Water Soluble (B) Vitamins

Question 1

Vitamin B1 (name, function, diagnosis)

Answer 1

Thiamine
Cofactor for dehydrogenases
Diagnosed by increase in RBC transketolase activity following B1 administration

Question 2

Thiamine Deficiency (who, general, 3 syndromes)

Answer 2

Alcoholism/malnutrition
Impaired glucose breakdown - ATP depletion worsened by glucose infusion
Wernicke-Korsakoff syndrome - confusion, opthalmoplegia, ataxia (classic triad) plus confabulaiton/memory loss. Dmaage to medial dorsal nucleus of thalamus and mammary bodies
Dry Beriberi - polyneuritis (wrist/foot drop), symmetrical muscle wasting. Polished rice only diet
Wet Beriberi - peripheral vasodilation causing high output cardiac failure (dilated cardiomyopathy)/edema

Question 3

Vitamin B2 (2 active forms, function, 2 deficiency)

Answer 3

FAD and FMN, used as cofactors in redox reactions

2 Cs of B2: Cheilosis (angular stomatitis), corneal vascularization

Question 4

5 Deficiencies Causing Angular Stomatitis

Answer 4

B2, B3, B9, B12, Fe

Question 5

Vitamin B3 (name, active forms/function, used to treat, excess, deficiency)

Answer 5

Niacin
NAD+ and NADP+ used in redox reactions
Used to treat dyslipidemia because lowers VLDL/LDL and raises HDL
Excess can cause facial flushing via PGE mech, can avoid via aspirin
Deficiency gives pellagra with 3 Ds - Diarrhea, Dementia, Dermatitis (broad collar rash)

Question 6

Vitamin B5 (name, function, deficiency)

Answer 6

Pantothenic acid
Component of CoA used as cofactor for acyl transfers and fatty acid synthesis
Dermatitis, alopecia, others

Question 7

Vitamin B6 (name, active form, function, deficiency)

Answer 7

Pyridoxine
Pyridoxal phosphate, cofactor used in transamination to make a lot of shit including a lot of NTs/GABA
Deficiency kinda like Riboflavin, but with CONVULSIONS (lack GABA) and hyperirritability

Question 8

Vitamin B7 (name function, deficiency and deficiency causes)

Answer 8

Biotin
Cofactor for carboxylation reactions
Defiency rare, can be caused by avidin in egg whites or antibiotics
Dermatitis, alopecia, etc

Question 9

2 Deficiencies Isoniazid Can Give

Answer 9

B6 and B3

Question 10

B9 (name, active form, function, deficiency)

Answer 10

Folate
Converted to THF, a coenzyme for 1C/methylation reactions for the synthesis of purines/pyrimidines
Macrocytic, megaloblastic anemia with hyperseg PMNs but WITHOUT neuro symptoms like B12
NTD in utero and growth failure growing up

Question 11

B9/B12 Deficiency Associations

Answer 11

Excess of folate can cause B12 deficiency (or exacerbate), but B12 deficiency can cause folate deficiency

Question 12

Vitamin B12 (name, function and 2 reactions, deficiency, deficiency causes)

Answer 12

Cobalimin (has cobalt)
Cofactor for homocysteine methyltransferase (converts homocysteine + THF-CH3 to methionine and THF. SAM regenerates) and methylmalonyl-CoA mutase (changes methylmalonyl CoA to succinyl CoA, can go to TCA or heme synth)
Macrocytic, megaloblastic anemia with hypersegmented PMNs and subacute degeneration/demyelination of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts)
Deficiency by no intake over loooong period of time (veganism), autoAbs against IF producing cells in gastric, or terminal ileum resection or damage (CD, celiac)