Biochemistry - Nutrition Flashcards
Calcium homeostasis is associated with which fat-soluble vitamin?
Vitamin D
Clotting factor synthesis depends on which fat-soluble vitamin?
Vitamin K
Which fat-soluble vitamin acts as an antioxidant?
Vitamin E
Which groups of vitamins are water soluble?
B vitamins and Vit C
Is vitamin C fat soluble or water soluble?
Water soluble
Is thiamine fat soluble or water soluble?
Water soluble
Is riboflavin fat soluble or water soluble?
Water soluble
Is pantothenic acid fat soluble or water soluble?
Water soluble
Is cobalamin fat soluble or water soluble?
Water soluble
Are pyridoxine, pyridoxal, and pyridoxamine fat soluble or water soluble?
Water soluble
Is ascorbic acid fat soluble or water soluble?
Water soluble
Deficiency of which two water-soluble vitamins can cause macrocytic anemia?
Folate and Vit B12
Which water-soluble vitamin is associated with collagen synthesis?
Vitamin C (ascorbic acid)
Name two vitamins that serve as antioxidants.
Vitamin E and Vitamin C
Name the four fat-soluble vitamins.
ADEK
True or False? The absorption of fat-soluble vitamins depends on the pancreas as well as the gastrointestinal tract.
True; pancreatic lipases are necessary for absorption of fat-soluble vitamins
Is accumulation of fat- or water-soluble vitamins more likely to cause toxicity?
Fat
Name two malabsorption syndromes that can cause fat-soluble vitamin deficiencies.
Cystic fibrosis and sprue
Are the B-complex vitamins fat soluble or water soluble?
Water soluble
All of the water-soluble vitamins easily wash out from the body, except for which two?
Vitamin B12 and folate
In which organ is folate stored?
Liver
B-complex deficiencies often result in what three conditions?
Dermatitis, glossitis, and diarrhea
What is another name for vitamin A?
Retinol (remember Retinol is Vitamin-A, so think Retin-A)
What are the signs and symptoms of vitamin A deficiency?
Night blindness and dry skin
Vitamin A is a constituent of what visual pigment?
Retinal
What are the symptoms associated with vitamin A intoxication?
Arthralgias, fatigue, headaches, skin changes, sore throat, and alopecia
A man has recently been eating large amounts of liver. He presents with fatigue, hair loss, headache, and joint pains. What is your diagnosis?
Vitamin A excess
What foods contain high amounts of vitamin A?
Vitamin A is found in liver, and in leafy vegetables
Name two topical uses of vitamin A.
It can be used topically for wrinkles and for acne
What are the effects of taking large amounts of vitamin A during pregnancy?
It is a teratogen, and causes cleft palate and cardiac abnormalities
What is another name for vitamin B1?
Thiamine
Beriberi is caused by a deficiency of which vitamin?
Vitamin B1 (thiamine) (spell beriberi as Ber1Ber1)
Wernicke-Korsakoff syndrome is caused by a deficiency of which vitamin?
Vitamin B1 (thiamine)
Vitamin B1 is the precursor to what metabolic cofactor?
Thiamine pyrophosphate
What is the role of thiamine in the tricarboxylic acid cycle?
It is a cofactor for -ketoglutarate dehydrogenase
Which step in glycolysis requires thiamine?
Thiamine pyrophosphate is needed as a cofactor for pyruvate dehydrogenase
What vitamin is needed as a cofactor for branched-chain amino acid dehydrogenase?
Vitamin B1 (thiamine)
A known alcoholic presents with symptoms of muscle wasting and polyneuritis. What vitamin deficiency do you suspect?
Vitamin B1 (thiamine)
Are polyneuritis and muscle wasting characteristic of wet or dry beriberi?
Dry beriberi; wet beriberi is associated with high-output cardiac failure and edema
Why are alcoholics prone to beriberi and Wernicke-Korsakoff syndrome?
Malnutrition and malabsorption
An alcoholic patient in the emergency room has recent-onset ophthalmoplegia, confusion, and ataxia; you suspect what disease process?
Wernicke-Korsakoff syndrome
Why are the brain and heart susceptible to injury in thiamine deficiency?
Cells cannot generate adenosine triphosphate without thiamine and highly metabolically active cells are damaged first
What is another name for vitamin B2?
Riboflavin
Cheilosis and corneal vascularization occur as a result of a deficiency of which vitamin?
Vitamin B2(riboflavin) (remember: the 2 C;s)
What is cheilosis?
Inflammation of the lips, with scaling and fissures at the corners of the mouth; this is seen in vitamin B2 deficiency
Flavin adenine dinucleotide is derived from which vitamin?
Vitamin B2(riboflavin) (remember: FAD and FMN are derived from riboFlavin, B2 = 2ATP)
What is another name for vitamin B3?
Niacin
A deficiency of vitamin B3 (niacin) leads to what disease?
Pellagra
How can Hartnup disease lead to pellagra?
Through impaired absorption of tryptophan, which is used to synthesize niacin
How can malignant carcinoid syndrome lead to pellagra?
Through increased metabolism of tryptophan, which is used to synthesize niacin
How does isoniazid cause a niacin deficiency?
By depleting vitamin B6, the synthesis of niacin from tryptophan cannot occur
A patient being treated for hyperlipidemia complains of becoming red in the face after taking his medication; what drug is he taking?
He is likely on niacin, which at pharmacologic doses can cause facial flushing
What vitamin is the precursor of oxidized nicotinamide adenine dinucleotide and oxidized nicotinamide adenine dinucleotide phosphate?
Vitamin B3 (niacin) (remember: NAD derived from Niacin, B3 = 3 ATP)
What are the 3 D;s of pellagra?
Diarrhea, Dermatitis, and Dementia
True or False? In addition to diarrhea, dermatitis, and dementia, pellagra is also characterized by beefy glossitis.
True
True or False? Eating excess untreated corn can lead to pellagra.
True; vitamin B3 in corn is not absorbable unless treated
What is another name for vitamin B5?
Pantothenate
Pantothenate
Dermatitis, enteritis, alopecia, and adrenal insufficiency
What vitamin is a precursor of coenzyme A, a cofactor for acyl transfer?
Vitamin B5 (pantothenate) (remember: pantothen-A is in Co-A)
What vitamin is a component of fatty acid synthase?
Vitamin B5 (pantothenate)
Adrenal insufficiency may be caused by a deficiency of which vitamin?
Vitamin B5(pantothenate)
What is another name for vitamin B6?
Pyridoxine
What are the clinical features of vitamin B6 deficiency?
Convulsions, hyperirritability, peripheral neuropathy, and sideroblastic anemias
A deficiency of vitamin B6 is inducible by what two drugs?
Isoniazid and oral contraceptive pills
A 32-year-old man begins taking isoniazid after a positive purified protein derivative. He presents with numbness and tingling in the extremities. What is the most likely cause of his peripheral neuropathy?
Vitamin B6(pyridoxine) deficiency induced by INH
Which vitamin is the precursor to pyridoxal phosphate?
Vitamin B6 (pyridoxine)
Which vitamin is needed for transamination (alanine aminotransferase and aspartate aminotransferase) reactions?
Vitamin B6 (pyridoxine)