Question

1.) Discuss the roles of the B vitamins in energy metabolism. Why might vegans develop a vitamin B12 deficiency?

2.)Describe the differences between fat-soluble vitamins and water-soluble vitamins. Explain how vitamin D differs from all other vitamins in both dietary requirements and functions in the body.

3.)Define bioavailability of vitamins. List four factors that affect bioavailability of vitamins and give examples for each.

4.)Consider the following hypothetical discussion you are having with a friend. She tells you that you should be taking antioxidants as a supplement to your diet. You ask her why you should take antioxidants. She replies that antioxidants defend against cancer and protect against free radicals in your body, which damage tissues, and interfere with healthy metabolism. What is your reply? In that reply, demonstrate an understanding of the positive and negative effects of free radicals in the body and why you should, or should not, take antioxidant supplements.

Answer 1

1)Role of vitamin B in energy metabolism ​​​​​​

• Helps in glucose metabolism. Breakdown glucose for energy production
• Helps in synthesis of ribose from glucose and required for the synthesis of RNA, DNA and ATP

Vegans develop vitamin B12 deficiency because, aside from fortified breakfast cereal the only reliable source of vitamin B12 are animal products (liver, egg, fish and milk are the source of vitamin B12)

2)difference between water and fat soluble vitamins ​​​​​​

Vitamins	Absorption	Transportation	Storage	Excretion	Requirements
Water soluble vitamins	easily absorbed, directly to the blood	travel easily	water filled part in the body	kidney	frequent doses needed
Fat soluble vitamins	first in lymph then blood	required protein carriers	cells associated with fat	less excreted tend to remain storage	periodic doses

• Vitamin D is different from other vitamins. Body can make vitamin D in the presence of sunlight . But body body cannot make other vitamins .
• When body gets vitamin D, it then turns vitamin D in to a hormone called Calcitriol
• Vitamin D synthesis does not depend on food we consume

3)Bioavailabilt of vitamins

Bioavailability of vitamins is how nutrients are absorbed by the body. Bioavailability of vitamins is the proportion of nutrients that is absorbed from the diet and used for the body function

Factors affecting :

• Physiological factors : example - anabolic demands (growth in infancy and childhood pregnancy and lactation)
• Diet related factors :example - food structure (easy structure of food helps to absorb nutrients easily)
• Chemical form: example - it's solubility the lumen
• Competition for transport protein or absorption sites :example - between metals

4) Antioxidants can fight free radicals damage. Antioxidants are good for healthy living and anti aging

Oxygen we breathe enter in the lungs they get metabolized in the blood and create unstable molecule called free radicals. Which can cause damage to the DNA and cell membranes. Some radicals need to body function but excess may cause diseases such as cancer, cardiovascular disease, lung and liver disease

Antioxidants minimize the cell damage from oxidants and helps to fight against aging and cancer. The consumption of antioxidant supplements, which can actually prevent the products of natural antioxidant body makes. Supplements cannot balance the loss of own antioxidants which are produced naturally rather than artificially.