Nutrition Deficiency Anemia
Anemia that occurs due
to deficiency of a nutritive substance necessary for erythropoiesis is called
nutrition deficiency anemia. The substances which are necessary for erythropoiesis
are iron, proteins and vitamins like C, B12 and folic acid. The
types of nutrition deficiency anemia are:
Iron
deficiency anemia
Iron deficiency anemia
is the most common type of anemia. It develops due to inadequate availability of
iron for hemoglobin synthesis. RBCs
are microcytic and hypochromic.
Causes of iron
deficiency anemia:
i. Loss of blood
ii. Decreased intake of iron
iii. Poor absorption of iron from
intestine
iv. Increased demand for iron in
conditions like growth and pregnancy.
Features of iron deficiency
anemia: Features of iron deficiency anemia are brittle nails, spoonshaped
Nails (koilonychias),
brittle
hair, atrophy of papilla in tongue and dysphagia (difficulty
in swallowing).
Protein
deficiency anemia
Due to deficiency of
proteins, the synthesis of hemoglobin is reduced. The RBCs are macrocytic and
hypochromic.
Pernicious anemia or Addison’s anemia Pernicious anemia is the
anemia due to deficiency of vitamin B12. It is also called Addison’s anemia. It is
due to
atrophy of the gastric mucosa because of autoimmune destruction
of parietal cells. The gastric atrophy results in decreased production of intrinsic
factor and poor absorption of vitamin B12, which is the
maturation factor for RBC. RBCs are larger and immature with almost normal or
slightly low hemoglobin level. Synthesis of hemoglobin is almost normal in this type of
anemia. So, cells
are macrocytic and normochromic/hypochromic. Before knowing the cause of
this anemia, it was very difficult to treat the patients and the disease was considered
to be fatal. So, it was called pernicious anemia. Pernicious anemia is
common in old age and it is more common in females than in males. It is
associated with other autoimmune diseases like disorders of thyroid gland,
Addison’s disease, etc. Characteristic features of this type of
anemia are lemon yellow color of skin (due to anemic paleness and mild jaundice) and red sore tongue.
Neurological disorders such as
paresthesia
(abnormal
sensations like numbness, tingling, burning, etc.), progressive
weakness and
ataxia
(muscular
incoordination) are also observed in extreme conditions.
Megaloblastic anemia
Megaloblastic anemia
is due to the deficiency of another maturation factor called folic acid. Here,
the RBCs are not matured. The DNA synthesis is also
defective, so the nucleus remains immature. The RBCs are megaloblastic and hypochromic. Features of
pernicious anemia appear in megaloblastic
anemia also. However,
neurological disorders may not develop.
4. Aplastic Anemia
Aplastic anemia is due to the disorder
of red bone marrow. Red bone marrow is reduced and replaced
by fatty tissues. Bone
marrow disorder occurs in the following conditions:
i. Repeated exposure to Xray or gamma
ray radiation.
ii. Presence of bacterial toxins,
quinine, gold salts, benzene, radium, etc.
iii. Tuberculosis.
iv. Viral infections like hepatitis
and HIV infections. In aplastic anemia, the RBCs are normocytic and
normochromic.
5. Anemia of
Chronic Diseases
Anemia of chronic diseases is the
second common type of anemia (next to iron deficiency anemia). It is
characterized by
short lifespan of RBCs, caused by disturbance in iron metabolism or resistance
to erythropoietin action. Anemia develops after few months of
sustained disease. RBCs
are normocytic and normochromic. Common causes anemia of chronic diseases:
i. Noninfectious inflammatory
diseases such as
rheumatoid arthritis (chronic inflammatory autoimmune disorder
affecting joints).
ii. Chronic infections like
tuberculosis (infection caused by Mycobacterium tuberculosis) and
abscess (collection of pus in the infected
tissue) in lungs.
iii. Chronic renal
failure, in which the erythropoietin secretion decreases (since erythropoietin is
necessary for the
stimulation of bone marrow to produce RBCs, its deficiency causes anemia).
iv. Neoplastic disorders (abnormal and
disorganized growth in tissue or organ) such as Hodgkin’s
disease
(malignancy
involving lymphocytes) and cancer of lung and breast.
RBCs are generally normocytic and
normochromic in this type of anemia. However, in progressive
disease associated
with iron deficiency the cells become microcytic and hypochromic.
0 Comments