Deficiency Diseases The human body needs a balance of nutrients such as vitamins, minerals and amino acids to carry out body functions. Deficiency diseases occur when substances are not absorbed by the digestive system and therefore can not be used by the body. Scurvy Scurvy is caused by a lack of Vitamin C, or ascorbic acid, scurvy usually appears in adults after six months without vitamin C. It causes spongy and inflamed gums, loose teeth, swollen and tender joints and increasing levels of weakness. Often the tissues of blood from broken blood vessels are reabsorbed, causing anaemia due to the lack of iron. It also causes the body to reduce the production of materials within cells that support tissues and form cement like substances in capillaries, bone and cartilage. Scurvy caused huge problems in sailors who spent months at sea without any fresh vegetables to provide vitamin C. It was usually fatal, forcing the navy to give lime juice to all navel vessels in an effort to reduce deaths. Oranges and lemons have a higher vitamin C content than limes, and were also used successfully by the navy. Soon after the introduction of citrus fruits the number of deaths dropped and today scurvy is not a common problem. Rickets Rickets is caused by the decreased level of the mineral hydroxyapatite in the bones and cartilage due to low levels of phosphorus and calcium found in the bloodstream. Vitamin D is vital in maintaining the levels of both calcium and phosphorus and is often the cause of rickets. This can be caused by a direct lack of vitamin D in the diet or lack of ultraviolet radiation from direct sunlight which prevents the element 7-dehydrocholesterol from converting into vitamin D. Often found in children, it is characterised by the underdevelopment of bones, which do not harden. This results in mild to severe skeletal deformities, with children being the most at risk due to the fact that their bones are just developing. Today rickets is rarely seen in the developed world, although it can be found in countries with low levels of nutrition. Beriberi There are two main forms of beriberi, which is caused by lack of Vitamin B1. When there is a low calorie intake and high levels of inactivity beriberi tends to affect the central nervous system. This is known as dry beriberi and can eventually lead to paralysis. Less serious cases result in poor coordination and the tightening of muscles. The second form, known as wet beriberi, is linked with very high activity levels and eating large amounts of carbohydrates. Symptoms include sweating, high heart rates and warm skin which if not treated lead to heart failure and death. Extremely high levels of B1 deficiency can lead to less blood flow into the brain, a condition called Wernicke-Korsakoff syndrome. This can cause confusion and involuntary movements of the eyes, which if untreated leads to coma and eventual death. Beriberi is uncommon in developed western countries, most often found where a main portion of the diet consists of rice, which is not able to provide the vitamin B1 necessary for body functions. In about 50% of cases there is a complete recovery when vitamin B1 is added to the diet. Pellagra Pellagra is caused by the lack of niacin, found in Vitamin B, either through inadequate intake or absorption causes pellagra. The first symptoms include weakness, weight loss and being unable to sleep. Exposed skin on the back of the neck, arms, hands, feet and legs will become rough, turn red and scaly after being in sunlight, and painful lesions will develop in the mouth. It also effects the gastrointestinal tract, with loss of appetite, indigestion and diarrohea. As the disease progresses it begins to alter the nervous system through headaches, vertigo, aches, unbalanced mental condition and tremors in the muscles. Pellagra is found around the world, although it is no longer as common in countries such as the United States where vitamin B has been added to processed wheat. It is found in people whose diet lacks proteins, particularly those who eat large amounts of corn. It is also found in people with gastrointestinal diseases who are unable to absorb vitamins. Pellagra is treated by increasing the levels of niacin and other B-complex vitamins and can be easily prevented with a diet rich in vegetables, milk, lean meat or fish and whole grain cereals.

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