Vitamin Deficiency

Question 1

Vitamin A

Function?

Answer 1

essential for normal differentiation of epithelial cells into specialized tissue, prevents squamous metaplasia.

Question 2

What is Vitamin A used to treat?

Answer 2

APL

Measles

Acne (oral isotretinoin)

Question 3

Deficiency in Vit A lead to what?

Answer 3

Night blindness - Nyctalopia

Dry skin

Corneal squamous metaplasia - bitot spots

Question 4

Vitamin A Effects in the following?

• Toxicity
• Pregnancy

Answer 4

• N/V vertigo, blurred vision (acute)
• alopecia, dry skin, hepatic toxicity (chronic)
• Cleft palate, cardiac abnormalities (pregnant)

Note: the pregnancy related issues is why a negative pregnancy test and TWO forms of contraception are required before starting isotretinoin

Question 5

Vit. B1 - Thiamine

• Enzymes that need B1

Answer 5

• Branched chain ketoacid dehydrogenase
• alpha-ketoglutarate dehydrogenase (TCA cycle)
• Pyruvate dehydrogenase (links glycoslysis to TCA)
• Transketolase (HMP shunt)

Question 6

Deficiency in B1 - Thiamine

• what happens when glucose is administered?
• What do we administer before glucose (dextrose)?

Answer 6

Note: Impaired glucose breakdown worsened by infused glucose (dextrose)

• highly aerobic tissue effect first i.e. brain and heart
• Give thiamine before glucose (dextrose)

Question 7

How do we diagnose a Thiamine Deficiency (B1)?

Answer 7

Made by increase RBC transketolase activity following B1 (thiamine) administration

Question 8

What is wernicke encephalopathy?

Answer 8

acute life threatening neurologic condition with a classic triad:

confusion, opthalmoplegia (paralysis of eye muscle and those surrounding the eye), ataxia

Question 9

What is Korsakoff Syndrome?

Answer 9

amnestic disorder due to chronic alcohol consumption, presents with confabulation, personality changes, and memory loss (permanent)

Question 10

What is Wernicke Korsakoff Syndrome?

Answer 10

damage to medial dorsal nucleus of the thalamus, mammillary bodies. presentation is combination of wernicke and korsakoff

Question 11

What is Dry BeriBeri?

What is Wet BeriBeri?

Answer 11

Dry - polyneuropathy, symmetric muscle wasting

Wet - HOCF (dilated cardiomyopathy), edema

Question 12

Vit. B2 (riboflavin)

Function ?

Answer 12

Component of flavins FAD and FMN, used as cofactors in redox reactions, eg, the succinate dehydrogenase reaction in the TCA cycle

Question 13

Vit B2

Deficiency ?

Answer 13

Cheilosis (inflammation of lips, scaling and fissures at the corners of the mouth), Corneal vascularization

Question 14

Vit B3 - Niacin - Nicotinic Acid

Function?

Answer 14

Consituent of NAD+, NADP (used in redox reactions).

Derived from tryptophan. synthesis requires Vit B2 and B6. Used to treat dyslipidemia, lowers levels of VLDL and raises HDL

Question 15

Deficiency From B3 - Niacin - Nicotinic acid

Answer 15

Glossitis.

Pellagra - deficient: Diarrhea, Dementia, Dermatitis

3 Ds of Pellagra

Question 16

Vit B3 Excess - Niacin - Nicotinic acid

Answer 16

Facial flushin (induced by prostaglandins not histamine can avoid by taking aspirin with niacin), hyperglycemia, hyperuricemia - podagra

Question 17

What is Hartnups Disease?

Tx?

Answer 17

AR - deficiency of nuetral amino acid (tryptophan) transports in renal tubular cells on enterocytes. neutral amino aciduria and decreased absorption from gut leading to decreased tryptophan for conversion to niacin (B3)

- Lead to pellagra like symptoms

Tx: high protein diet and Niacin

Question 18

Vitamin B5 - pentothenic acid - “pento” = 5

• Function?

Answer 18

Needed for Coenzyme A (CoA, a cofactor for acyl transfers) and fatty acid synthase.

Question 19

Vitamin B6 - pyrido(si)xine

Function ?

Deficiency leads to what ?

Answer 19

• converted to PLP which is needed for AST/ALT
• Needed for a bunch of neurotransmitters
• deficiency - sideroblastic anemia