Anemia, often manifested as pallor, dizziness, weakness, tinnitus, etc. The severity of symptoms is not only related to the degree of anemia, but also to the speed of its onset. If a person has the above symptoms and goes to the hospital for a routine blood test and is found to have severe anemia (hematocrit below 60 g/L), this often suggests a chronic development of anemia, rather than a recent occurrence.
The main raw materials for the production of red blood cells, besides iron, are folic acid and vitamin B12, and the general term nutritional anemia refers to iron deficiency anemia and megaloblastic anemia.
Whether the body is deficient in folic acid and/or vitamin B12 can be determined by testing blood folic acid and/or vitamin B12 levels, but the level of testing is often affected by a number of factors.
Folic acid
It is a B vitamin, rich in fresh fruits, vegetables and meat foods. More than 50% of folic acid in food is lost after long cooking. The amount of folic acid stored in human body is 5 – 20mg, nearly half of which is in the liver; the amount of folic acid excreted with feces is about 2 – 5ug per day; folic acid is mainly absorbed in the duodenum and proximal jejunum, the daily requirement of the body is less, and it needs to be taken from food 200ug.
The main causes of folic acid deficiency are
1, reduced intake due to partial diet or improper processing.
2, increased need for infants, adolescents and pregnant women as well as those suffering from other diseases such as hyperthyroidism, chronic infections, tumors, etc.
3, intestinal diseases affecting absorption.
4, impaired utilization of folic acid due to the effects of certain drugs or congenital defects
5, hemodialysis, alcoholism can lead to increased excretion of folic acid.
Vitamin B12
Vitamin B12 is stored in the human body in the amount of 2 – 5mg, mainly in the liver, normal people need 1ug daily, mainly from animal liver, kidney, meat, fish, eggs and dairy products and other foods. Vitamin B12 combines with the internal factors of the epithelial cells of the gastric mucosa so that it is not destroyed by the secretion of the gastrointestinal tract and reaches the end of the ileum to be absorbed into the intestinal epithelial cells and then enters the liver via the portal vein.
Causes of vitamin B12 deficiency include reduced intake, impaired absorption, and impaired utilization.
Clinical manifestations.
Anemia, and in severe cases, whole blood cytopenia, recurrent infections and the presence of, in a few patients, mild jaundice.
Oral mucosa, tongue papillae atrophy, tongue “beef-like tongue”, may be accompanied by tongue pain; other nausea, abdominal distension, diarrhea or constipation.
Neurological and psychiatric abnormalities, such as symmetrical distal limb numbness, profound sensory disorders, ataxia or gait instability; irritability, paranoia, depression, insomnia and psychosis.
Laboratory tests
Routine blood tests: macrocytic anemia, or in severe cases, complete cytopenia; excessive neutrophil lobarization (5-lobed nuclei accounting for more than 5%, or the presence of 6-lobed nuclei or more), or giant rod-shaped nucleated granulocytes.
Bone marrow: young nuclei, old plasma, and megaloblasts.
Serum vitamin B12 is less than 74 pmol/L (100 ng/ml), serum folate is less than 6.8 nmol/L (3 ng/ml), and erythrocyte folate is less than 227 nmol/L (100 ng/ml).