Fat soluble vitamin - Haemer

Question 1

What are the fat soluble vitamins?

Answer 1

A, D, E, K

Question 2

What 4 vitamins are required for energy metabolism?

Answer 2

Thiamin
Nacin
Rivoflavin
Pantothenic acid

Question 3

What two vitamins are required for hematopoiesis?

Answer 3

Folic acid

B12

Question 4

Water soluble vitamins are excreted in the ____. Fat soluble?

Answer 4

urine

Fat soluble – variable excretion. Unlike water soluble vitamins, these are stored in the body, often in fat stores.

Question 5

Water soluble vitamins are (more or less) likely to have toxic effects than fat soluble?

Answer 5

Less likely. Since water soluble vitamins aren’t stored, they are much lower toxicity, as a general rule.

Question 6

Where is Vitamin A required?

Answer 6

Retinol. Remember this molecule is key for signalling in the rods and cones. It is also required for the maintenance of the cornea and conjunctiva.

Question 7

What are two major food sources of Vitamin A?

Answer 7

Preforms retinyl palmitate–> liver, dairy, egg yolk, fish oil

Precursor Beta-carotene–>deep yellow and green vegetables (spinach, carrot, pumpkin, broccoli)

Question 8

What are the signs of Vitamin A deficiency?

Answer 8

1) Xerophthalmia (corneal dryness)
2) Bitot’s spots (sloughing of the cornea)
3) Night blindness progressing to total blindness which is irreversible
4) Immune impairment (can see measles in kids, developing countries is more common)

Question 9

What are the signs of Vitamin A overdose (note: this cannot occur from beta carotene, only from retinyl palmitate)

Answer 9

#Vomiting, increased ICP, headache
#bone pain, osteopenia/porosis
#liver damage hepatitis --> fibrosis --> failure
#death   
#birth defects e.g. isotretinoin (Accutane) Acne med, must be prescribed with birth control for girls.

Question 10

What are the functions of Vitamin D?

Answer 10

It is a hormone. 
Maintain intra/extracellular Ca++
Immune system (adaptive and innate) [tuberculosis]

Question 11

Describe the forms and metabolism of Vitamin D.

Which is measured if you ask for a Vitamin D “lab”?

Answer 11

D2–> ergocalciferol (plant)
D3–> cholecalciferol (animal)

D2 or D3 are -OHd in the liver to make 25OH Vitamin D. NOT the active form, but reflects the body’s store of vitamin D. 25OH is hydroxylated in the kidney to make the active form 1,25 OH Vitamin D.

Question 12

What is the classical symptom of Vitamin D deficiency?

Answer 12

Rickets. Occurs when plasma levels drop below ~11ng/mL,

Symptoms: failure of calcification, wide metaphyses: wrists, ‘rosary’, bone pain, bowed legs, fractures

Question 13

What drug mimics the function of the kidney in Vitamin D metabolism (creating the active form of 1,25 diHydroxy Vitamin D)?

What patients need this prescription?

Answer 13

Calcitriol

Those with significant liver or kidney disease (remember the first hydroxylation occurs in the liver).

Giving them D2 or D3 won’t do any good.

Question 14

Is vitamin D adequately transmitted in breast milk?

Answer 14

No.

Question 15

What happens in Vitamin D toxicity?

What level of VD consumption is known to be toxic?

Answer 15

#Hypercalcemia
#vomiting, seizures, nephrocalcinosis
#Sarcoidosis (granulomas activate Vitamin D)

Greater than 10,000 IU for weeks in a child
50-100,000 IU daily for three weeks or more in adults

Question 16

What is a source of Vitamin E?

Answer 16

Polyunsaturated fat rich vegetable oils (e.g. sunflower), corn, nuts, wheat germ

Question 17

What are some functions of Vitamin E?

Answer 17

antioxidant, scavenges free radicals, stabilizes cell membranes

Question 18

What is the risk of Vitamin E toxicity? What can happen with a very high dose?

Answer 18

Relatively Low
Coagulopathy
Very large doses inhibit Vit K dependent clotting factors

Question 19

What are the signs of Vitamin E deficiency?

Answer 19

Irreversible neurologic degeneration (loss of DTR, loss of coordination, loss of proprioception, spinocerebellar ataxia, neuropathy, opthalmoplegia)

Hemolytic Anemia

Question 20

What is the function of the Vitamin K?

Answer 20

Carboxylation of the clotting factor proteins 2,7,9,10.

Question 21

What is a risk of Vitamin K in a newborn?

Answer 21

Hemorrhagic disease of the newborn (2-4 month/old who is not supplemented with VK). This is horrible to witness.

**VK does not transfer across the placenta well. All newborns are given 0.5-1.0 mg IM once after birth.

Question 22

In a person treated with chronic antibiotics, what might result?

Answer 22

Vitamin K deficiency, due to killing of gut bacteria which are a main source of VK.