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'Vitamin deficiency disease' can be defined as "the consequence of dearth in a particular vitamin in the body in required amounts for healthy bodily function".Causes of vitamin deficiency
Various biochemical processes are required for the smooth functioning of the body. They are brought about by the vitamins. Basically vitamins can be divided into water-soluble and fat-soluble vitamins. Excess of fat-soluble vitamins are stored in the body. However most of the water soluble vitamins, when in excess, are excreted from the body. Hence they are required to be taken in the diet on a daily basis.Malnutrition and malabsorption are the main causes of the dearth. The deficiency of vitamin may be primary or secondary. The primary deficiency occurs when there is paucity of the vitamin in the diet. This may be due to restrictive diets, food habits, poverty and paucity of food sources of vitamins. The secondary form is caused by smoking, use of medicines that interfere with vitamin absorption or utilization, diseases of gastrointestinal tract or excessive alcohol consumption.
Some vitamins in the B-complex group are synthesized by the intestinal bacteria. Use of antibiotics can eliminate these useful bacteria leading to low levels of vitamins. Certain components in the food can interfere with the absorption of certain vitamins.
Vitamin deficiency diseases and symptoms
Vitamin A:
Vitamin A deficiency diseases with symptoms like night blindness, growth impairment, xerosis conjunctiva, immune impairment, xerophthalmia, xerosis cornea, keratomalacia, hyperkeratosis, acne, dry hair and blindness are common in the developing countries. In the early stages it can be corrected by consuming vitamin A rich foods like eggs, liver, green leafy vegetables, yellow orange colored fruits and vegetables. One third of the children under the age of five are affected by the dearth of these nutrients.
Thiamine (vitamin B1):
Beriberi is the thiamine deficiency disease. There are two forms of beriberi namely wet beriberi and dry beriberi. Dry beriberi involved nervous system and damages peripheral nerves. Its symptoms include difficulty in walking, numbness in hands and feet, confusion, involuntary eye movements, speech difficulties and nausea. The symptoms of wet beriberi include vasodilation, peripheral edema, cardiac problems. Infantile beriberi can be fatal if not treated within 24 hours. Thiamine is found in the bran of rice. In populations, where the staple food is polished rice, as in South Asia, this disease was prevalent. Beriberi is rare in developed nations and in regions where the food habits include other cereals.
Riboflavin:
Riboflavin deficiency disease is medically known as ariboflavinosis. The symptoms include photophobia, bloodshot eyes, angular cheilitis, angular stomatitis, inflammation of the lining of mouth and tongue, mouth ulcers, iron-deficiency anemia, scrotal dermatitis, behavioural abnormalities and dry and scaling skin. It is mostly caused by its dearth in food, impaired liver function and alcoholism.
Niacin:
Pellagra is the niacin deficiency disease. It is caused by the chronic paucity of niacin in the diet. Maize (corn) is a very poor source of niacin and in populations who mainly subsist on maize, pellagra is very common. Pellagra is common in Africa, Indonesia, North Korea, and China. The typical symptoms of pellagra are three 'D's namely diarrhoea, dermatitis and depression. The symptoms include photosensitivity, edema, cardiomyopathy, psychosensory disturbances, psychomotor disturbances and emotional disturbances. Reduced intake of niacin, decreased intake of tryptophan, paucity of amino acid lysine or excessive intake of leucine can be the causes. Pellagra can be fatal if untreated.
Pantothenic acid:
Pantothenic acid is found in most of the foods and pantothenic acid deficiency is very rare. Food sources include animal products, fish, meat, rice bran, wheat bran, broccoli, cabbage, avocados, cold water fish ovaries and yeast. Pantothenic acid dearth causes impaired energy production, morning stiffness and neurological symptoms like numbness, pain severity in rheumatoid arthritis, paresthesia, and muscle cramps. The vitamin must be converted into free pantothenic acid for absorption in the intestine. The recommended dietary allowance of pantothenic acid for adults is 5 mg per day.
Pyridoxine (Vitamin B6):
Pyridoxine deficiency is very rare and it affects infants. Its symptoms include seizures, depression, dizziness, glossitis, irritability, fatigue, cheilitis, hypochromic microcytic anaemia, impaired wound healing, sleep disturbances, conjunctivitis, loss of appetite, angular stomatitis and sideroblastic anemia. It is caused by dearth of pyridoxine in the food and use of tuberculostatic medication like isoniazid. Whole grains and nuts are very good sources of this vitamin. Pyridoxine helps in the production of red blood cells. Sodium and potassium balancing in the plasma is assisted by the vitamin B6. Pyridoxine is found to reduce the formation of homocysteine and thereby maintain cardiovascular health.
Biotin:
Biotin deficiency disease is rare as its daily requirement is very low. If it is allowed to progress untreated the situation can become serious, even fatal. Vitamin B7 is available in various food sources and gut bacteria also synthesize small amounts. Raw egg white contains the protein avidin. Avidin binds to biotin and makes it unavailable for nutrition. When the egg is cooked avidin is partially denatured. Total parenteral nutrition without biotin supplementation, anticonvulsant therapy, prolonged oral antibiotic therapy, DNA mutation or pregnancy can lead to biotin paucity. Erythematous periorofacial macular rashes (red, patchy rashes near the mouth) and dermatitis are caused when biotin is not available for the body.
Folic acid deficiency diseases and symptoms:
Dearth of folic acid causes folate deficiency anemia. Such situation arises when there is dietary dearth of folate, body's need for folate increases or excessive excretion of folate by the body. Birth defects and neural tube defects in fetus occur when the mother suffers deficiency of folic acid. Tobacco smoking, malabsorption, pregnancy, lactation and excessive alcohol consumption can cause paucity of vitamin B9. The symptoms include loss of appetite, low birth weight, neural tube defects, depression, hyperhomocisteinemia, megaloblastic anemia and slow growth rate.
Cobalamins:
Vitamin B12 deficiency disease is perinicious anemia. It is a megaloblastic anemia, an anemia with larger-than-normal red blood cells. It is also known as Biermer's anemia, Addison's anemia, or Addison–Biermer anemia. In perinicious anemia, blood does not contain enough red blood cells. Inadequate cobalamins in the diet or impaired absorption due to loss of gastric parietal cells with subsequent non-secretion of intrinsic factor are the main causes of perinicious anemia. Many neurological symptoms like paresthesias, ataxia, depression, poor memory, irritability, psychosis, impaired perception of deep touch, pressure and vibration, sensory or motor deficiencies, myelin decay and developmental regression are experienced by the patients.
Vitamin C (ascorbic acid):
Ascorbic acid deficiency diseases are scurvy disease or subclinical scurvy. The symptoms of scurvy include malaise, swollen and tender joints, lethargy, breathlessness, haemorrhages in various tissues, bone and joint pain, myalgias, bleeding gum disease, loose teeth, jaundice, edema, cork-screw hair, oliguria, neuropathy, suppurating and bleeding wounds and mental instability. Citrus fruits are very rich sources of vitamin C.
Vitamin D:
Rickets in children and osteomalacia in adults are vitamin D deficiency diseases. Rickets and osteomalacia cause weak, malformed brittle bones. Rickets shows symptoms like bow legs, knock-knees, thickening of wrist and ankles, delay in eruption of milk teeth and pigeon chest. Osteomalacia in adults shows symptoms like muscular pain, fractures, skeletal pain, difficulty in climbing stairs, skeletal deformity, loss of bone mass with reduced amounts of calcium and phosphorous. Fish and fish liver oils, animal products and shrimp are rich sources. Adequate exposure to sunlight also alleviates the problem.
Vitamin E:
Vitamin E deficiency diseases are very rare and non-availability in food may never occur. However in persons with impaired absorption of fats and persons suffering from abetalipoproteinemia (genetic disease), severe diseases may be caused. Such persons may suffer from neuromuscular problems. Dysarthria, proprioception spinocerebellar ataxia and absence of deep tendon reflexes are caused due paucity of vitamin E. Some patients may suffer loss of vibratory sensation. Other symptoms include anemia, liver necrosis, retinopathy, reproduction failure, male infertility and impaired immunity. Vegetable oils and whole grains are good sources of vitamin E.
Vitamin K:
Vitamin K deficiency diseases are very rare and the non-availability in food leads to hemorrhagic conditions. Vitamin K is present in both plant and animal sources of food. Intestinal bacteria also synthesize vitamin K. The deficiency may arise in infants and elderly with poor intestinal flora, persons under prolonged broad-spectrum antibiotics and persons suffering from intestinal malabsorption. The symptoms include ecchymosis, petechiae, hematomas and massive uncontrolled bleeding at the sites of injury or surgery.
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