Vitamins

Question 1

Vitamin A

Functions

Answer 1

Vision-black and white; night vision

Cell differentiation

Question 2

Vitamin A

Deficiency

Answer 2

Mild: night blindness
Severe:
-xerophthalmia (damage to cornea, dry eyes, scarring, blindness)
-hyperkeratosis (increased keratin synthesis)
-infection

Question 3

Vitamin D

Functions

Answer 3

Calcium homeostasis

Gene expression and cell differentiation

Question 4

Vitamin D

Source

Answer 4

• Synthesized from UV light
• Some dietary intake
• 2 forms

Question 5

Vitamin D

Deficiency

Answer 5

• deficiency in childhood can lead to rickets
• deficiency in adulthood can lead to osteopenia and osteoporosis
• can cause hyperintense signal near ventricles (may lead to Alzheimer’s and dementia?)

Question 6

Vitamin K

Functions

Answer 6

• blood clotting (needed to convert prothrombin to thrombin)
• bone calcification to make hydroxyapatite

Question 7

Vitamin K

Deficiency

Answer 7

• uncontrollable bleeding

- give newborns vitamin K shot (because don’t yet have colonic bacteria needed to make vitamin K

Question 8

Vitamin E

Function

Answer 8

Antioxidant
Sits in membranes and scavenges free radicals to prevent damage
Interacts with vitamin C…vitamin E transfers free radical to vitamin C which decreases the reactivity of it

Question 9

Vitamin E deficiency

Answer 9

Hemolytic anemia-ruptured RBCs due to oxidative damage

Question 10

Vitamin C

Functions

Answer 10

• antioxidant…needed for gutathione peroxidase in order to convert free radicals into water
• synthesis of molecules, especially collagen
• can reduce iron, copper, and chromium so it can be better absorbed (have to convert non-heme Fe3+ to Fe2+ in oder to absorb it)

Question 11

Vitamin C

Deficiency

Answer 11

Scurvy (bleeding gums, poor wound healing, internal hemorrhaging)

Question 12

“ATP” B-Vitamins

Answer 12

B1 (thiamin)
B2
B3
B5
B7

Question 13

B1 (thiamine)

Function

Answer 13

Thiamine 
ATP production (conversion of pyruvate to acetyl CoA); coenzyme TPP
RNA/DNA synthesis
NADPH synthesis
Nerve function

Question 14

B1 (thiamine)

Deficiency

Answer 14

Beri Beri:

1. Dry: muscle wasting, leg cramps, neuropathy
2. Wet: edema, heart enlargement
3. Infantile: breast milk is thiamine deficient
4. Cerebral=Wernicke-Korsakoff caused by alcoholism; involuntary movement and paralysis of eye

Heart failure with B1 levels at suboptimal status

Question 15

B2 (riboflavin)

Functions

Answer 15

Riboflavin

Energy production (needed in Krebs); part of FAD and FMN
Synthesis of vitamins
NT metabolism
Shown to maybe reduce systolic and diastolic BP

Question 16

B2 (riboflavin)

Deficiency

Answer 16

Rarely an isolated deficiency

Causes muscle weakness, cheilosis, stomatitis, glossitis

Question 17

B3 (niacin)

Functions

Answer 17

Niacin

ATP production (glycolysis and Krebs) part of NAD and NADP
Synthesis and metabolism of fatty acids, cholesterol, steroid hormones, DNA, vitamin C, folate

Decreases LDL and increases HDL, but side effects include flushing and itching

Question 18

B3 (niacin)

Deficiency

Answer 18

Niacin

Pellegra: the 4 D’s (dermatitis, diarrhea, dementia, death)

Question 19

B5 (panthenoic acid)

Function

Answer 19

Pantothenic Acid

Part of CoA

ATP production (glycolysis and Kreb’s)

Synthesis of heme, cholesterol, bile salts, phospholipids, fatty acids, steroid hormones)

Question 20

B7 (biotin)

Function

Answer 20

Biotin

Gluconeogenesis
Protein Catabolism
Fatty acid synthesis
ATP production

Question 21

B7 (biotin)

Deficiency

Answer 21

Uncommon, but could be caused by eating a lot of raw eggs (avidin), intestinal diseases

Question 22

One Carbon Metabolism B-Vitamins

Answer 22

B6, 9, 12

Question 23

Isoniazid

Answer 23

• drug used for tuberculosis treatment

- can cause B6 (pyridoxine) deficiency (and thus cause niacin deficiency)

Question 24

B6 (pyroxidine)

Function

Answer 24

Pyroxidine

Part of coenzymes used in amino acid and fatty acid metabolism (transaminases, decarboxylases)

Needed for heme synthesis!

One-carbon metabolism (synthesis of cysteine is dependent on on B6 or else there will be a buildup of homocysteine)

Question 25

B9 | Function

Answer 25

Folate Activates B12 Helps synthesize DNA for new cell growth, protects nerve cells

Question 26

B6 deficiency (pyroxidine)

Answer 26

Pyroxidine Microcytic, hypochromic anemia (can't make heme without B6) Convulsions (can't make NTs) Hyperhomocysteinemia-can't breakdown homocysteine so risk of vascular disease increases.

Question 27

B9 (folate) | Function

Answer 27

Folate Synthesis of RNA and DNA through production of nucelotides (T, A, G) Conversion of homocysteine to methionine SAM synthesis in order to methylate (universal methyl donor)

Question 28

B9 (folate) | Deficiency

Answer 28

Folate Macrocytic/megaloblastic anemia (inhibited DNA synthesis)-large RBCs and increased number of lobes in PMNs (polymorphonucelear leukocytes) Hyperhomocysteinemia because can't metabolism homocysteine...increases risk of vascular disease and dementia Neural tube defects (spina bifida and anencephaly) Take folic acid supplement

Question 29

B9 (folate) | Toxicity

Answer 29

May mask B12 deficiency | May cause cancer growth

Question 30

B12 (cobalamine) | Function

Answer 30

Cobalamin DNA and RNA synthesis by production of thymidine, adenine and guanine Methionine recycling-conversion of homocystine to methionine SAM synthesis Odd-chain fatty acid metabolism

Question 31

B12(cobalamine) | Deficiency and causes

Answer 31

Cobalamine Macrocytic anemia (large RBCs and multilobed PMN) Hyperhomocrysteinemia Neurological disease (degeneration of spinal cord and brain, neuropathy) Can be caused by dietary deficiency, pernicious anemia (can't make IF so can't absorb B12), and atrophic gastritis (can't separate B12 from food so it can't be absorbed)

Question 32

Pernicious Anemia

Answer 32

Autoimmune disorder causing a loss of intrinsic factor in stomach Causes B12 deficiency

Question 33

Deficiencies in what vitamins cause microcytic anemia?

Answer 33

B6 | Iron

Question 34

Deficiencies in what vitamins cause microcytic anemia?

Answer 34

B9-folate | B12-cobalamine

Question 35

Absorption of B12

Answer 35

Cobalamine 1. Ingested and enters stomach with haptocorrin that is in the saliva 2. In stomach, B12 separated from food; IF is released 3. In duodenum, B12 is released from haptocorrin and binds to IF 4. B12 and IF are absorbed by enterocyte in ileum