Vitamins and minerals

Question 1

Vitamin A

Answer 1

1mg retinol or 6mg B-carotene; important for the maintenance of reproduction and vision, promotion of growth, differentiation and maintenance of epithelial tissue

Question 2

Vitamin A deficiency and toxicity

Answer 2

Deficiency = night blindness, keratinization of epithelial cells; toxicity = excessive intake causes skin to become dry and pruritic (itchy), liver enlarged, rise in intracranial pressure

Question 3

Thiamine (Vitamin B1)

Answer 3

1.5 mg/day; converted to thiamine pyrophosphate; ATP (Alpha-keto glutarate dehydrogenase, Transketolase, Pyruvate dehydrogenase)

Question 4

Beri-beri

Answer 4

deficiency of B1; dry beri beri = polyneuritis, symmetrical muscle wasting; wet beri beri = high output cardiac failure, edema

Question 5

Wernicke’s encephalopathy

Answer 5

common in alcoholic caused by thiamine deficiency -> confusion, ataxia, vision changes like nystagmus (back and forth movements) and double vision

Question 6

Korsakoff psychosis

Answer 6

common in alcoholic caused by thiamine deficiency -> loss of memory, inability to form new ones, make up stories, hallucinations

Question 7

Riboflavin (Vitamin B2)

Answer 7

1.7 mg/day; precursor for the coenzymes, FMN and FAD

Question 8

Riboflavin (Vitamin B2) deficiency

Answer 8

skin lesions, red tongue, cheliosis (chapped and fissured lips), angular stomatitis (inflammation of the corners of the mouth)

Question 9

Niacin (Vitamin B3)

Answer 9

19 mg/day; as nicotinic acid or nicotinamide it is a precursor for the coenzymes NAD and NADP

Question 10

Niacin (Vitamin B3) deficiency

Answer 10

Pellagra (3Ds of B3: dermatitis, diarrhea, dementia, and if severe, death)

Question 11

Pantothenic acid (Vitamin B5)

Answer 11

Not established, maybe 5-10 mg/day; precursor of pantotheine, forms part of CoA (AMP + pantothenic acid + cysteamine)

Question 12

Pyridoxine (Vitamin B6)

Answer 12

2 mg/day; pyridoxine (pyridoxol) is a precursor of pyridoxal phosphate which is a coenzyme for enzymes catalyzing transamination (ALT and AST), decarboxylation (catecholamines, GABA, histamine), and for glycogen phosphorylase

Question 13

Pyridoxine (Vitamin B6) deficiency

Answer 13

dermatitis, convulsion, microcytic anemia

Question 14

Isoniazid

Answer 14

used to treat TB; similar structure to pyroxidine, leading to pyroxidine (vitamin B6) deficiency

Question 15

Biotin (Vitamin B7)

Answer 15

no established RDA; acts as coenzyme in carboxylation reactions in covalent linkage to lysine side chains of enzymes (pyruvate carboxylase in gluconeogenesis, acetyl-CoA carboxylase, propionyl-CoA carboxylase)

Question 16

Biotin (Vitamin B7) deficiency

Answer 16

avidin from raw eggs can cause biotin deficiency -> dermatitis, anorexia, nausea, muscle pain

Question 17

Folic acid (Vitamin B9)

Answer 17

400 ug/day; precursor for tetrahydrofolate that is used as a carrier of one carbon units at different levels of oxidation

Question 18

Folic acid (Vitamin B9) deficiency

Answer 18

megaloblastic anemia, GI disturbances; infants born from folic acid deficient women are at risk for neural tube defects

Question 19

Sulfanilamide (and other sulfonamides)

Answer 19

antibiotics that competitively inhibit dihydropteroate synthetase in the folic acid synthesis of microorganims -> can not synthesize nucleotides needed for their replication

Question 20

Methotrexate, aminopterin

Answer 20

competitively inhibits dihydrofolate reductase preventing the formation of tetrahydrofolic acid; used in acute leukemia in children

Question 21

Trimethoprim

Answer 21

antibiotic that selectively inhibits prokaryotic dihydrofolate reductase

Question 22

“Folate trap”

Answer 22

B12 deficiency causes the THF can end up irreversibly in the Methyl-THF form -> no THF for reactions

Question 23

Vitamin B12 (cobalamin)

Answer 23

3 ug/day; complex multiple ring structure which includes a cobalt atom, used in methylmalonyl CoA isomerase (breakdown of some amino acids, odd chain FA) and homocysteine:tetrahydrofolate methyl transferase

Question 24

Vitamin B12 (cobalamin) deficiency

Answer 24

pernicious anemia (with megaloblastic anemia, but caused by lack of intrinsic factors) and degeneration of spinal cord neurons; need to intramuscularly inject this vitamin

Question 25

Vitamin C (ascorbic acid)

Answer 25

60mg/day; water soluble antioxidant and it promotes the hydroxylation of proline residues of collagen. Ascorbic acid is also required in the synthesis of carnitine, norepinephrine (from dopamine), and bile acids.

Question 26

Vitamin C (ascorbic acid) deficiency

Answer 26

Scurvy (hemorrhage, impaired wound healing, and bone formation)

Question 27

Vitamin D

Answer 27

15 ug/day; regulation of calcium levels through actions on the intestine, kidney, and bone. Requires conversion to 1,25-dihydroxy vitamin D3 to form active compound

Question 28

Vitamin D deficiency

Answer 28

Deficiency -> rickets (defective mineralization) osteomalacia (softening of bones)

Question 29

Vitamin E (tocopherol)

Answer 29

10mg/day; lipid-soluble antioxidant and helps prevent lipid damage

Question 30

Vitamin E (tocopherol) deficiency

Answer 30

associated with lysis of erythrocytes; rare state can lead to mild neurological dysfunction

Question 31

Vitamin K

Answer 31

no RDA but 70-140 ug; coenzyme for the carboxylation of glutamic acid side chains of some blood clotting factors (factors II, VII, IX, X ->1972, watergate scandal)

Question 32

Vitamin K deficiency

Answer 32

prolonged blood clotting times

Question 33

Fat soluble vitamins

Answer 33

Vitamin a, d, e, k

Question 34

Water soluble vitamins

Answer 34

Vitamin b, c

Question 35

6 macro-minerals

Answer 35

calcium, chloride, magnesium, phosphorus, potassium, sodium

Question 36

9 trace minerals

Answer 36

copper, fluoride, iron, iodine, selenium, zinc, chromium, manganese, molybdenum

Question 37

Possibly essential trace minerals

Answer 37

arsenic (+5), boron, nickel, silicon, vanadium

Question 38

Most comon mineral deficiencies in the world

Answer 38

Iron, iodine, zinc

Question 39

Acrodermatitis Enteropathica

Answer 39

autosomal recessive; mutation in Zip4 zinc transporter gene with poor zinc absorption in the jejunum -> skin lesions, diarrhea, alopecia, growth retardation, delayed sexual maturation, impaired immunity and infection

Question 40

Severe zinc deficiency

Answer 40

skin lesions, diarrhea, alopecia, anorexia

Question 41

Zinc effect on copper

Answer 41

zinc reduces intestinal absorption of copper

Question 42

Wilson_s disease

Answer 42

autosomal recessive, toxicity from high organ copper levels (liver, brain, kidneys) -> skin lesions, alopecia; treat with penicillamine with high dose zinc

Question 43

Copper deficiency

Answer 43

very rare (zinc-induced by supplementation or denture creams, gastrectomy, GI disease) -> microcytic anemia, neuropathy, neutropenia, leukopenia

Question 44

Hemochromatosis

Answer 44

excess GI iron absorption, mostly seen in men > 35 years old; non-specific, bronze skin -> liver cirrhoisis/carcinoma; treat by reducing iron and ethanol, phlebotomy

Question 45

Iron deficiency

Answer 45

Prevalence particularly in the young (1-2 years old) and in menstruating women (16-49) because menstruation causes loss of iron

Question 46

Iodine deficiency

Answer 46

Deficiency causes enlarged thyroid (goiter), impaired growth, severe mental retardation (cretinism); probably increases risk for follicular cancer

Question 47

Iodine toxicity

Answer 47

possibly increases risk for papillary cancer

Question 48

Food fortification may benefit some members of a population, but provide no benefit or even adversely affect others in the population

Answer 48

Elderly have high iron stores but iron fortification is good for young children, teenage girls, fertile and pregnant women; iodine prevents cretinism/ impaired growth but overdose can affect thyroid function and cancer risk