L12: Vitamins, Minerals and Alcohol Metabolism

Question 1

Water Soluable Vitamains?

Answer 1

B Complex (8)
Vitamin C

Question 2

Fat Soluable Vitamins

Answer 2

A
D
E
K

Question 3

Vitamins that Function as Co-Enzymes/ Co-Factors?

Answer 3

Vit A (Rhodopsin-Rod Cells)
Vit B Complex (8)
Vit K (Blood Clotting)

Question 4

Vitamins that Function as Antioxidants?

Answer 4

Vit A
Vit C
Vit E

Question 5

Vitamins that have Hormonal Functions?

Answer 5

Vit A (Epithelial Maintenance)
Vit D (Ca++ metabolism)

Question 6

Functions of B-Complex Vitamins?

Answer 6

• Energy metabolism – generation of ATP from glucose and fats
• Amino acid metabolism
• Nucleotide synthesis

Question 7

Enzymes that require Vitamin B1

Resulting Deficiency?

Answer 7

These Enzymes require Thiamin (B1)

• Pyruvate Dehydrogenase
• a-Ketogluterate Dehydrogenase

Deficiency results in Beriberi: Muscle wasting disease

Question 8

What causes Beriberi?

Answer 8

B1 Thiamin deficiency

Question 9

What is Vitamin B2 (Riboflavin) a precursor for?

Answer 9

NAD

Question 10

What is Vitamin B3 a precursor for?

Resulting Deficiency?

Answer 10

B3 (Niacin) is a Pre-cursor of NAD

Pellagra: Sour Skin Dermatitis on hands and shoulder (Casal’s Collar)

Question 11

What causes Pellagra?

Answer 11

B3 (Niacin) deficiency

Question 12

Constituent of Co-A (Part of Acyetly Co-A)?

Answer 12

B5 (Pantothenic acid)

Question 13

Co-enzyme in carboxylation/FA synthesis?

Answer 13

B7 (Biotin)

Question 14

Role of Vitamin B9?

Resulting Deficiency?

Answer 14

Folic acid- B9 is essential for Neural tube formation

Spina Bifida: Neural tube deficiency

Question 15

Co-enzyme key in Erythropoiesis?

Answer 15

B12 (Cobalamin)

Question 15

What causes Spina Bifida?

Answer 15

Deficiency of Vitamin B9 (Folic Acid) causes impaired DNA replication in dividing cells => neural tube defects

Question 16

What causes Pernicious Anemia?

Answer 16

Low red blood cell production resulting from lack/loss of intrinsic factor needed for the absorption of vitamin B12-Cobalmin. Intrinsic Factor deficiency caused by autoimmune disease targeting parietal cells of the stomach/ intrinsic factor)

Question 17

Vitamin that is an essential cofactor in Amino Acid Metabolism?

Consequences of Deficiency?

Answer 17

Pyridoxal (B6) Phosphate is responsible for:

• All transamination reactions
• Some AA decarboxylation and deamination reactions
• Synthesis of neurotransmitters (GABA and serotonin)
• Heme biosynthesis

Deficiency rare - most common in alcoholics

• Anemia
• Peripheral neuropathy/ Seizures

Question 18

Vitamin deficiency responsible for Anemia, Peripheral neuropathy and Seizures?

Answer 18

B6 Pyridoxal

Question 19

Causes of B-Complex Deficiencies?

Answer 19

B Vit Deficiencies uncommon except in severe malnutrition and alcoholism

Question 20

Are B-vitamins always good for you??

Answer 20

NOT protective against lung cancer, may even be harmful for men

Question 21

Roles of Vitamin C?

Resulting Deficiency?

Answer 21

General antioxidant: scavenges free radicals preventing lipid peroxidation and DNA damage

Specific antioxidant: Many Fe and Cu-containing enzymes are dependent on ascorbic acid to maintain metals in the reduced state required for enzyme activity

• Prolyl and lysyl hydroxylases: Collagen synthesis
• Carnitine synthesis: b-oxidation of Fatty acids
• Bile acid synthesis

Deficiency results in Scurvy

Question 22

How does Vitamin D Upregulate Bone Mineralization

Answer 22

Vitamin D undergoes Hydroxylationin liver then the Kidneys becoming Calcitriol => Calcitriol binds receptors in the intestinal mucosa which increases calcium channel expression in lumen of the intestine => Upregulates Bone Mineralization

Question 23

Manifestations of Vitamin D Deficiency in Children/Adults?

Answer 23

Children – Rickets: inadequate bone calcification; soft cartilaginous bones
Adults – Osteomalacia: Brittle bones that break easily

Question 24

Intermediate associated with adverse effects of alcohol?

Answer 24

Acetaldehyde

Question 25

Metabolism of Normal Levels of Alcohol?

Answer 25

Alcohol broken down in cytosol of hepatocytes by Alcohol Dehydrogenase (ADH) to acetaldehyde =>mitochondria for conversion to Acetic Acid by Aldehyde Dehydrogenase (ALDH)

Question 26

Metabolism of Chronic, High Levels of Alcohol?

Answer 26

Tolerance developed: in response to high consumption, additional breakdown of alcohol to acetaldehyde by Alcohol Dehydrogenase (ADH) in microsomal compartment of hepatocytes =>mitochondria for conversion to Acetic Acid by Aldehyde Dehydrogenase (ALDH)

Question 27

What cofactors/Enzymes are essential for alcohol Metabolism?

Answer 27

Alcohol Dehydrogenase (ADH)
Aldehyde Dehydrogenase (ALDH)
NAD+

Question 28

Why is Alcohol considered to be empty calories?

Answer 28

NAD+ diverted from normal metabolism => Excess production of NADH in the liver (NAD+ Key in Kreb’s Cycle and Fatty Acid Oxidation) leading to:

• Decreased gluconeogenesis
• Decreased fatty acid breakdown => accumulation of fat in liver

Question 29

Vitamin Deficiencies commonly seen with chronic alcoholism?

Answer 29

Thiamine (B3), Pyridoxal (B6), Folate (B9)
Vitamin A

Question 30

What does a combination of Alcohol Toxicity and Thiamine (B1)
deficiency lead to? Acute/Chronic manifestations?

Answer 30

Wernicke-Korsakoff Syndrome

• Acute: delirium, ataxia, paralysis of eye muscles
• Chronic: Korsakoff psychosis = severely debilitating short-term
  memory loss. Preventable by thiamine injections.