ANC-1 Explain The Role of Vitamin A and Vitamin D in our body. List Some Food Sources

ANC-1 Explain The Role of Vitamin A and Vitamin D in our body. List Some Food Sources

IGNOU ANC-1 Solved Assignment 2018-2019 

Application Oriented Course in Nutrition for the Community

Assignment Code: ANC-1/AST-1/TMA-1/2018-19

ANC-1 Solved Assignment Question 3

a) Explain the role of vitamin A and vitamin D in our body. List some food sources. (2)

Answer:

The role of vitamin A in our body

Maintaining normal vision: Vitamin A plays an important role in maintaining normal vision. The retina has two kinds of cells - rods and cones. The rods contain a pigment called rhodopsin which helps us to see in dim light. Rhodopsin is formed by the combination of a specific form of vitamin A with a protein.

Supporting growth: Vitamin A is essential for the growth of the skeleton and soft tissues. The exact role of the vitamin in the growth of the body is still not understood. Research studies in this area have indicated that with the deficiency of vitamin A in the body, bones do not grow to their full length and the overall growth of the body is affected.

Protecting against disease: Vitamin A plays an important role in keeping epithelial tissues moist and healthy. Some examples of epithelial tissues are the skin, the lining of our eyes and the lining of organs like the intestine and lungs. Without vitamin A the epithelial tissue will become dry and cracks will appear in the skin or inner walls of the digestive tract or lungs.

Some food sources

Vitamin A or retinol is found only in the foods of animal origin. Animal foods like milk, butter, ghee, egg, fish and liver are rich sources of vitamin A. Liver oils of fish like halibut, cod, and shark are the richest sources. Plant foods do not contain retinol. They contain carotenoids which can be converted to vitamin A in the body. Beta-carotene is the most widely distributed carotenoid in plant foods. Green leafy vegetables, yellow and orange vegetables like carrot and pumpkin and fruits like mango, papaya are rich sources of beta-carotene.

The role of vitamin D in our body

Vitamin D makes bones strong and healthy. Minerals like calcium and phosphorus, when deposited in the bones, make them strong and hard. The process of deposition of minerals in the bones is termed as mineralization of bones. Vitamin D aids the process of mineralization in two ways:

i)            by increasing the absorption of calcium and phosphorus and

ii)           by helping in the deposition of calcium and phosphorus in bones.

Some food sources

The easiest way of obtaining vitamin D is enough exposure to sunlight. Foods of animal origin like eggs, liver and butter contain vitamin D in significant amounts. It is, however, the fish liver oils which are the richest sources.