FIRST AID USMLE STEP 1 – VITAMINS QUESTIONS WITH
CORRECT ANSWERS (LATEST UPDATE)
Vitamin A (retinol) - Function - ANSWER-Antioxidant; constituent of visual pigments
(retinal); essential for normal differentiation of epithelial cells into specialized tissue
(pancreatic cells, mucus-secreting cells); prevents squamous metaplasia. Used to treat
measles and acute promyelocytic leukemia (APL).
Vitamin A (retinol) - Deficiency - ANSWER-Night blindness (nyctalopia); dry, scaly skin
(xerosis cutis); corneal degeneration (keratomalacia); Bitot spots on conjunctiva;
immunosuppression.
Vitamin A (retinol) - Excess - ANSWER-Acute toxicity—nausea, vomiting, vertigo, and
blurred vision. Chronic toxicity—alopecia, dry skin (eg, scaliness), hepatic toxicity and
enlargement, arthralgias, and pseudotumor cerebri. Teratogenic (cleft palate, cardiac
abnormalities), therefore a ⊝ pregnancy test and two forms of contraception are
required before isotretinoin (vitamin A derivative) is prescribed.
Vitamin A (retinol) - Extra - ANSWER-Retinol is vitamin A, so think retin-A (used
topically for wrinkles and Acne). Found in liver and leafy vegetables. Use oral
isotretinoin to treat severe cystic acne. Use all-trans retinoic acid to treat acute
promyelocytic leukemia. Isotretinoin is teratogenic.
Vitamin B1 (thiamine) - Function - ANSWER-In thiamine pyrophosphate (TPP), a
cofactor for several dehydrogenase enzyme reactions: +Pyruvate dehydrogenase (links
glycolysis to TCA cycle) +α-ketoglutarate dehydrogenase (TCA cycle) +Transketolase
(HMP shunt) +Branched-chain ketoacid dehydrogenase
Vitamin B1 (thiamine) - Deficiency - ANSWER-Impaired glucose breakdown p ATP
depletion worsened by glucose infusion; highly aerobic tissues (eg, brain, heart) are
affected first. In alcoholic or malnourished patients, give thiamine before dextrose to
reduce risk of precipitating Wernicke encephalopathy. Diagnosis made by increase in
RBC transketolase activity following vitamin B1 administration.
Vitamin B1 (thiamine) - Extra - ANSWER-Think ATP: α-ketoglutarate dehydrogenase,
Transketolase, and Pyruvate dehydrogenase. Spell beriberi as Ber1Ber1 to remember
vitamin B1. Wernicke-Korsakoff syndrome —confusion, ophthalmoplegia, ataxia (classic
triad) + confabulation, personality change, memory loss (permanent). Damage to medial
dorsal nucleus of thalamus, mammillary bodies. Dry beriberi —polyneuritis, symmetrical
muscle wasting. Wet beriberi —high-output cardiac failure (dilated cardiomyopathy),
edema.
Vitamin B2 (riboflavin) - Function - ANSWER-Component of flavins FAD and FMN, used
as cofactors in redox reactions, eg, the succinate dehydrogenase reaction in the TCA
cycle.
, Vitamin B2 (riboflavin) - Deficiency - ANSWER-Cheilosis (inflammation of lips, scaling
and fissures at the corners of the mouth), Corneal vascularization.
Vitamin B2 (riboflavin) - Extra - ANSWER-FAD and FMN are derived from riboFlavin
(B2 ≈ 2 ATP). The 2 C's of B2 .
Vitamin B3 (niacin) - Function - ANSWER-Constituent of NAD+, NADP+ (used in redox
reactions). Derived from tryptophan. Synthesis requires vitamins B2 and B6 . Used to
treat dyslipidemia; lowers levels of VLDL and raises levels of HDL.
Vitamin B3 (niacin) - Deficiency - ANSWER-Glossitis. Severe deficiency leads to
pellagra, which can be caused by Hartnup disease, malignant carcinoid syndrome (
increased tryptophan metabolism), and isoniazid ( decreased vitamin B6). Symptoms of
pellagra: Diarrhea, Dementia (also hallucinations) , Dermatitis (C3/C4 dermatome
circumferential "broad collar" rash [Casal necklace], hyperpigmentation of sun- exposed
limbs A ).
Vitamin B3 (niacin) - Excess - ANSWER-Facial flushing (induced by prostaglandin, not
histamine; can avoid by taking aspirin with niacin), hyperglycemia, hyperuricemia.
Vitamin B3 (niacin) - Extra - ANSWER-NAD derived from Niacin (B3 ≈ 3 ATP). The 3
D's of B3 . Hartnup disease —autosomal recessive. Deficiency of neutral amino acid
(eg, tryptophan) transporters in proximal renal tubular cells and on enterocytes ->
neutral aminoaciduria and decreased absorption from the gut -> increased tryptophan
for conversion to niacin -> pellagra-like symptoms. Treat with high-protein diet and
nicotinic acid
Vitamin B5 (pantothenic acid) - Function - ANSWER-Essential component of coenzyme
A (CoA, a cofactor for acyl transfers) and fatty acid synthase.
Vitamin B5 (pantothenic acid) - Deficiency - ANSWER-Dermatitis, enteritis, alopecia,
adrenal insufficiency.
Vitamin B5 (pantothenic acid) - Extra - ANSWER-B5 is " pento" thenic acid.
Vitamin B6 (pyridoxine) - Function - ANSWER-Converted to pyridoxal phosphate (PLP),
a cofactor used in transamination (eg, ALT and AST), decarboxylation reactions,
glycogen phosphorylase. Synthesis of cystathionine, heme, niacin, histamine, and
neurotransmitters including serotonin, epinephrine, norepinephrine (NE), dopamine, and
GABA.
Vitamin B6 (pyridoxine) - Deficiency - ANSWER-Convulsions, hyperirritability, peripheral
neuropathy (deficiency inducible by isoniazid and oral contraceptives), sideroblastic
anemias due to impaired hemoglobin synthesis and iron excess.
CORRECT ANSWERS (LATEST UPDATE)
Vitamin A (retinol) - Function - ANSWER-Antioxidant; constituent of visual pigments
(retinal); essential for normal differentiation of epithelial cells into specialized tissue
(pancreatic cells, mucus-secreting cells); prevents squamous metaplasia. Used to treat
measles and acute promyelocytic leukemia (APL).
Vitamin A (retinol) - Deficiency - ANSWER-Night blindness (nyctalopia); dry, scaly skin
(xerosis cutis); corneal degeneration (keratomalacia); Bitot spots on conjunctiva;
immunosuppression.
Vitamin A (retinol) - Excess - ANSWER-Acute toxicity—nausea, vomiting, vertigo, and
blurred vision. Chronic toxicity—alopecia, dry skin (eg, scaliness), hepatic toxicity and
enlargement, arthralgias, and pseudotumor cerebri. Teratogenic (cleft palate, cardiac
abnormalities), therefore a ⊝ pregnancy test and two forms of contraception are
required before isotretinoin (vitamin A derivative) is prescribed.
Vitamin A (retinol) - Extra - ANSWER-Retinol is vitamin A, so think retin-A (used
topically for wrinkles and Acne). Found in liver and leafy vegetables. Use oral
isotretinoin to treat severe cystic acne. Use all-trans retinoic acid to treat acute
promyelocytic leukemia. Isotretinoin is teratogenic.
Vitamin B1 (thiamine) - Function - ANSWER-In thiamine pyrophosphate (TPP), a
cofactor for several dehydrogenase enzyme reactions: +Pyruvate dehydrogenase (links
glycolysis to TCA cycle) +α-ketoglutarate dehydrogenase (TCA cycle) +Transketolase
(HMP shunt) +Branched-chain ketoacid dehydrogenase
Vitamin B1 (thiamine) - Deficiency - ANSWER-Impaired glucose breakdown p ATP
depletion worsened by glucose infusion; highly aerobic tissues (eg, brain, heart) are
affected first. In alcoholic or malnourished patients, give thiamine before dextrose to
reduce risk of precipitating Wernicke encephalopathy. Diagnosis made by increase in
RBC transketolase activity following vitamin B1 administration.
Vitamin B1 (thiamine) - Extra - ANSWER-Think ATP: α-ketoglutarate dehydrogenase,
Transketolase, and Pyruvate dehydrogenase. Spell beriberi as Ber1Ber1 to remember
vitamin B1. Wernicke-Korsakoff syndrome —confusion, ophthalmoplegia, ataxia (classic
triad) + confabulation, personality change, memory loss (permanent). Damage to medial
dorsal nucleus of thalamus, mammillary bodies. Dry beriberi —polyneuritis, symmetrical
muscle wasting. Wet beriberi —high-output cardiac failure (dilated cardiomyopathy),
edema.
Vitamin B2 (riboflavin) - Function - ANSWER-Component of flavins FAD and FMN, used
as cofactors in redox reactions, eg, the succinate dehydrogenase reaction in the TCA
cycle.
, Vitamin B2 (riboflavin) - Deficiency - ANSWER-Cheilosis (inflammation of lips, scaling
and fissures at the corners of the mouth), Corneal vascularization.
Vitamin B2 (riboflavin) - Extra - ANSWER-FAD and FMN are derived from riboFlavin
(B2 ≈ 2 ATP). The 2 C's of B2 .
Vitamin B3 (niacin) - Function - ANSWER-Constituent of NAD+, NADP+ (used in redox
reactions). Derived from tryptophan. Synthesis requires vitamins B2 and B6 . Used to
treat dyslipidemia; lowers levels of VLDL and raises levels of HDL.
Vitamin B3 (niacin) - Deficiency - ANSWER-Glossitis. Severe deficiency leads to
pellagra, which can be caused by Hartnup disease, malignant carcinoid syndrome (
increased tryptophan metabolism), and isoniazid ( decreased vitamin B6). Symptoms of
pellagra: Diarrhea, Dementia (also hallucinations) , Dermatitis (C3/C4 dermatome
circumferential "broad collar" rash [Casal necklace], hyperpigmentation of sun- exposed
limbs A ).
Vitamin B3 (niacin) - Excess - ANSWER-Facial flushing (induced by prostaglandin, not
histamine; can avoid by taking aspirin with niacin), hyperglycemia, hyperuricemia.
Vitamin B3 (niacin) - Extra - ANSWER-NAD derived from Niacin (B3 ≈ 3 ATP). The 3
D's of B3 . Hartnup disease —autosomal recessive. Deficiency of neutral amino acid
(eg, tryptophan) transporters in proximal renal tubular cells and on enterocytes ->
neutral aminoaciduria and decreased absorption from the gut -> increased tryptophan
for conversion to niacin -> pellagra-like symptoms. Treat with high-protein diet and
nicotinic acid
Vitamin B5 (pantothenic acid) - Function - ANSWER-Essential component of coenzyme
A (CoA, a cofactor for acyl transfers) and fatty acid synthase.
Vitamin B5 (pantothenic acid) - Deficiency - ANSWER-Dermatitis, enteritis, alopecia,
adrenal insufficiency.
Vitamin B5 (pantothenic acid) - Extra - ANSWER-B5 is " pento" thenic acid.
Vitamin B6 (pyridoxine) - Function - ANSWER-Converted to pyridoxal phosphate (PLP),
a cofactor used in transamination (eg, ALT and AST), decarboxylation reactions,
glycogen phosphorylase. Synthesis of cystathionine, heme, niacin, histamine, and
neurotransmitters including serotonin, epinephrine, norepinephrine (NE), dopamine, and
GABA.
Vitamin B6 (pyridoxine) - Deficiency - ANSWER-Convulsions, hyperirritability, peripheral
neuropathy (deficiency inducible by isoniazid and oral contraceptives), sideroblastic
anemias due to impaired hemoglobin synthesis and iron excess.
