. Adventures with animals and plants. Biology. PROBLEM I. How to Choosc Foods Wisely 179. Fig. 197 This rat was fed a diet lackmg vitamin B.,. During six weeks of a diet rich in vitamiji B.,, its weight increased from 6^ grains to 16^ grams. Why should several rats be used in such an experime^it? Explain, (u. s. department of agriculture) deficiency causes drying up of the tear glands and damage to the eyes. And in- sufficient amounts of vitamin A in the body result in the inability of the eyes to produce a substance called visual pur- ple; this is needed for vision in dim light. Furthermore v
. Adventures with animals and plants. Biology. PROBLEM I. How to Choosc Foods Wisely 179. Fig. 197 This rat was fed a diet lackmg vitamin B.,. During six weeks of a diet rich in vitamiji B.,, its weight increased from 6^ grains to 16^ grams. Why should several rats be used in such an experime^it? Explain, (u. s. department of agriculture) deficiency causes drying up of the tear glands and damage to the eyes. And in- sufficient amounts of vitamin A in the body result in the inability of the eyes to produce a substance called visual pur- ple; this is needed for vision in dim light. Furthermore vitamin A keeps the mu- cous membranes of the body normal and healthy. The vitamin B complex. What was formerly called vitamin B is really a group of vitamins. The one in the group asso- ciated with beriberi is now called vitamin Bi or thiamin. People getting an insuf- ficient amount of thiamin are easily fa- tigued and have a poor appetite; this may be followed by loss of weight, irrita- bility, and mental depression, A defi- ciency of thiamin in the diet is common. The best concentrated sources of thia- min are liver, wheat germ, and yeast. It occurs quite abundantly in wheat, rice, barley, peanuts, dried beans, peas, and soybeans. Unfortunately, the grains are often refined before they are used. In the refining process the vitamins, which are in the covering of the seed and in the germ, are removed. Niacin (formerly called nicotinic acid) is another vitamin of this group. Defi- ciency of niacin causes the disease known as pellagra. In the United States alone about 100,000 people suffer from this disease. There have often been outbreaks of pellagra in institutions where too strict economy was practised and no fresh vegetables, milk, or fruits were included in the diet. A less marked deficiency causes loss of appetite and a general breakdown of morale. As in the case of thiamin its best source is liver and yeast. Other good sources are kidneys, sweet- breads, milk, and cheese,
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Keywords: ., bookcentury1900, bookpublisherbostondcheath, booksubjectbiology
