis. This can be a sign that your body is having trouble producing healthy, uniformly sized red blood cells, often due to a lack of specific nutrients.

Common nutritional deficiencies linked to a high RDW include:

Iron deficiency: A high RDW is a classic sign of early iron-deficiency anemia, as the body begins producing smaller, iron-poor red blood cells alongside the remaining older, normal-sized cells.
Vitamin B12 or folate deficiency: These deficiencies can lead to macrocytic anemia, where the body produces abnormally large red blood cells (macrocytes). The high RDW results from the mix of large and normal-sized cells.
Mixed deficiency: In some cases, a high RDW may indicate a combination of deficiencies, such as low iron and low B12, leading to a mixed population of small and large red blood cells.

While nutritional issues are a primary cause, other conditions like chronic liver disease, kidney disease, and some inherited disorders can also cause an elevated RDW. Therefore, dietary changes should always be pursued under the guidance of a healthcare professional who can correctly diagnose the underlying cause.

Iron-Rich Foods to Add to Your Diet

Iron is a fundamental component of hemoglobin, the protein responsible for carrying oxygen in red blood cells. Correcting an iron deficiency is vital for lowering a high RDW. You can increase your iron intake by consuming the following:

Heme iron sources: This type of iron, found in animal products, is more readily absorbed by the body. Include lean red meat, poultry, and seafood like fish, clams, and oysters.
Non-heme iron sources: This plant-based iron is less easily absorbed but is still an important part of a healthy diet, especially when paired with vitamin C. Good sources include lentils, spinach, kale, fortified cereals, tofu, and legumes.
Enhancing iron absorption: To maximize the intake of non-heme iron, consume it with foods rich in vitamin C, such as citrus fruits, bell peppers, broccoli, and strawberries. You can also cook with cast-iron cookware to increase the iron content of your meals.

Foods High in Vitamin B12 and Folate

These B vitamins are essential for the production and maturation of red blood cells. A deficiency can cause large, immature red blood cells, contributing to a high RDW.

Vitamin B12 Sources

Animal products: Excellent sources include beef, chicken, fish (especially salmon and tuna), dairy products like milk and yogurt, and eggs.
Fortified foods: Vegetarians and vegans can rely on fortified nutritional yeast, breakfast cereals, and plant-based milks to meet their B12 needs.

Folate (Vitamin B9) Sources

Leafy greens: Spinach, kale, romaine lettuce, and other dark leafy greens are packed with folate.
Legumes: Lentils, chickpeas, black beans, and peas are all great sources.
Fruits: Citrus fruits, bananas, and avocados contain good amounts of folate.
Fortified grains: Look for breads, pasta, and cereals that are fortified with folic acid, the synthetic form of folate.

Lifestyle Adjustments for Optimal Blood Health

Beyond specific foods, overall dietary and lifestyle habits play a significant role in managing a high RDW. Remember to discuss these changes with your doctor before implementation.

Limit iron blockers: Tea, coffee, wine, and calcium can interfere with iron absorption. It is recommended to consume these beverages in moderation and at a different time than iron-rich meals.
Stay hydrated: Drinking adequate water is crucial for overall blood volume and health.
Moderate alcohol consumption: Excessive alcohol intake can impair nutrient absorption and red blood cell production.
Regular exercise: Engaging in regular physical activity can stimulate the production of red blood cells, helping your body to naturally regulate its levels.

Comparison of Key Nutrients for High RDW


Nutrient	Primary Function	Food Sources	Absorption Tip	Typical Deficiency Effect
Iron	Hemoglobin production	Red meat, poultry, spinach, lentils	Pair with Vitamin C	Microcytic (small cell) anemia
Vitamin B12	RBC maturation, DNA synthesis	Beef, dairy, eggs, fortified cereals	Primarily from animal sources	Macrocytic (large cell) anemia
Folate (B9)	RBC formation, DNA synthesis	Leafy greens, legumes, citrus fruits	Cook lightly or consume raw	Macrocytic (large cell) anemia

Conclusion

A high RDW CV reading is an important signal from your body that should not be ignored. Often, it points toward a correctable issue involving nutritional deficiencies of iron, vitamin B12, or folate. By proactively adjusting your diet to include a wide variety of foods rich in these essential nutrients, you can support your body's red blood cell production and work towards normalizing your RDW levels. Combining these dietary changes with a healthy lifestyle, such as regular exercise and limiting alcohol, will further optimize your blood health. Remember to always consult with a healthcare provider for an accurate diagnosis and personalized treatment plan before making significant dietary modifications.

Disclaimer: The information provided is for educational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider for any health concerns.

Frequently Asked Questions

RDW CV (Red Cell Distribution Width, Coefficient of Variation) is a lab value measuring the variation in the size of your red blood cells. A high RDW CV means your red blood cells vary significantly in size, which often points toward nutritional deficiencies like low iron, vitamin B12, or folate, affecting red blood cell production.

A high RDW can be linked to several types of anemia. A high RDW with low MCV (mean corpuscular volume) can indicate iron-deficiency anemia. A high RDW with high MCV can indicate folate or vitamin B12 deficiency. A high RDW with a normal MCV can suggest a mixed nutritional deficiency or early stages of an issue.

To increase iron, focus on heme iron from animal sources like red meat, poultry, and fish, which is easily absorbed. Also, include non-heme iron from plant sources like lentils, spinach, and fortified cereals, and pair them with vitamin C-rich foods for better absorption.

Vegans and vegetarians should focus on fortified foods for B12, such as nutritional yeast, plant-based milks, and cereals. For iron, consume plant-based sources like lentils, dark leafy greens, and tofu, pairing them with vitamin C foods like bell peppers or citrus. Folate is found in plenty of plant foods like legumes, leafy greens, and avocados.

Yes, some beverages can affect your body's ability to absorb nutrients essential for red blood cell health. For example, tea, coffee, and alcohol can hinder iron absorption, so it is best to avoid consuming them with iron-rich meals.

The time it takes to see improvement can vary depending on the severity of the deficiency and individual factors. Generally, consistent dietary changes combined with proper supplementation (if recommended by a doctor) can start to show positive changes in subsequent blood tests within a few months.

Besides diet, other lifestyle factors can influence blood health. Regular exercise encourages red blood cell production. Limiting alcohol intake is beneficial, as excessive consumption can interfere with nutrient absorption. Always consult your doctor for a personalized treatment plan.