MATCH THE MICRONUTRIENT TO THE STATEMENTS BELOW: Thiamin Vitamin B 12 Iron Magne
ID: 127617 • Letter: M
Question
MATCH THE MICRONUTRIENT TO THE STATEMENTS BELOW:
Thiamin Vitamin B 12 Iron Magnesium
Vitamin C Zinc Niacin Vitamin A
Vitamin D Vitamin E Folate Calcium
Vitamin B 6 Vitamin K Iodine Selenium
Directions: Type in the micronutrient from the list above that best matches each of the following statements below. Type your answer to the right of each statement or number them to match. Only use micronutrients from the list above. You may use a micronutrient more than once, or not at all. Hint: Read each statement carefully!
Please choose only one answer per question/statement.
19. A deficiency of this vitamin has resulted in high rates of night-blindness
in developing countries
20. Newborns do not have the intestinal bacteria required to produce this vitamin
Explanation / Answer
19)
People with night blindness often have difficulty driving at night or seeing long distances in low light. The most common cause of night blindness is a vitamin A deficiency, but other disorders can cause the condition. Cataracts, birth defects, certain medications and a disease called retinitis pigmentosa, which causes retinal damage, can all cause night blindness, according to the National Institutes of Health. Symptoms of night blindness include loss of side or peripheral vision, loss of central vision, and decreased vision at night.
Vitamin A occurs in the retina of the eye and is required in the process of vision to adjust to light of varying intensity (dark adaptation). It occurs in the light receptor cells in the retina in combination with protein. This substance is known as visual purple(rhodopsin). It is bleached in the presence of light, which enables a person to see. Some vitamin A is used up in he process. If more vitamin A is not avaible, ability to adjust to changes in intensity of light is impaired. Night blindness occurs in severe vitamin A deficiency; it indicates the inability of a person to see at night, when the amount of light is far too little to permit adequate vision.
Epithelial tissues cover the outer surface of the body, line the major cavities and all the tubular systems in the body. These are specialised tissues of which the outer covering is resistant; protective epidermis and the internal tissue is a secretory mucous membrane. Inadequate supplies of vitamin A results in suppression of the normal secretions and produces a keratinised(dry, horny) type of epithelium. The skin may become excessively dry and mucous membrane may fail to secrete normally and hence be prone to bacterail invasion.
In vitamin A deficiency keratin producing cells replace mucus secreting cells in many epithelial tissues of the body. This is the basis of the pathological process termed xerosis that leads to the drying of the conjunctiva and cornea of the eye. The process can be revered by vitamin A. It has become clear recently that vitamin A mainly in the form of retinoic acid plays a key hormone-like role in cell differentiation throughtout the tissue of the body. Hence the formation of retinoic acid must be regulated precisely.
20)
Vitamin K is needed by humans for blood clotting. Older children and adults get most of their vitamin K from bacteria in the gut, and some from their diet. Without enough vitamin K, small cuts can go on bleeding for a very long time and big bruises can happen from small injuries. Bleeding can also occur in other parts of the body, such as the brain (causing one type of stroke).
Babies have very little vitamin K in their bodies at birth. Vitamin K does not cross the placenta to the developing baby, and the gut does not have any bacteria to make vitamin K before birth. After birth, there is little vitamin K in breast milk and breastfed babies can be low in vitamin K for several weeks until the normal gut bacteria start making it. Infant formula has added vitamin K, but even formula-fed babies have very low levels of vitamin K for several days.
With low levels of vitamin K, some babies can have very severe bleeding - sometimes into the brain, causing significant brain damage. This bleeding is called haemorrhagic disease of the newborn (HDN)
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