Kwashiorkor — Severe malnutritution in children primarily caused by a protein-poor diet, characterized by growth retardation.
Marasmus — Severe malnutritution in children caused by a diet lacking in calories as well as protein. Marasmus may also be caused by disease and parasitic infection.
Micronutrients — Essential dietary elements that are needed only in very small quantities. Micronutrients are also known as trace elements. They include copper, zinc, selenium, iodine, magnesium, iron, cobalt, and chromium.
[ mal″noo-trish´un ]
poor nourishment resulting from improper diet or from some defect in metabolism that prevents the body from using its food properly. Extreme malnutrition may lead to starvation. Although poverty is still the major cause of malnutrition, the condition is by no means confined to the underdeveloped parts of the world. Anyone can become undernourished by seriously neglecting the diet. A well balanced diet, which varies slightly with a person's age, should include adequate amounts of protein, vitamins, minerals, and carbohydrates. For an explanation of the value of properly balanced diets and guidelines for a healthy diet, see nutrition .
Ignorance of the basic principles of nutrition is probably almost as great a cause of undernourishment as poverty. Misplaced faith in vitamin pills as a substitute for food, for example, can cause undernourishment if carried to extremes. So can over-reliance on excessively processed foods. Modern methods of processing and refining foods can sometimes cause a loss of valuable nutrients, as happens in the refining of certain grains, such as rice. However, this danger is recognized by both the government and the manufacturers who try to retain or restore the nutritional value of many foods. alcoholism. which frequently leads a person to rely on alcohol at the expense of food, is another cause of malnutrition.
People who want to gain or lose weight, or who avoid certain foods, may endanger their health by following an unbalanced diet that lacks essential nutrients. Anyone who plans to follow a special diet should consult with a Registered Dietitian. Malnutrition can also stem from disease. If the organs of the digestive system that transform food into bone, tissue, blood, and energy fail to function properly, the body will not receive adequate nourishment. Such deficiencies can cause certain liver diseases, and some anemias. The endocrine glands and enzymes are also vital to the proper use of food by the body, and defects in their functioning may cause forms of malnutrition.
Symptoms. In general, the symptoms of malnutrition are physical weakness, lassitude, and an increasing sense of detachment from the world. There are also specific symptoms that vary according to the essential substance lacking in the diet. For example, lack of vitamin A can result in night blindness. or poor vision in dim light. In the absence of adequate exposure to sunlight, a lack of vitamin D can cause rickets. which results in malformed limbs in infants and children because the bones fail to harden properly. A lack of vitamin C causes scurvy. with symptoms of bleeding gums and easily bruised skin. Other vitamin deficiency diseases are beriberi and pellagra. If there is not enough iron in the diet, iron deficiency anemia develops. Malnutrition can also result from allergic reactions to foods, as in celiac disease .
In starvation there are signs of multiple vitamin deficiency. There may be edema, abdominal distention, and excessive loss of weight. As starvation progresses, fat cells become small and accumulations of fat are depleted. The liver is reduced in size, the muscles shrivel, and the lymphoid tissue, gonads, and blood deteriorate.