Nutrient Deficiency Diseases
Nutrient Deficiency Diseases
Mineral deficiency diseases
Nutrient deficiency diseases occur when there is an absence of nutrients which are essential for growth and health. Lack of food leading to either malnutrition or starvation gives rise to these diseases. Another cause for a deficiency disease may be due to a structural or biological imbalance in the individual’s metabolic system.
There are more than 50 known nutrients in food. Nutrients enable body tissues to grow and maintain themselves. They contribute to the energy requirements of the individual organism and they regulate the processes of the body. Carbohydrates, fats, and proteins provide the body with energy. The energy producing component of food is measured in calories. Aside from the water and fiber content of food, which are also important for their role in nutrition, the nutrients that serve functions other than energy production can be classified into four different groups: vitamins, fats, proteins, and minerals. All are necessary for proper body function and survival.
Polish-born Casimir Funk (1884-1967) originated the word vitamin in 1912, spelling it as vitamine, because he thought they were part of a group of organic compounds containing nitrogen, called amines. The final -e was later dropped in 1920 at the suggestion of the English nutritionist Jack Cecil Drummond who pointed out that these trace-like substances found only in food and essential for good health were not always amines. By 1914 Funk theorized that beriberi, scurvy, and pellagra were caused by a vitamin deficiency.
Scurvy is one of the oldest vitamin deficiency diseases recorded and the first one to be cured by adding a vitamin to the diet. Scurvy was a common malady of sailors of the age of exploration of the New World. It has been recorded that Vasco da Gama was supposed to have lost half of his crew to scurvy in his journey around the Cape of Good Hope at the end of the fifteenth century and Richard Hawkins reported that he lost 10,000 sailors from the disease a century later.
The main symptom of scurvy is hemorrhaging. Hemorrhage marks appear as spots under the skin or bruises, given the medical terms of petechiae and ecchymoses. The gums are swollen and usually become infected (gingivitis). Bleeding can take place in the membranes covering the large bones as well as in the membranes of the heart and brain. Wounds heal slowly and the bleeding in or around vital organs can be fatal. The disease is slow to develop and is manifested early by fatigue, irritability, and depression.
In 1747 a British naval physician, James Lind, in a response to a an outbreak of scurvy conducted a controlled experiment. He took 12 of the sailors who had developed scurvy and divided them up into six groups and gave each pair different medicines such as nutmeg, cider, seawater, and vinegar, while others were given lemons or oranges. The two men given the oranges and lemons both completely recovered in about a week after the experiment.
His Treatise of the Scurvy published in 1753 is the first example of a controlled clinical trial experiment. In his treatise, Lind gave a thorough review of other authors who had written on scurvy along with a careful clinical description of the condition. It was not until the end of the eighteenth century that the British navy finally had its sailors drink a daily portion of lime or lemon juice to prevent scurvy.
Vitamin C (ascorbic acid) is necessary for collagen formation, which is the protein component of connective tissue, strong blood vessels, healthy skin and gums, formation of red blood cells, wound healing, and the absorption of iron. In addition to scurvy, other scurvy-like conditions can develop from a deficiency of vitamin C, such as adult acne, easy bruising, sore gums, and hemorrhages around bones. Good sources for vitamin C are citrus fruit, broccoli, strawberries, cantaloupe, and other fruits and vegetables.
Discovering the causes for beriberi became part of the history of discovering vitamins. Christian Eijkman (1858-1930) was a Dutch physician who was a member of a government commission sent to the East Indies in the 1880s to study the disease beriberi, which was prevalent in southeast Asia, where the main diet is comprised of unenriched rice and wheat.
There are three forms of this disease: infantile beriberi, wet beriberi, and dry beriberi. Infantile beriberi occurs when a mother who breast feeds her child is lacking vitamin B1 thiamine. The mother who nurses the child may not manifest the disease, but the deficiency occurs through the breast feeding and the child usually dies after the fifth month. In the childhood and adult versions of the disease there is a preliminary condition of fatigue, loss of appetite, and a numb tingling feeling in the legs. This condition can then lead to either wet or dry beriberi.
In wet beriberi there is an accumulation of fluid throughout the body and a rapid heart rate that can lead to sudden death. In dry beriberi there is no fluid swelling, but there is a loss of sensation and a weakness in the legs. The patient first needs to walk with the aid of a stick and then becomes bedridden and easy prey to an infectious disease.
In Eijkman’s laboratory he noticed that some of the fowl he was experimenting with developed paralysis and polyneuritis, as in the dry form of beriberi. The director of the hospital forbade Eijkman from feeding these birds with table scraps which consisted mainly of polished rice. He therefore began to feed them with whole rice, after which he noticed that they regained their movement and there was no recurrence of paralysis.
The idea that the birds had some form of beriberi was rejected by Eijkman’s colleagues. His explanation for the cure was that the polished rice had some toxin in it which the unpolished rice did not have. This explanation was rejected by a fellow researcher, Gerrit Grijns (1865-1944), who also stayed on to study the disease after the commission had already left. He found that when the chickens were taken off the rice diet completely and feed with meat instead, they did not develop the characteristic paralysis, but if the meat were overcooked, then the condition would reappear. In 1901 Grijns showed that beriberi could be cured by putting the rice polishings back into the rice.
Vitamin B1 (thiamine) prevents the disease or symptoms of beriberi. Food sources for this vitamin are meats, wheat germ, whole grain and enriched bread, legumes, peanuts, peanut butter, and nuts.
Pellagra is a vitamin deficiency disease associated with poverty. The symptoms of pellagra are referred to as the “three D’s”: diarrhea, dermatitis, and dementia. If disease is not treated it may lead to death. Gaspar Casal (c. 1691-1759) was the first to publish a thorough explanation of pellagra in 1762 after his death. He studied and wrote about the disease which he observed in a region of Spain where it was called “mal de la rosa,” because of the reddened dermatitis which appeared around the back of the neck. Even though the belief of his time was the disease was caused by an infection, Casal believed origins were from inadequate nutrition.
The popular belief that pellagra was caused by infection lasted from the sixteenth century to the early twentieth century until Joseph Goldberger (1881-1929) a member of the United States Public Health Service studied the high numbers of cases in the southern United States. Goldberger established that pellagra was caused by an insufficient amount of niacin (vitamin B3) also known as nicotinic acid and the active form of niacin that the body uses called niacinamide.
Rickets is a bone disease deficiency caused by a lack of vitamin D, called the “sunshine” vitamin because it is the only vitamin that can be produced by the effects of sunlight on the skin. It was a common disease of infants and children, but since all milk and infant formulas have vitamin D added to them, it is rarely seen today. In rickets, legs will become bowed by the weight of the body and the wrists and ankles are thickened. The teeth are badly affected and take a longer time to come in. All the bones are affected by not having sufficient calcium and phosphorous for their growth and development. Lack of exposure to sunlight, which helps to produce vitamin D, is a major cause for childhood rickets. Crowded slum conditions in areas where there was little or no sunlight were responsible for its appearance in the earlier stages of the industrial revolution.
An adult version of rickets caused by a deficiency of vitamin D, calcium, and phosphorous is called osteomalacia. The bones become soft and deformed and there is rheumatic pain. The disease is observed in the Middle East and Asia more so than in western countries. The way to prevent rickets and other bone diseases such as osteoporosis is a combination of calcium, phosphorous, and vitamin D.
Night blindness or the difficulty of seeing in dim light is caused by a deficiency in vitamin A which helps in the formation of visual purple needed by the eyes for night vision. The deficiency can also cause glare blindness when the eye is either exposed to too much light or a sudden change in the amount of light when entering a darkened room. Another eye disease caused by vitamin A deficiency is xerophthalmia which can lead to blindness. This condition affects the cells of the cornea, other eye tissues, and the tear ducts, which stop secreting.
Vitamin A deficiency can create a number of adverse skin conditions, problems with tasting and smelling, and it may also cause difficulties with the reproductive system.
Vitamin E and K deficiencies are rare. Vitamin E protects against substances that oxidize quickly and vitamin K promotes normal blood clotting. Vitamin B12 (cobalamin) provides protection against pernicious anemia and mental disturbances. Vitamin B 6can also protect against anemia as well as dermatitis, irritability, and convulsions.
Mineral deficiency diseases
There are about 25 mineral elements in the body usually appearing in the form of simple salts. Those which appear in large amounts are called macro minerals while those that are in small or trace amounts are micro minerals. Some that are essential are calcium, phosphorous, cobalt, copper, fluorine, iodine, iron, sodium, chromium, and tin. Aluminum, lead, and mercury are not as essential.
Iodine is necessary for the proper functioning of the thyroid gland which controls the body’s basal metabolism rate through its production of two hormones, thyroxine, and triiodinethyronine. Without a sufficient amount of iodine in the diet the gland begins to enlarge its cells in its efforts to produce the hormone, thus producing a goiter, which is a swelling around the neck. Certain regions lack iodine in the soil which leads to cretinism, the physical and mental development of an infant passed on from the lack of iodine in the mother’s diet.
Protein (amino acid) deficiencies
Proteins are needed in the body for amino acids. Proteins are broken down in the digestive system to form amino acids which are then absorbed by the rest of the body to form new proteins in the form of vital body tissues such as muscle, connective tissue, and skin. There are two types of protein, fibrous and globular proteins. Fibrous protein is insoluble and goes into making the structural tissues of the body. Globular protein forms amino acids that become enzymes and hormones and other vital parts of cellular functioning within the body.
Adults rarely suffer from protein deficiency diseases unless there is an impairment in the intestinal tract, but in countries plagued by insufficient food children will develop protein deficiency diseases that lead to very high mortality rates.
A specific wasting away disease caused by protein deficiency in third world countries that lack adequate food supplies is called kwashiorkor. It is a word which describes the condition of an infant who has to be weaned away after a year to make room for the next baby. The weaning food, which is mainly sugar and water or a starchy gruel lacks protein or has a poor quality of protein. The weaning diet for these young children leads to other nutrient deficiency diseases as well.
Symptoms of kwashiorkor are apathy, muscular wasting, and edema. Both the hair and the skin lose their pigmentation. The skin becomes scaly and there is diarrhea and anemia, and permanent blindness can result from this condition. Marasmus is another condition of a wasting away of the body tissues from the lack of calories as well as protein in the diet. In marasmus the child is fretful rather than apathetic and is skinny rather than swollen with edema. Aside from contrasting symptoms between the two diseases, there may be converging symptoms which would be described as marasmic kwashiorkor.
There is a wide variation of deficiencies between energy and protein deficient diseases as in the cases described by marasmus and kwashiorkor. The term protein-energy malnutrition (PEM) is used to describe those differences. PEM is the result of poverty as well inadequate information on diet. In some countries there is the mistaken belief that the child should not be given high protein food, which is served to the father, while the child drinks the fluid the meat was cooked in.
In cases of severe PEM it is necessary to hospitalize the child and to administer antibiotics to prevent infections which accompany the condition. Diets rich in protein should be continued after hospitalization, using skimmed milk powder for an energy basis. Legumes (beans) and fish meal are also good sources for protein. Social and political problems have to be managed to allow relief workers to help and to provide an ongoing source of food preparations that can be consumed for adequate nourishment by those in need.
The amounts of most nutrients, especially vitamins, needed to both prevent and treat deficiency diseases are small. The average intake of 1mg of vitamin B1 is sufficient to prevent a deficiency disease of that vitamin, while 10mg of B1 could cure an advanced case of someone about to die of beriberi. Although small doses of vitamins cure deficiencies, large doses of some vitamins such as A and D can be harmful since these two vitamins are already stored by the liver. Vitamins A and D are fat soluble vitamins and can accumulate to the point of becoming toxic. Most other vitamins are water soluble and are excreted in the urine throughout the day.
Most nutritionists insist on a well-balanced diet consisting of the major food substances as an effective and economical way of obtaining nutrients for health. On the other hand, advocates of health food stores maintain that the FDA’s required daily allowances (RDAs) for nutrients are much too low and that cultivation of much of our food supply and its preparation robs our diet of much of its nutrient value.
The American Dietetic Association (ADA) recommends that nutrient needs should come from a variety of foods taken from different dietary sources rather than self-prescribed vitamin supplementation. In order to avoid either the problem of nutrient deficiencies or excesses they recommend that physicians or licensed dieticians should be the source of prescribing supplementation.
The ADA, however, does make allowances for supplement usage under the following conditions: Iron supplements may be required by women when there is excessive menstrual bleeding. Pregnant and breast-feeding women need supplements, especially iron, folic acid, and calcium. People who are dieting and are therefore are on very low calorie diets may require supplementation if they are not getting the right amount of the nutrients they need. Vegetarians may need boosts of vitamin B-12, calcium, iron, and zinc. Newborns are sometimes given vitamin K to prevent abnormal bleeding. Those people who have diagonsised disorders or diseases or are being treated with medications which affects the absorption or metabolism of the nutrient may require supplementation.
Calcium —An essential macro mineral necessary for bone formation and other metabolic functions.
Controlled experiment —Also called a controlled trial. The dividing into groups of experimental subjects to see what the effects of a drug will be when tested along with a dummy drug or placebo (a drug other than the one being tested).
Dermatitis —An inflammation of the skin. A symptom of vitamin deficiency.
Edema —An abnormal collection of fluids in the body tissues. One of the forms of the disease beriberi called wet beriberi.
Essential nutrients —Those nutrients that must be obtained from food for good health and to prevent nutrient deficiency diseases.
Iodine —A mineral necessary for the proper functioning of the thyroid gland.
Niacin —An essential B vitamin needed to prevent pellagra.
Night blindness —Inability to see at night due to a vitamin A deficiency.
Research using 22,000 physicians under the supervision of the Department of Medicine at Harvard is studying the long-term effects of beta carotene (vitamin A) in lowering the incidence of cancer and boosting resistance to infection. It is also being studied in the treatment of AIDS. Beta carotene is a safer version of vitamin A than the preformed oil form called retinol. It is found in carrots, sweet potatoes, broccoli, spinach, collards, turnip greens, kale, and many other vegetables that.
Vitamin C, also known as ascorbic acid, is used as a supplement by more people than any other supplement. Its popularity is due to the work of the two-time Nobel laureate, Linus Pauling who maintained that vitamin C was effective in preventing and lessening the effect of colds and in the treatment of cancer. Pauling’s vitamin C program called for megadoses that far exceeded the government’s RDA recommendations. Pauling recommended a daily dose of between 2,000 and 9,000 milligrams (mg). The National Research Council recommends 60 mg for adult daily and 100 mg for smokers.
The discovery of micro nutrition was made in the early twentieth century as a result of finding the cure for certain diseases, the nutrient deficiency diseases such as scurvy, beriberi, and pellagra. The new dimensions of fully understanding and using our knowledge of nutrients remain to be established from the ongoing research in this area of nutritional science.
Encyclopedia of Human Nutrition, edited by Benjamin Caballero, et al. London: Academic Press, 2005.
Hendler, Sheldon S. The Doctor’s Vitamin and Mineral Encyclopedia. New York: Simon and Schuster, 1990.
Kok, Frans J., et al. Introduction to Human Nutrition. Oxford: Blackwell Publishing, 2002.
Williams, Sue R. Nutrition and Diet Therapy. Boston: Mosby College Publishing, 1989.
Jordan P. Richman