Summary:
This unit discusses vitamins, which are essential organic compounds required in small amounts for various bodily functions. Vitamins are classified into two groups: fat-soluble and water-soluble. Fat-soluble vitamins include A, D, E, and K, which are stored in the body and absorbed with fats.
- Vitamin A: Found in animal foods as retinol and in plant foods as carotenoids, which convert to retinol in the body. Functions include maintaining normal vision, supporting growth, and protecting against diseases by keeping epithelial tissues healthy.
- Vitamin D: Known as the “sunshine vitamin” because it’s synthesized in the skin upon sunlight exposure. It’s also found in animal foods and aids in bone health by increasing calcium and phosphorus absorption and deposition in bones.
Check Your Progress Exercise 1:
1) Carotenoids are pigments found in plant foods that can be converted into vitamin A in the body. Rich sources of beta carotene include ripe fruits such as mango and papaya, yellow/orange vegetables like carrot and pumpkin, and green leafy vegetables such as spinach, mustard leaves, and fenugreek leaves.
2)
a) False. Bile is essential for the effective absorption of fat-soluble vitamins like vitamin A and D. (Correction: True)
b) False. We primarily obtain vitamin D from sunlight exposure, although it is also found in some dietary sources. (Correction: False)
c) False. Vitamin A helps keep epithelial tissues moist and healthy, preventing dryness. (Correction: False)
d) True.
e) True.
Summary:
Vitamin E is found in various foodstuffs, with vegetable oils being rich sources along with whole grain cereals, dark green leafy vegetables, nuts, and seeds. It primarily functions to protect other substances like fatty acids and vitamins A and C from destruction in the body and in foods.
Vitamin K is abundant in green leafy vegetables, animal foods like egg yolk and liver, and is also synthesized by helpful bacteria in the small intestine. Its main function is aiding in blood clotting by facilitating the formation of prothrombin, a crucial protein in the clotting process.
Note:
Vitamins E and K play vital roles in maintaining bodily functions, particularly in protecting against oxidative damage (vitamin E) and ensuring proper blood clotting (vitamin K). Incorporating a variety of foods rich in these vitamins is important for overall health and well-being.
Check Your Progress Exercise 2:
1) Match the following:
a) Vitamin A – ii) Vision in dim light
b) Vitamin D – iv) Absorption of calcium and phosphorus
c) Vitamin E – i) Prevention of destruction of unsaturated fatty acids
d) Vitamin K – iii) Clotting of blood
2) Fill in the blanks:
i) Fish liver oils are the richest sources of vitamins A and D.
ii) Rods of the retina are sensitive to dim light.
iii) Presence of bile and pancreatic enzymes aids in the absorption of fat-soluble vitamins.
iv) Vitamin K is also known as the clotting vitamin.
Summary:
Water-soluble vitamins, including vitamin C and the B-complex group, cannot be stored in the body in significant amounts and are excreted in urine when consumed in excess. The B-complex group includes thiamine (B1), riboflavin (B2), folic acid, niacin, and vitamin B12, which are essential for the metabolism of carbohydrates, proteins, and fats.
- Thiamine (B1): Found in both animal and plant foods, thiamine plays a crucial role in carbohydrate metabolism, helping the body utilize glucose for energy.
- Riboflavin (B2): Widely distributed in plant and animal foods, riboflavin aids in carbohydrate, fat, and protein metabolism by forming part of coenzymes that release energy from these nutrients.
- Niacin: Found in meat, fish, poultry, cereals, pulses, nuts, and oilseeds, niacin can also be synthesized in the body from tryptophan. It helps release energy from carbohydrates, fats, and proteins.
- Folic Acid: Abundant in green leafy vegetables and organ meats, folic acid is essential for blood formation, particularly in the development of red blood cells.
- Vitamin B12 (Cobalamin): Found only in animal foods, vitamin B12 is crucial for the proper functioning of the digestive tract, nervous system, and bone marrow. It is also synthesized in the intestinal tract by certain bacteria.
Note:
Water-soluble vitamins are vital for various metabolic processes in the body, and a balanced diet rich in fruits, vegetables, whole grains, and animal products is essential for meeting the body’s requirements. Processing of foods can affect the content of these vitamins, emphasizing the importance of diverse dietary choices and awareness of food processing methods for optimal nutrition.
Check Your Progress Exercise 3:
1) Sprouting and fermentation can increase the content of B vitamins in food. During sprouting, certain enzymes are activated, leading to biochemical changes that increase the availability of B vitamins. Similarly, fermentation involves the action of beneficial microorganisms that produce B vitamins as byproducts, thereby enhancing their content in fermented foods.
2) Thiamine (B1), riboflavin (B2), niacin, folic acid, and vitamin B12 (cobalamin) play significant roles in blood formation.
Summary:
Vitamin C, also known as ascorbic acid, is primarily found in fresh fruits and vegetables, earning it the nickname “fresh food vitamin.” Citrus fruits like oranges, lemons, and limes, as well as other fruits and vegetables such as guava, amla, papaya, green leafy vegetables, tomatoes, green chillies, and capsicum, are excellent sources of vitamin C. While root vegetables like potatoes and sweet potatoes contain small amounts, they contribute significantly only when consumed in large quantities. Cereals and pulses are generally poor sources of vitamin C, but they become good sources when sprouted and fermented. Animal foods such as fish, meat, milk, poultry, and eggs contain little to no ascorbic acid.
Vitamin C plays several important roles in the body:
1) Healing wounds and maintaining firmness of blood vessels.
2) Assisting in overcoming conditions of injury, infection, and other stresses.
3) Aiding in the absorption of iron.
4) Protecting certain substances from breakdown in the body, such as vitamin A and some fatty acids.
Note:
Vitamin C is crucial for various bodily functions, including wound healing, immune function, and iron absorption. Consuming a diet rich in fruits and vegetables is essential for meeting the body’s vitamin C requirements and supporting overall health and well-being.
Check Your Progress Exercise 1:
1) Give reasons for the following:
i) Refined flours like maida and suji have less thiamine as compared to atta or whole wheat flour.
Reason: During the refining process, the outer layers of the grain, which contain higher concentrations of thiamine and other nutrients, are removed. Therefore, refined flours like maida and suji have lower thiamine content compared to atta or whole wheat flour.
ii) Milk can help to meet niacin needs.
Reason: Milk contains tryptophan, an amino acid that can be converted into niacin in the body. Therefore, consuming milk can contribute to meeting niacin needs indirectly through the conversion of tryptophan into niacin.
iii) Ascorbic acid is termed the “fresh food vitamin”.
Reason: Ascorbic acid, or vitamin C, is primarily found in fresh fruits and vegetables. These fresh foods are rich sources of vitamin C, and consuming them helps maintain optimal levels of vitamin C in the body. Hence, vitamin C is often referred to as the “fresh food vitamin” due to its association with fresh produce.