RBC - Kresser Institute Membership Site

Marker Name: RBC

REFERENCE RANGES FOR RBC COUNT:

Laboratory reference range: 4.14–5.80 x 106/µL

Functional reference range: 4.40–4.90 x 106/µL

DESCRIPTION:

Red blood cells (RBCs), also known as erythrocytes, deliver oxygen to cells throughout the body. They also absorb and carry carbon dioxide from tissues to the lungs to be expired and can help buffer blood pH. The most numerous cells in the body, RBCs make up about 40 to 45 percent of blood by volume; a healthy person contains about 600 RBCs for every white blood cell.¹

Oxygen in RBCs is carried by hemoglobin, a large protein molecule with four iron atoms at its center to which oxygen is loosely attached. Oxygenated hemoglobin is red, giving blood its characteristic color. When RBCs lose their oxygen, however, the shape of the hemoglobin molecule changes such that, when viewed through the skin, deoxygenated blood traveling through the veins appears blue.²

Red blood cell function is enhanced by its distinct biconcave disc shape, which adds valuable surface area for the exchange of O₂ and CO₂ without adding volume to the cell. Similarly, RBCs are one of the only cells in the body without a nucleus, which allows them to maximize hemoglobin content while further minimizing volume. RBCs are also highly flexible, enabling them to squeeze through even the smallest-diameter capillaries.¹

Red blood cell production, or erythropoiesis, occurs in the bone marrow and is regulated by a complex array of cytokines and hormones. One key hormone is erythropoietin, produced in the kidneys. Erythropoietin cooperates with other growth factors to stimulate development of red blood cells from multipotent progenitors.³ Once mature, the average lifespan of a red blood cell is 120 days. In order to produce red blood cells at an adequate rate, healthy levels of many key nutrients are needed.^4,5

High red blood cell count (erythrocytosis) can be caused by dehydration, states of decreased oxygen availability, myeloproliferative disorders, states of elevated erythropoietin, certain drugs, and other conditions. A full list of conditions and drugs that can cause high red blood cell count is provided below.^6-13

Low red blood cell count (often defined as anemia) can be caused by normal pregnancy, certain nutrient imbalances, chronic inflammation, bone marrow disorders, certain anemias, endocrine disorders, chronic kidney disease, certain inherited disorders, and specific drugs. A full list of conditions and drugs that can cause low red blood cell count is below.^14-16

To determine the etiology of abnormal RBC level, related markers should be considered, including hemoglobin, serum iron, ferritin, TIBC, UIBC, iron saturation, and other markers in the complete blood count (CBC).

PATHOLOGICAL/CONVENTIONAL RANGE INDICATIONS:

High in:⁶

Dehydration⁸
Smoking
Chronic carbon monoxide poisoning
High-altitude living
Congenital heart disease
Myeloproliferative disorders
- Polycythemia vera
- Essential thrombocytosis
- Primary idiopathic myelofibrosis (myelosclerosis)
- Chronic myelogenous leukemia
Erythropoietin-producing neoplasms (e.g., renal cell carcinoma, hepatocellular carcinoma, haemangioblastoma, etc.)⁷
Certain genetic conditions causing:
- Altered oxygen sensing
- Abnormal hemoglobin oxygen release
Post renal transplant⁹
Autologous blood transfusions
States of hypoxemia¹⁰
- Sleep apnea¹²
- Massive obesity
- Pulmonary fibrosis
- Emphysema
- Hypoventilation
  - Muscle-wasting diseases (e.g., myasthenia gravis)
  - Neurodegenerative diseases
  - Congenital central hypoventilation syndrome
- Right-to-left cardiac shunts
- Ventilation perfusion abnormality
Drugs
- Androgens or anabolic steroids¹¹
- Morphine
- Diuretics¹³

Low in:^14,16

Normal pregnancy
Nutrient imbalances^4,5
- Folate deficiency
- Iron deficiency
- Copper deficiency
- Vitamin B2 deficiency
- Vitamin B3 deficiency
- Vitamin B6 deficiency
- Vitamin B12 deficiency
- Vitamin E deficiency
- Lead poisoning
Chronic inflammation (e.g., chronic infection, malignancy, rheumatologic disorders, inflammatory bowel disease, chronic immune activation, and other inflammatory disorders)
Certain bone marrow disorders (e.g., preleukemia, myeloid leukemia, aplastic anemia, erythroleukemia)
Sideroblastic anemia¹⁵
Alpha and beta thalassemia
Hemolytic anemia (e.g., autoimmune hemolytic anemia, sickle cell anemia, malaria, etc.)¹⁵
Myelophthistic anemia
Endocrine disorders
- Hypothyroidism
- Adrenal corticosteroid deficiency
- Gonadal deficiency
Chronic renal disease
Congenital disorders of DNA synthesis
Drugs
- Isoniazid
- Pyrazinamide
- Chloramphenicol

FUNCTIONAL RANGE INDICATIONS:

High in:

Dehydration
Erythrocytosis
Polycythemia

Low in:

Functional anemia

References