Vitamin B12 deficiency anemia

Description of the disease

This is anemia, developed due to impaired DNA synthesis in the cell nucleus. A deficiency of vitamin B12 and/or folic acid causes this disorder. Meanwhile, in the bone marrow, ineffective erythropoiesis reduces the production of erythrocytes (red blood cells responsible for oxygen transport), leading to cell disintegration before they leave the bone marrow.

The prevalence of this form of anemia is 9 cases per 100,000 population per year.

Vit.B12 is not synthesized in the body and must be obtained from food. The daily dose is 5 mg. Liver reserves are about 2mg, which would be enough for 6 years. The daily dose of folic acid is 100 mg, during pregnancy – 400 mg. Liver reserves of folic acid are not replenished, which would last for up to 3 months.

Vitamin B12 deficiency anemia develops due to strict vegetarianism, impaired vit.B12 absorption due to partial removal of the stomach, lack of intrinsic Castle factor (found in the stomach), corrosive gastritis, intestinal pathology (e.g., resection of the small intestine, presence of a parasite – tapeworm). Also, this vitamin deficiency occurs during pregnancy, in cases of hyperthyroidism, and in the development of malignant tumors.

Folic acid deficiency occurs due to low intake of folates in the diet (in alcoholics, elderly people), partial removal of the intestine, fistula, diverticula, strictures, Crohn’s disease, amyloidosis, lymphoma, etc. Also, due to the use of certain medications (oral contraceptives), congenital folate malabsorption. During pregnancy, in infants, children, adolescents, when taking methotrexate, biseptol, the consumption of folates is greatly increased, leading to their deficiency.

Symptoms

Gradual Onset

Clinical symptoms usually manifest gradually, sometimes several years pass from the onset of symptoms to the diagnosis.

Main Symptoms

• Fatigue
• Decreased work capacity
• Pallor
• Skin resembling straw color (resembles coffee with milk color)
• Vitiligo
• Tongue changes: smooth and red tongue
• Decreased appetite
• Disturbed taste sensation
• Tingling sensation
• Discomfort in the epigastrium
• Heartburn
• Possible vomiting
• Abdominal bloating
• Intermittent abdominal pain

Neurological Symptoms

• Tingling and numbness (often in the toes, later in the feet and hands)
• Sensory disturbances
• Unresponsive and heavy legs
• Stumbling and uncoordinated gait (“swaying” to the sides)
• Weakness in limbs
• Partial paralysis in late stages

Diagnosis

Important medical history (whether there is alcoholism), presenting symptoms. Doctors perform blood tests, noting a decrease in hemoglobin, hematocrit, and red blood cell count, while iron levels, LDH, and indirect bilirubin concentration in the blood serum increase. Under a microscope, they observe characteristic signs of erythrocyte morphology. In the bone marrow – stem cells remain unchanged, and the production of blood cells is inefficient, the amount of sideroblasts increases, iron accumulates in bone marrow macrophages.

Additional tests are always necessary to help determine the cause of anemia.

Treatment

Eliminate the cause of anemia. Doctors prescribe intravenous vitamin B12 and folic acid preparations. They also recommend a balanced diet and prohibit alcohol consumption.

Source | Author Doctor Nikas Samuolis, reviewed by Prof. Virginijus Šapoka | Vilnius University | Faculty of Medicine | Head of the Department of Internal Medicine, Family Medicine, and Oncology