The function of iron in the human body is of the highest importance. Iron is used by the body in carrying the oxygen from the lungs to the tissues, where the processes of nutrition are carried to completion, and the waste substances so dangerous to life are oxidized. The hemoglobin (red coloring matter of the blood), like the chlorophyll (green coloring matter in plants), is dependent on iron for its existence. Concerning the importance of a proper supply of food iron, Professor Sherman says:
“There is no considerable reserve store of relatively inactive iron in the body corresponding to the store of calcium and phosphorus in the bones. Hence if the intake of iron fails to equal the output, there must soon result a diminution of haemoglobin, which if continued, must mean a greater or less degree of anaemia.” “Chemistry of Food and Nutrition,” page 285.
According to Graham Lusk,’ ordinary white flour contains only 1.5 milligrams of iron in 100 grams of fresh substance, as against 5.2 milligrams in the same quantity of entire wheat flour; white flour contains only 146 milligrams of potassium and 86 of phosphorus, as against 515 milligrams of potassium and 469 of phosphorus in the same quantity of entire wheat flour.
When iron is lacking in the food, and consequently in the blood, the color vanishes from the cheeks. Iron deficiency baffles many, even physicians, who often fail to see an abundant supply of it at their very doors. The most prolific sources of food iron are the well-known greens, spinach, beet greens, dandelion greens, lettuce, succulent vegetables, and many fruits, especially strawberries and prunes.