Nutriotional Biochemistry/Vitamins from First Aid

Question 1

what symptoms do B-complex deficiencies often result in?

Answer 1

dermatitis, glossitis, diarrhea

Question 2

vitamin A (retinol): functions (4)

Answer 2

1. antioxidant
2. constituent of visual pigments (retinal)
3. differentiation of epithelial cells into specialized tissue (pancreatic cells, mucin-secreting cells)
4. prevents squamous metaplasia

Question 3

vitamin A: deficiency (4)

Answer 3

1. night blindness
2. dry, scaly skin
3. corneal degeneration
4. immunosuppression

Question 4

vitamin B1 (thiamine): function (4)

Answer 4

TPP is a cofactor for several dehydrogenases:

1. pyruvate DH (links glycolysis with TCA cycle)
2. alpha-ketoglutarate DH (TCA cycle)
3. transketolase (HMP shunt)
4. branched-chain ketoacid DH

Question 5

vitamin B1 (thiamine): deficiency

Answer 5

Wernicke-Korsakoff syndrome: mental confusion
dry beriberi: polyneuropathy
wet beriberi: dilated cardiomyopathy

Question 6

who typically has vitamin B1 (thiamine) deficiency?

Answer 6

alcoholics and malnourished patients

Question 7

dry beriberi: what is deficient, symptoms

Answer 7

vitamin B1 (thiamine) deficiency; polyneuritis

Question 8

wet beriberi: what is deficient, symptoms

Answer 8

vitamin B1 (thiamine) deficiency; dilated cardiomyopathy

Question 9

vitamin B2 (riboflavin): function

Answer 9

component of FAD and FMN, used as cofactors in redox reactions (e.g., succinate DH reaction in TCA cycle)

Question 10

vitamin B2 (riboflavin) deficiency symptoms

Answer 10

2 C’s of B2: cheilosis, corneal revascularization

Question 11

vitamin B3 (niacin): function

Answer 11

constituent of NAD+, NADP+ (used in redox reactions)

Question 12

where is vitamin B3 (niacin) derived from?

Answer 12

tryptophan

Question 13

pellagra: what is deficient; symptoms (3)

Answer 13

3D’s of B3 (niacin) deficiency:

1. Diarrhea
2. Dementia
3. Dermatitis

Question 14

vitamin B5 (pantothenic acid): function (2)

Answer 14

essential component of coenzyme A (CoA, a cofactor for acetyl transfers) and fatty acid synthase

Question 15

vitamin B5 (pantothenic acid) deficiency symptoms (4)

Answer 15

1. dermatitis
2. enteritis
3. alopecia
4. adrenal insufficiency

Question 16

vitamin B6 (pyridoxine): functions (3)

Answer 16

1. converted to PLP, a cofactor used in transamination, decarboxylation, glycogen phosphorylase
2. synthesis of heme, niacin, histamine
3. synthesis of neurotransmitters (serotonin, epinephrine, norepinephrine, dopamine, GABA)

Question 17

vitamin B6 (pyridoxine) deficiency symptoms (3)

Answer 17

1. convulsions
2. peripheral neuropathy
3. sideroblastic anemia due to impaired hemoglobin synthesis and iron excess

Question 18

vitamin B7 (biotin): function

Answer 18

cofactor for carboxylation enzymes

Question 19

vitamin B7 (biotin) deficiency symptoms (3)

Answer 19

dermatitis, alopecia, enteritis

Question 20

vitamin B9 (folate): function

Answer 20

1. converted to THF, a coenzyme for 1-carbon transfer/methylation reactions
2. important for synthesis of nitrogenous bases in DNA and RNA

Question 21

vitamin B9 (folate) deficiency symptoms (2)

Answer 21

1. macrocytic, megaloblastic anemia (hypersegmented neutrophils)
2. fetal neural tube defects

Question 22

vitamin B12 (cobalamin): function

Answer 22

cofactor for homocysteine methyltransferase and methylmalonyl-CoA mutase; DNA and myelin synthesis

Question 23

vitamin B12 (cobalamin) deficiency: causes (4)

Answer 23

1. insufficient intake (i.e., veganism)
2. malabsorption (e.g., sprue, enteritis, Diphyllobothrium latum)
3. lack of intrinsic factor (pernicious anemia, gastric bypass surgery)
4. absence of terminal ileum

Question 24

vitamin B12 (cobalamin) deficiency symptoms (2)

Answer 24

1. macrocytic, megaloblastic anemia (hypersegmented neutrophils)
2. paresthesias and subacute combined degeneration due to abnormal myelin

Question 25

vitamin C: function (4)

Answer 25

1. antioxidant 2. facilitates iron absorption by reducing it to Fe2+ state 3. hydroxylation of proline and lysine in collagen synthesis 4. dopamine beta-hydroxylase, which converts dopamine to norepinephrine

Question 26

vitamin C: deficiency (2)

Answer 26

1. scurvy: swollen gums, bruising, petechiae, hemarthrosis, anemia, poor wound healing, perifollicular and subperiosteal hemorrhages, "corkscrew" hair 2. weakened immune response

Question 27

list the 4 types of vitamin D

Answer 27

D2: ergocalciferol, ingested from plants D3: cholecalciferol, consumed in milk, formed in sun-exposed skin 25-OH D3: storage form 1,25-(OH)2D3 (calcitriol): active form

Question 28

vitamin D: function

Answer 28

increase intestinal absorption of calcium and phosphate --> increase bone mineralization

Question 29

vitamin D: deficiency in children vs. adults

Answer 29

rickets in children (bone pain and deformity), osteomalacia in adults (bone pain and muscle weakness)

Question 30

vitamin B3 (niacin) deficiency symptoms (2)

Answer 30

glossitis, pellagra

Question 31

vitamin E (tocopherol): function

Answer 31

antioxidant (protects RBCs and membranes from free radical damage)

Question 32

vitamin E (tocopherol) deficiency symptoms (3)

Answer 32

hemolytic anemia, muscle weakness, demyelination

Question 33

vitamin K (phylloquinone): function

Answer 33

cofactor for gamma-carboxylation of glutamic acid residues on various proteins required for blood-clotting; synthesized by intestinal flora

Question 34

vitamin K deficiency: symptom

Answer 34

bleeding

Question 35

vitamins that are substrate carriers

Answer 35

thiamine, pantathenic acid

Question 36

vitamins that are electron transfer molecules

Answer 36

riboflavin, niacin

Question 37

vitamins that are substrate binding

Answer 37

biotin, pyridoxine

Question 38

vitamins that are hematopoietic

Answer 38

folate, B12

Question 39

vitamins involved in posttranslational modification

Answer 39

vitamin K and C

Question 40

antioxidant vitamins

Answer 40

vitamin C, E, and carotene (provitamin A)

Question 41

zinc: function (2)

Answer 41

wound healing, component of hundreds of enzymes