7. Iron
• Iron is absorbed all over the intestine.
• Absorbed
– Directly
– At luminal membrane- divalent metal transporter1(DMT1)
– Basolateral membrane – ferroportin (FP)
• Iron is distributed
– as haemoglobin in erythrocytes
– Stored as ferritin and haemosiderin in liver spleen bone marrow
– as myoglobin in muscles
– as parenchymal iron in reticuloendothelial cells
– as transferrin which are iron
-binding blood plasma glycoprotein
8. Factors impeding iron absorption
Antacids
Egg
Phytates (in maize and wheat)
Tetracyclines
Presence of other foods in the stomach
Mucosal block (ferritin curtain)
– the gut has a mechanism of preventing entry of excess iron in the body
9.
10. Effects of deficiency
• Megaloblastic anaemia
• Spina bifida of the foetus in case of pregnant women
Adverse effects:
• Allergy
• Anaphylaxis
11.
12. Vitamin B12 :
Cyanocobalamin and hydrocobalamine
– referred to as vit B12
Vit B12 is intricately linked to folate metabolism
Involved in protein synthesis
Involved in DNA production
Involved carbohydrate and lipid metabolism
Is utilised in thymidylate synthesis
13. Vitamin B12
required for the
• the conversion of homocysteine to methionine
• conversion of methylmalonyl-CoA to succinyl CoA
• interconversion of leucine and beta leucine
Manifestations of deficiency :
• Megaloblastic anaemia
• Epithelial damage
• Neural tube defect
• General weakness
14.
15.
16. Folic Acid
• Source:
liver, cereals, nuts, green vegetables
Pharmacokinetics:
• Administered through oral or parenteral routes.
• Absorbed from the proximal jejunum.
• Widely distributed and stored in the liver
Function of Folic acid—
• It is the parent compound of folates
• folates act as a cofactor in the formation of purine and pyrimidine
– which is essential for DNA synthesis. Folate cofactor is also needed
in the formation of thymidylic acid.
17. Uses of vitamin B12 and folic acid
Megaloblastic anaemia:
Nutrtional folate deficiency
Increased demand-pregnancy, lactation, infancy, severe iron
deficiency
Pernicious anaemia (folate deficiency)
Malabsorption syndrome- tropical sprue coeliac disease,
Antiepileptic therapy causes megaloblastic anaemia
Prophylaxis of folate deficiency
Methotrexate toxicity are countered
