Vitamins - Water Soluble (Krasowski)

Question 1

this vitamin is a highly pigemented yellow compound found in eggs, meat, milk and leafy green vegetables, and is stable to heat but degrades in milk if left in the sunlight

Answer 1

riboflavin (vitamin B2)

Question 2

vitamin found in meat, poultry, fish, potatoes and vegetables that is involved in pathways that synthesize amino acids

Answer 2

pyridoxine (vitamin B6)

Question 2

intravenous formulation of this vitamin is used to treat warfarin poisoning

Answer 2

vitamin K

Question 3

vitamin that is not endogenously made, rarely is deficient in the diet, and functions as an anti-oxidant that promotes the absorption of non-heme iron and the synthesis of collagen

Answer 3

vitamin C

Question 3

what do elevated levels of homocysteine and methylmalonic acid indicate?

Answer 3

functional vitamin B12 deficiency

Question 4

this condition is characterized by deficiency of intrinsic factor (IF), secondary to gastric dystrophy, an autoimmune disorder

Answer 4

pernicious anemia

Question 4

this vitamin, whose functional activation requires vitamin B12, is a precursor to THF and is found in liver and leafy green vegetables

Answer 4

folate

Question 5

peripheral neuropathy and hemorrhaging into the mamillary bodies are symptoms characteristic of what disease, that afflicts alcoholics?

Answer 5

dry beriberi

Question 6

though vitamin C toxicity is rare, high doses can acidify the urine, and more seirously may promote iron overload in patients with what diseases?

Answer 6

thalassemia, in which unbound iron is already circulating in the blood in elevated amounts because of improper hemoglobin formation and hemachromatosis, a disorder in which iron is excessively absorbed

Question 7

what is the role of intrinsic factor (IF) in the asorption of vitamin B12?

Answer 7

Absorption of B12 requires IF, which is secreted in excess quantities in the stomach. IF/B12 complexes form and B12 is absorbed in the ileum

Question 8

this vitamin does not have a deficiency or toxicity syndrome associated with it, but is a coenzyme involved in many biological processes including gluconeogenesis, fatty acid synthesis and amino acid catabolism

Answer 8

biotin

Question 8

intravenous formulation of this vitamin is used to treat wernicke-korsakoff syndrome

Answer 8

thiamine

Question 9

principal sources of this vitamin are meat, eggs and dairy, and up to 2/3 of the vegetarian/vegan population is deficient

Answer 9

cobalamine (vit b12)

Question 11

alcoholics, the elderly, and pregnant women are at risk for developing these two forms of thiamine deficiency

Answer 11

dry beriberi: poor appetite, fatigue, peripheral neuritis

wet beriberi: edema and cardiac failure

Question 12

deficiency in this vitamin may cause, among pulmonary, GI and metabolic symptoms, an inability to produce sound (aphonia)

Answer 12

thiamine (B1)

Question 13

vitamin that is easily leeched out of food by boiling and is transported in plasma as thiamine

Answer 13

vitamin B1

Question 13

deficiency of this vitamin in infants causes irritability, seizures and vomiting, and peripheral neuropathy in adults

Answer 13

vitamin B6

Question 14

vitamin that is active in mainly redox reactions, and exists in its active form as a cofactor (e.g., FMN and FAD)

Answer 14

riboflavin (vitamin B2)

Question 16

How is it that carcinoid tumors can predispose to a niacin deficiency?

Answer 16

this is due to carcinoma’s accelerated tryptophan metabolism (to serotonin), since tryptophan is another route by which NAD and NADP can be made

Question 16

these are two of the most common therapeutic uses for vitamin B6

Answer 16

hyperemesis gravidarum

seizure control in early childhood seizure syndromes

Question 18

symptoms of this disease include systemic problems such as fatigue, syncope and a variety of cutaneous problems like xerosis, ecchymoses, gum abnormalities and poor wound healing

Answer 18

scurvy

Question 20

a flabby, dilated heart and edema are symptoms characteristic of what disease that may affect pregnant women who present with high output cardiac failure?

Answer 20

wet beriberi (resulting from thiamine deficiency)

Question 22

this vitamin is essential (must be obtained from the diet) but is so widely available in food that a deficiency has never been described

Answer 22

pantothenic acid (vitamin B5)

Question 24

intramuscular injections of this vitamin are used in the lifelong management of pernicious anemia

Answer 24

vitamin B12

Question 25

Which of the following vitamin deficiencies would be MOST common in a strict vegetarian who does not eat eggs? A. Vitamin C B. Riboflavin C. Folic acid D. Vitamin B6 E. Vitamin B12

Answer 25

E. Vegetarians are at high risk of vitamin B12 deficiency. One possible source of B12 is vegan B12-fortified yeast.

Question 26

these two drugs antagonize pyridoxine (vitamin B6), which is why B6 supplementation is recommended in patients receiving these drugs chronically

Answer 26

isoniazid (TB medication); penicillamine (chelator)

Question 27

aspirins or other NSAIDs are often given to ward off the unpleasant side effects of this drug, which, when given in high doses is extremely effective in treating lipid disorders

Answer 27

niacin (vitamin B3)

Question 28

vitamin that is active in redox reactions, is used in high doses to treat lipid disorders, and exists in its active form as a cofactor (e.g., NAD and NADP)

Answer 28

niacin (aka vitamin B3, aka nicotinic acid)

Question 28

niacin deficiency is clinically known as ______, and is associated with ‘three Ds’. what are they?

Answer 28

pellagra; diarrhea, dementia, dermatitis

Question 29

B12 is carried in the plasma by what carrier proteins?

Answer 29

transcobalmins

Question 30

deficiency in this vitamin often takes several years to build up, and its symptoms (e.g., megaloblastic anemia, neurologic changes and subacute degeneration of the spinal cord) are often masked be adequate folic acid intake

Answer 30

vitamin B12

Question 32

angular stomatitis (mouth lesions) and glossitis (tongue swelling with redness) are symptoms associated with deficiency of this vitamin, which is strongly associated with poor diet and poverty

Answer 32

riboflavin (vitamin B2) these symptoms are also present in niacin deficiency, which can present similarly

Question 33

syndrome that is exacerbated by magnesium deficiency that is characterized by confusion, ataxia, and confabulation

Answer 33

wernicke-korsakoff syndrome

Question 34

what three biochemical reactions is vitamin B12 involved in?

Answer 34

1. conversion of methyl-THF to THF (for purine/pyrimidine synthesis) 2. secondary conversion of homocysteine to methionine 3. conversion of methylmalonyl CoA to succinyl CoA

Question 35

why is bleeding and poor wound healing common in scurvy?

Answer 35

vitamin C is needed for the hydroxylation of procallagen, to provide tensile support to the vasculature. without it, vessels are weak and prone to leak