In the early part of the 20th century before any knowledge of the vital role vitamins played in nutrition, there were many diseases caused by vitamin deficiencies. The diseases commonly occurred among the poorer people, and were associated with being caused by infections rather than associated with any lack of nutrition.
The disease known as pellagra was extremely common. This disease shows as red blotches on the skin, diarrhea, and often affects the central nervous system leading to mental confusion. Scientists at the time had noticed that any person eating a good diet consisting of meat, vegetables, and dairy products were often in good health and with the advent of the discovery of the vital role vitamins played in the diet, it was soon learned, just prior to WW2 that the substance niacin (now known to be a vitamin B complex) both prevented and cured pellagra
Niacin was found to be present in flour, bread and cornmeal which were certainly more affordable for the poor people, and it was then recognized to be caused by a deficiency in vitamins, rather than being caused by any infection and the disease was virtually eliminated.
There are a variety of other diseases which result
from vitamin deficiency
In some areas of Africa and Eastern Asia a form of night blindness accompanied by rough skin is a common symptom of vitamin deficiency, especially vitamin A. This vitamin is found in fish and dairy products not often included in the diet of poorer people.
Anemia is another disease associated with vitamin deficiency, it is a blood condition whereby too few red blood cells are produced or they are deficient in hemoglobin content. The main cause of anemia is lack of vitamins and lack of iron in the diet, and inevitably can lead to poor overall health. Iron can be obtained from including leafy vegetables such as cabbage in the diet or taking an iron tablet supplement.
The disease known commonly as goiter is a further sign of vitamin deficiency. Goiter is the swelling of the thyroid gland and shows as an enlargement at the front of the neck, and is usually associated with an iodine deficiency.
Dwarfism is another disease which is now recognized as being directly attributable to a nutritional deficiency primarily due to the lack of the mineral Zinc.
Since the importance of both vitamins and minerals has been recognized in the human diet, many of these diseases have been eliminated from the richer countries, but are still present to a lesser degree in poorer nations and totally underdeveloped areas. Now that the connection has been firmly established between certain chemicals in our food and our health, most people now enjoy a well balanced diet. This can readily be observed along with advances made in the medical field, in the increase in size and reduced death rate among children in most Western societies.