Nutritional Anaemias

Question 1

Define anaemia

Answer 1

Anaemia is a condition characterised by a deficiency of red blood cells or of haemoglobin in the blood.

This deficiency results in a decreased oxygen-carrying capacity of the blood, leading to reduced oxygen supply to the body’s tissues and organs

Haemoglobin is the protein in red blood cells that carries oxygen from the lungs to the rest of the body

Diagnostic criteria for anaemia typically involve haemoglobin levels below certain thresholds: for men, these levels are typically less than 13.5 gram/100 ml, and for women, they are less than 12.0 gram/100 m

The causes of anaemia are diverse and can include nutritional deficiencies (such as iron, vitamin B12, or folate deficiency), hereditary disorders (like sickle cell anaemia or thalassemia), bone marrow disorders, chronic diseases (such as kidney disease or cancer)

Question 2

Describe causes of anaemia

Answer 2

1) Increased loss of RBCs from blood loss:

• Can be due to bleeding, from trauma, surgery, gastrointestinal bleeding (ulcers, colon cancer, haemorrhoids), heavy menstrual bleeding

2) Decreased production of RBCs:

• Nutritional deficiencies: Deficiency of iron, vitamin B12, or folate can lead to anaemia
• Bone marrow disorders: Diseases like leukaemia, myelodysplastic syndromes, aplastic anaemia, or bone marrow damage from chemotherapy or radiation can result in decreased production of RBCs
• Chronic diseases: Chronic diseases like kidney disease, cancer, rheumatoid arthritis, etc., can suppress the production of RBCs. Kidney disease specifically can result in decreased production of erythropoietin, a hormone that stimulates RBC production
• Genetic conditions: Conditions like thalassemia or sickle cell disease can result in decreased RBC production or increased destruction

3) Increased destruction of RBCs (Hemolytic anaemia):

• could be due to conditions like autoimmune diseases, genetic disorders like sickle cell disease and thalassemia, infections, certain drugs

Question 3

Explain the implications of iron deficiency

Answer 3

1) Anaemia:

• Iron is an essential component of haemoglobin, a protein in red blood cells that carries oxygen from the lungs to the rest of the body
• Iron is an essential component of haemoglobin, a protein in red blood cells that carries oxygen from the lungs to the rest of the body

2) Impaired Immune Function:

• Iron is involved in the immune response, particularly in the proliferation and maturation of lymphocytes and the production of cytokines

3) Neurodevelopmental effects on children:

Question 4

Understand causes and complications of folate and B12 deficiency

Answer 4

Cause of Folate and B12 Deficiency:

1) Dietary Deficiency:

• Insufficient intake of foods rich in these vitamins can cause deficiency

2) Malabsorption:

• Conditions affecting the stomach or intestines can impair absorption of these vitamins
• For B12, a specific protein called intrinsic factor, secreted by cells in the stomach, is necessary for its absorption
• Diseases such as pernicious anaemia, where the body attacks these cells, or surgical removal of part of the stomach can cause B12 deficiency
• Celiac disease or inflammatory bowel disease can cause folate deficiency

3) Increased Requirement:

• Pregnancy, lactation, and certain chronic diseases can increase the body’s requirement for these vitamins

4) Drug-Induced:

• Certain drugs like methotrexate, phenytoin, sulfasalazine, or certain antibiotics can interfere with the body’s use of folate
• Long-term use of antacids and type 2 diabetes drugs can affect B12 absorption

Complications of Folate and B12 Deficiency:

1) Megaloblastic Anaemia:

• The lack of these vitamins disrupts DNA synthesis, causing red blood cells to enlarge and divide improperly, leading to anaemia
• Symptoms include fatigue, weakness, pale skin, shortness of breath, and palpitations

2) Neurological Problems:

• B12 deficiency can also lead to neurological problems such as numbness, tingling in hands and feet, balance problems, depression, confusion, dementia, and memory loss

3) Hyperhomocysteinemia:

• Both deficiencies can lead to elevated levels of homocysteine, an amino acid in your blood, increasing the risk of heart disease and stroke

4) Pregnancy Complications:

• Folate deficiency is linked with neural tube defects, premature birth and low birth weight