Raising your red blood cell (RBC) count comes down to giving your body the raw materials it needs to produce healthy red blood cells and removing anything that gets in the way. Normal ranges fall between 4.7 and 6.1 million cells per microliter for men and 4.2 to 5.4 million cells per microliter for women. If your count is low, the cause is almost always a nutrient deficiency, a chronic condition, or blood loss. The strategies below focus on what you can control through diet, supplementation, and lifestyle.
The Three Nutrients That Matter Most
Red blood cells are built in your bone marrow, and the process depends heavily on three nutrients: iron, vitamin B12, and folate. Each plays a distinct role, and being low in any one of them can slow production or cause your body to make cells that are misshapen or too large to function properly.
Iron is the core component of hemoglobin, the protein inside red blood cells that carries oxygen. About 60% of your body’s total iron sits in hemoglobin and muscle tissue. Without enough iron, your marrow still tries to produce red blood cells, but they come out smaller and paler, carrying less oxygen than normal.
Vitamin B12 works as a helper molecule in DNA synthesis. Your bone marrow cells divide rapidly to churn out new red blood cells, and they can’t copy their DNA correctly without B12. The same is true for folate, which B12 helps convert into its active form. When either nutrient is missing, the marrow produces oversized, immature cells that don’t survive long in circulation.
Iron-Rich Foods by Category
Your body absorbs iron from animal sources (called heme iron) more efficiently than iron from plants (non-heme iron). Both count toward your daily intake, but if you rely mostly on plant foods, you’ll need to eat more to compensate. The daily recommendation for iron is 8 mg for adult men and 18 mg for women aged 19 to 50. After menopause, women’s needs drop to 8 mg. During pregnancy, the target jumps to 27 mg. Vegetarians need roughly 1.8 times the standard amount because plant iron is harder to absorb.
Best Animal Sources
- Oysters: 6.9 mg per 3 oysters
- Mussels: 5.7 mg per 3 ounces
- Organ meats: 1.8 to 19 mg per 3 ounces, depending on the type
- Duck breast: 3.8 mg per 3 ounces
- Bison: 2.9 mg per 3 ounces
- Beef: 2.5 mg per 3 ounces
- Sardines: 2.5 mg per 3 ounces
- Crab: 2.5 mg per 3 ounces
Best Plant Sources
- Fortified cereals: 8 to 16 mg per serving, depending on the brand
- Cooked spinach: 6.4 mg per cup
- Soybeans: 4.4 mg per half cup
- Cooked Swiss chard: 4.0 mg per cup
- White beans: 3.3 mg per half cup
- Lentils: 3.3 mg per half cup
- Chickpeas: 2.4 mg per half cup
- Kidney beans: 2.0 mg per half cup
What Blocks Iron Absorption
Eating iron-rich food is only half the equation. Certain compounds in everyday foods and drinks bind to non-heme iron in your gut and prevent it from getting absorbed. Tannins in tea and coffee are a common culprit. Phytates, found in whole grains, seeds, and legumes, are another. Calcium can also compete with iron for absorption. A Harvard review found that these inhibitors reduced non-heme iron absorption by anywhere from 1% to 23%, depending on the amount consumed.
The practical fix is simple: separate your iron-rich meals from your tea, coffee, and calcium supplements by at least an hour or two. Pairing plant-based iron with vitamin C (citrus, bell peppers, tomatoes) does the opposite of these blockers. Vitamin C converts non-heme iron into a form your gut absorbs more readily.
Copper: The Overlooked Mineral
Copper doesn’t get nearly as much attention as iron, but your body can’t use iron properly without it. Copper-dependent enzymes in your body convert iron into the form that can attach to transferrin, the protein that shuttles iron through your bloodstream to your bone marrow. When copper is low, iron gets stuck in storage. You can eat plenty of iron-rich food and still develop anemia if your copper intake is inadequate.
Copper deficiency also appears to shorten the lifespan of red blood cells already in circulation and impair hemoglobin production directly. Good sources include shellfish, nuts, seeds, dark chocolate, and organ meats. Most adults need about 900 micrograms per day, which is easy to reach with a varied diet.
How Your Body Regulates RBC Production
Your kidneys act as the control center. Specialized cells in the kidneys constantly monitor oxygen levels in your blood. When oxygen drops, they ramp up production of a hormone called erythropoietin (EPO), which signals your bone marrow to make more red blood cells. When oxygen levels are adequate, the kidneys dial EPO production back down. This is why kidney disease is one of the most common non-nutritional causes of a low RBC count: damaged kidneys can’t produce enough EPO to keep up.
This same oxygen-sensing system is why altitude affects red blood cell counts. At higher elevations, there’s less oxygen in each breath, so your kidneys respond by increasing EPO output. The body’s initial reaction happens within hours, primarily through a drop in plasma volume that concentrates existing red blood cells. Genuine increases in red blood cell mass take days to weeks of sustained exposure. Athletes sometimes train at altitude specifically to trigger this effect, though the boost is temporary once they return to lower elevations.
Exercise and RBC Count
Regular physical activity, especially aerobic exercise, increases your body’s demand for oxygen. Over time, this sustained demand stimulates your kidneys to produce more EPO and nudges your bone marrow toward higher red blood cell output. You don’t need extreme training for this effect. Consistent moderate exercise like brisk walking, cycling, or swimming creates enough of an oxygen demand to support healthy production. The key is consistency over weeks and months rather than intensity on any single day.
B12 and Folate: Where to Find Them
Vitamin B12 is found almost exclusively in animal products: meat, fish, eggs, and dairy. If you follow a vegan diet, supplementation or B12-fortified foods (like nutritional yeast and fortified plant milks) are essential, not optional. Deficiency can take years to develop because the liver stores several years’ worth, but once stores run out, red blood cell production drops noticeably.
Folate is easier to get from plants. Dark leafy greens, legumes, asparagus, and citrus fruits are all strong sources. Many grain products in the U.S. are also fortified with folic acid, the synthetic form of folate. Adults need 400 micrograms daily, rising to 600 micrograms during pregnancy.
When Diet Alone Isn’t Enough
If a blood test confirms a specific deficiency, targeted supplementation can bring your levels up faster than dietary changes alone. Iron supplements are the most commonly recommended, particularly for women with heavy periods, pregnant women, and people with gastrointestinal conditions that impair absorption. Iron supplements are best absorbed on an empty stomach with vitamin C, though some people need to take them with a small amount of food to avoid nausea.
B12 deficiency sometimes stems not from low intake but from poor absorption. Older adults, people with autoimmune conditions affecting the stomach, and those who’ve had certain gastrointestinal surgeries may not produce enough of the protein needed to absorb B12 from food. In these cases, high-dose oral supplements or injections bypass the absorption problem.
For low RBC counts caused by chronic kidney disease, synthetic EPO given by injection can directly stimulate the bone marrow. This isn’t something you’d pursue on your own, but it’s worth understanding if kidney function is part of your picture.
Other Factors That Lower RBC Count
Heavy alcohol use suppresses bone marrow activity and can lead to both folate deficiency and direct toxicity to developing red blood cells. Reducing alcohol intake is one of the simplest interventions for people whose counts are borderline low.
Chronic inflammation from autoimmune diseases, infections, or certain cancers can also suppress red blood cell production by interfering with iron metabolism and EPO signaling. In these situations, addressing the underlying condition matters more than any dietary adjustment. Hydration plays a subtler role: dehydration concentrates your blood and can make RBC counts appear artificially normal, while overhydration dilutes it. A single blood draw captures a snapshot, so mild fluctuations between tests are common and not always meaningful.