Water soluble vitamins lecture

Question 1

Biochemically, vitamins function as

Answer 1

Cofactors (co-enzymes) for enzymatic reactions

Question 2

What are the carrier proteins for Adek

Answer 2

A- retinol binding protein
D- vitamin d binding protein
E-alpha tocopherol transfer protein
I-ApoE

Question 3

Vitamin A is present in animals as … and plants as …

Answer 3

Preformed vitamin A

Provitamins A(beta carotene)

Question 4

Active forms of vitamin A are

Answer 4

Retinol
Retinal(retinaldehyde)
Retinoic acid
B-carotene

Question 5

Primary sources of vitamin A

Answer 5

Animal products: liver, egg yolk, dairy products (retinol)

Plant products: orange and red colored fruits and vegetables, green leafy vegetables(beta carotene)

Question 6

Major functions of vitamin A

Answer 6

Differentiation
Growth
Reproduction
Vision

Also helps In functioning of zinc finger proteins

Question 7

deficiency manifestations of vitamin A

Answer 7

Night blindness
Xerophthalmia(conjunctival and corneal xerosis)
Keratomalacia(when xerophthalmia persists for a long time)-softening of the cornea
Bitot’s spots(grayish white triangular plaques formed on conjunctiva)
Hyper keratosis

Question 8

Normal serum levels of retinol binding protein

Answer 8

40 to 60 microgram/ml

Question 9

Vitamin A levels in blood are a red flag when lower than…

Answer 9

25 milligram per deciliter

Question 10

Sources of vitamin D

Answer 10

Sunlight, eggs, cheese, salmon, yoghurt

Question 11

What are the forms of vitamin d

Answer 11

D2(ergocalciferol) derived from plants and other food sources
D3(cholecalciferol)synthesized by body when exposed to sunlight. Precursor is 7-dehydrocholestrol
Calcidiol(25(OH)D
Calcitriol(1,25(OH)2D most active

Question 12

Main roles of vitamin D

Answer 12

Regulation of calcium and phosphorus levels

Promotes bone formation and mineralization

Question 13

Normal 25 dihydroxyvitaminD levels in blood?

Answer 13

20 to 40 ng/mL

Question 14

How to treat vitamin D deficiency?

Answer 14

Oral ergo calciferol at 50000 IU per week for 8 weeks

After, maintenance levels of cholecalciferol at 800 to 1000 IU per day from dietary and supplemental sources

Question 15

Active form of vitamin E known as

Answer 15

Tocopherol

Question 16

Main function of vitamin E

Answer 16

Very potent antioxidant

Quenches the lipid peroxidation chain and protects the plasma membrane from the attack of free radicals

Question 17

Deficiency of vitamin E

Answer 17

No major disease states due to adequate levels in average diet

Question 18

Sources of vitamin E

Answer 18

Trout
Red bell pepper
Avocado
Sunflower oil
Almonds

Question 19

Vitamin E deficiency is seen in which persons?

Answer 19

People who
Cannot absorb dietary fat
Premature infants
Mutations in gene for tocopherol transfer protein

Deficiency causes neurological problems due to poor nerve conduction, and anaemia due to oxidative damage of RBCs

Question 20

Detection of vitamin D deficiency

Answer 20

Alpha tocopherol test
Normal level usually with the range of 5.5-17 milligrams per liter

Treatment is giving high doses of vitamin E

Question 21

Vitamin K some sources?

Answer 21

Broccoli
Squash
Parsley
Tomatoes
Swiss chard
Kale
Olive oil

Question 22

2 types of vitamin K. They are

Answer 22

Phylloquinone(K1) and menaquinone(K2)

Question 23

Main function of vitamin K(1)

Answer 23

Blood coagulation

Aids in gamma carboxylation of coagulation factors. Ie converting inactive prothrombin to thrombin(factor II)

Question 24

Function of vitamin k2

Answer 24

Bone mineralization and prevents vascular calcification

Question 25

Clinical manifestations of vitamin k deficiency

Answer 25

Bruising tendency
Mucous membrane hemorrhage
Post traumatic bleeding
Internal bleeding

Question 26

Warfarin and dicoumarol act as anticoagulants how?

Answer 26

Competitive inhibition of gamma carboxylation system due to structural similarity with vitamin K

Question 27

How is vitamin D deficiency discovered physically

Answer 27

Excessive bleeding occurring

Question 28

What lab test is done to determine vitamin k deficiency

Answer 28

Prothrombin time test

Performed by adding calcium and thromboblastin(an activator of the extrinsic pathway) to the blood sample and measuring the time required for fibrin blood clot formation

Question 29

Average blood clot time range?

Answer 29

10 to 13 seconds

Question 30

Treatment for vitamin K synthesis is by which drug

Answer 30

Phytonadione (k1)

Catalyzes hepatic synthesis of blood clotting factors. Factor II(active prothrombin) factor VII factor IX factor X