Iron - Essential to our life

Haemoglobin is a metalloprotein in the red blood cells and makes the red blood cells "red". Haemoglobin contains iron. Its function is to transport oxygen from lung to tissues in our body.Anaemia is the condition which we have low haemoglobin.

Without healthy red blood cells, our body cannot get enough oxygen and we become fatigued,
 
As iron is an essential component to make haemoglobin, we have to ensure we can take up enough iron from our diet.

There are two types of iron in food: haem iron which is mainly found in meat (e.g., beef, mutton) and non-haem iron which is found in plants (e.g., leafy green vegetables, grains, bean and nuts). The haem iron can be absorbed more easily by the body than non-haem iron. And so for vegetarian, selection of iron-rich plants is especially important.

Vitamin C enhances iron absorption (for example, an orange contains 50 mg vitamin C which enhances iron absorption by 2 to 3 times).

 

On the other hand, caffeine interferes with the body’s absorption of iron.

 

The following shows the iron content (in mg) based on 100 grams of cooked food:

Haem Iron

• Beef (2.8)
• Mutton (2.7)
• Pork (1.3)
• Dried shrimp (11.0)
• Oyster (10.2)
• Clam (14.4)
• Pork liver (17.0)

Non-haem Iron

• Black bean (7.2)
• Red bean (3.1)
• Sesame (10.4)
• Soybean stick (16.5)
• Agaric (46.0)
• Whole-wheat cereals (12.0)
• Cornflakes (6.7)
• Instant oatmeal (3.8)

However, even we have taken up enough iron, we might still suffer from haemolysis. In this case, the life of red blood cells would be shorter than the normal 120 days. When the bone marrow fails to produce enough red blood cells in time, it can lead to haemolytic anemia. This is due to "G6PD deficiency" in our body.

Our body produces G6PD which is an enzyme that promotes glucose oxidation process. During the process, a by-product NADPH produced. This is an antioxidant which helps cell membrane of red blood cells being stable. If our body cannot produce enough G6PD due to heredity, the amount of NADPH reduces. And the red blood cells are easy to be oxidized and haemolysis occurs.