Iron is found in two forms; iron from animal sources called heme iron and iron from plant sources called non-heme iron. Vegetarians are generally at a risk of iron deficiency as the human body does not absorb non-heme iron that well. When a person suffers from iron deficiency or anemia, there are symptoms of fatigue, brittle nails, constipation, paling of lower eyelids, palms and nails, headaches and an inflamed tongue.

Growing children, menstruation, pregnancy and people suffering from parasitic diseases like malaria and hookworms tend to suffer from anemia. Even too much of physical activity makes a person anemic where one may feel colder and take a longer time to warm up as the body produces fewer low thyroid hormones which are heat regulators.

The best way to find out if you suffer from iron deficiency is through the testing of blood samples. The serum iron tests help to check the level of iron in the blood while the ferritin level test helps to find out the capacity of the body in storing iron in the body. This test is very effective in finding out the iron level of the body. On the contrary, too much of iron absorption in the body, called hemochromatosis, tends to cause chronic tiredness in the person. This is why it is always better to check the iron level in the body before starting on an iron supplement.

Iron in the natural form and as a supplement is absorbed from the gastro intestinal tract. However, the limit of absorption of iron depends on the requirement of iron by the person. A person needs more iron in growing periods, when suffering from anemia, during menstruation and pregnancy and during hemorrhage. It is usually the inorganic form of ferric that is found in food that converts into organic ferrous for better absorption.