1. Vitamins in general. Antivitamins. Vitamin antagonists

Question 1

Vitamins in general:

Answer 1

• Vitamins are organic nutrients
• We only need a trace amount
• we get it from diet, either as a precursor or the active form
• deficiency symptoms if we lack it
• important for growth, maintainance of normal body function and reproduction
• Species need different amount (Ascorbic acid - important for man,monkey,guinea pig, but others can make it)

Question 2

Which vitamins does human require?

Answer 2

The thirteen vitamins required by human metabolism are:

vitamin A

vitamin B1 (thiamine)

vitamin B2 (riboflavin)

vitamin B3 (niacin)

vitamin B5 (pantothenic acid)

vitamin B6 (pyridoxine)

vitamin B7 (biotin)

vitamin B9 (folic acid or folate)

vitamin B12 (cobalamins)

vitamin C (ascorbic acid)

vitamin D (calciferols)

vitamin E (tocopherols and tocotrienols)

vitamin K (quinones).

Question 3

How is the structure of a vitamin?

Answer 3

Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, vitamin E consists of four tocopherols and four tocotrienols.

Question 4

Which types of antaginists are there?

Answer 4

1. structurally very similar - Antivitamin
2. antagonist with different structure

Question 5

Explain antivitamin:

Answer 5

An antivitamin is simply “a substance that makes a vitamin ineffective.” A vitamin antagonist is essentially the same thing as an antivitamin. It is a substance that lessens or negates the chemical action of a vitamin in the body.

Example: Pyrithiamine inhibits thiamine, deficiency symptoms apear, so animal need more thiamine. Dicumarol in sweet clover hay.

(none for A and D)

Question 6

What is an antagonist with different structure?

Answer 6

Avidin - Avidin is a tetrameric biotin-binding protein produced in the oviducts of birds, reptiles and amphibians and deposited in the whites of their eggs.

Since it binds to biotin it makes a unabsorbable complex and we can not take it up.

Question 7

What is thiaminase and what does it do?

Answer 7

Thiaminase is an enzyme that breaks molecules of thiamine in half, makes it useless and unable to perform the functions it is required for in the body. Even if the diet initially contained enough thiamine, the body can suffer from thiamine deficiency due to thiaminase activity.

Thiaminase is found in many species of fish and shellfish, cooking can destroy it.

Question 8

Fat-soluble vitamins

Answer 8

Fat-soluble vitamins are stored in the fatty tissues of the body and the liver. Vitamins A, D, E, and K are fat-soluble. These are easier to store than water-soluble vitamins, and they can stay in the body as reserves for days, and sometimes months.

Fat-soluble vitamins are absorbed through the intestinal tract with the help of fats, or lipids.

Question 9

Water-soluble vitamins

Answer 9

Water-soluble vitamins do not stay in the body for long. The body cannot store them, and they are soon excreted in urine. Because of this, water-soluble vitamins need to be replaced more often than fat-soluble ones.

Vitamin C and all the B vitamins are water soluble.

Question 10

Explain vitamin A:

Name:
Deficiency:
Good source:

Answer 10

Chemical names: Retinol, retinal, and four carotenoids, including beta carotene.

It is fat soluble.

Deficiency may cause night-blindness and keratomalacia, an eye disorder that results in a dry cornea.

Good sources include: Liver, cod liver oil, carrots, broccoli, sweet potato, butter, kale, spinach, pumpkin, collard greens, some cheeses, egg, apricot, cantaloupe melon, and milk.

Question 11

Vit B1

Name:
Deficiency:
​Good source:

Answer 11

Chemical name: thiamine.

It is water soluble.

Deficiency may cause beriberi and Wernicke-Korsakoff syndrome.

Good sources include: yeast, pork, cereal grains, sunflower seeds, brown rice, whole-grain rye, asparagus, kale, cauliflower, potatoes, oranges, liver, and eggs.

Question 12

Vit B2

Name:
Deficiency:
​Good source:

Answer 12

Vitamin B2

Chemical name: Riboflavin

It is water soluble

Deficiency may cause ariboflavinosis

Good sources include: asparagus, bananas, persimmons, okra, chard, cottage cheese, milk, yogurt, meat, eggs, fish, and green beans

Question 13

Vit B3

Name:
Deficiency:
​Good source:

Answer 13

Vitamin B3

Chemical names: Niacin, niacinamide

It is water soluble.

Deficiency may cause pellagra, with symptoms of diarrhea, dermatitis, and mental disturbance.

Good sources include: liver, heart, kidney, chicken, beef, fish (tuna, salmon), milk, eggs, avocados, dates, tomatoes, leafy vegetables, broccoli, carrots, sweet potatoes, asparagus, nuts, whole-grains, legumes, mushrooms, and brewer’s yeast.

Question 14

Vit B5

Name:
Deficiency:
​Good source:

Answer 14

Vitamin B5

Chemical name: Pantothenic acid

It is water soluble.

Deficiency may cause paresthesia, or “pins and needles.”

Good sources include: meats, whole-grains (milling may remove it), broccoli, avocados, royal jelly, and fish ovaries.

Question 15

Vit B6

Name:
Deficiency:
​Good source:

Answer 15

Vitamin B6

Chemical names: Pyridoxine, pyridoxamine, pyridoxal

It is water soluble.

Deficiency may cause anemia, peripheral neuropathy, or damage to parts of the nervous system other than the brain and spinal cord.

Good sources include: meats, bananas, whole-grains, vegetables, and nuts. When milk is dried, it loses about half of its B6. Freezing and canning can also reduce content.

Question 16

Vit B7

Name:
Deficiency:
​Good source:

Answer 16

Vitamin B7

Chemical name: Biotin

it is water soluble.

Deficiency may cause dermatitis or enteritis, or inflammation of the intestine.

Good sources include: egg yolk, liver, some vegetables.

Question 17

Vit B9

Name:
Deficiency:
​Good source:

Answer 17

Vitamin B9

Chemical names: Folic acid, folinic acid

It is water soluble.

Deficiency during pregnancy is linked to birth defects. Pregnant women are encouraged to supplement folic acid for the entire year before becoming pregnant.

Good sources include: leafy vegetables, legumes, liver, baker’s yeast, some fortified grain products, and sunflower seeds. Several fruits have moderate amounts, as does beer.

Question 18

Vit B12

Name:
Deficiency:
​Good source:

Answer 18

Vitamin B12

Chemical names: Cyanocobalamin, hydroxocobalamin, methylcobalamin

It is water soluble.

Deficiency may cause megaloblastic anemia, a condition where bone marrow produces unusually large, abnormal, immature red blood cells.

Good sources include: fish, shellfish, meat, poultry, eggs, milk and dairy products, some fortified cereals and soy products, as well as fortified nutritional yeast.

Vegans are advised to take B12 supplements.

Question 19

Vit C

Name:
Deficiency:
​Good source:

Answer 19

Vitamin C

Chemical name: Ascorbic acid

It is water soluble.

Deficiency may cause megaloblastic anemia.

Good sources include: fruit and vegetables. The Kakadu plum and the camu camu fruit have the highest vitamin C contents of all foods. Liver also has high levels. Cooking destroys vitamin C.

Question 20

Vit D

Name:
Deficiency:
​Good source:

Answer 20

Vitamin D

Chemical names: Ergocalciferol, cholecalciferol.

It is fat soluble.

Deficiency may cause rickets and osteomalacia, or softening of the bones.

Good sources: Exposure to ultraviolet B (UVB) through sunlight or other sources causes vitamin D to be produced in the skin. Also found in fatty fish, eggs, beef liver, and mushrooms.

Question 21

Vit E

Name:
Deficiency:
​Good source:

Answer 21

Vitamin E

Chemical names: Tocopherols, tocotrienols

It is fat soluble.

Deficiency is uncommon, but it may cause hemolytic anemia in newborns. This is a condition where blood cells are destroyed and removed from the blood too early.

Good sources include: Kiwi fruit, almonds, avocado, eggs, milk, nuts, leafy green vegetables, unheated vegetable oils, wheat germ, and whole-grains.

Question 22

Vit K

Name:
Deficiency:
​Good source:

Answer 22

Vitamin K

Chemical names: Phylloquinone, menaquinones

It is fat soluble.

Deficiency may cause bleeding diathesis, an unusual susceptibility to bleeding.

Good sources include: leafy green vegetables, avocado, kiwi fruit. Parsley contains a lot of vitamin K.