Vitamins and Nutrition

Vitamin A is important for good vision.

Vitamins are essential organic compounds that the body requires in small amounts for normal metabolic functioning, enzyme activity, and tissue maintenance. Unlike macronutrients (carbohydrates, proteins, fats), vitamins don't provide energy directly but are crucial cofactors in metabolic reactions. They are not primarily energy sources or fiber providers.

Vitamin D is synthesized in the skin when 7-dehydrocholesterol is exposed to UV-B radiation from sunlight, earning it the name 'sunshine vitamin.' This process converts the cholesterol derivative into previtamin D3, which then becomes active vitamin D. Vitamins A, B, and C must be obtained from dietary sources as the human body cannot synthesize them.

The chemical name of vitamin C is ascorbic acid, a water-soluble antioxidant essential for collagen synthesis, wound healing, and immune function. Thiamine is vitamin B1, riboflavin is vitamin B2, and glutamic acid is an amino acid involved in neurotransmission, not a vitamin.

Vitamin A is fat-soluble, meaning it dissolves in lipids and can be stored in body fat and the liver. Water-soluble vitamins (C and B-complex including riboflavin) dissolve in water, are not stored significantly, and excess is excreted in urine. This distinction is important for both absorption and toxicity considerations.

Vitamin B is a water soluble vitamin. Hence, it is odd one among the options.

Scurvy is caused due to deficiency of vitamin C.

Vitamin K is necessary for the synthesis of prothrombin in the liver for normal clotting of blood. 

Vitamin C is a water soluble vitamin and is present in the largest amount in the body in the adrenal cortex. It is essential for healthy gums, bones  teeth, and formation of erythrocytes and antibodies.

Vitamin D is also known as calciferol. It is required for the normal absorption and deposition of calcium and phosphate. 

Vitamin E or Tocopherol is an excellent anti oxidant. It helps to keep the skin healthy and decreases the fragility of erythrocytes. 

Citrus fruits, oranges, etc. are rich sources of vitamin C. So, the patient suffering from its deficiency should be advised to take the citrus fruits.

Vitamin C is essential for healthy gums, bones and teeth and formation of erythrocytes and antibodies. It helps to maintain the walls of the blood capillaries. 

Fortification is the process by which manufacturers add micronutrients such as vitamins and minerals to food. Fortified milk is milk that is enriched with vitamins. Most fortified milk contains vitamins A and D.

These do not help in blood clotting.