Vitamins Flashcards
What is the Function of Vitamin A (retinol)
Where can we find Vitamin A?
vitamin A = antioxidant; for visual pigments and key in normal differentiation of epithelial cells to specialized tissue (pancreatic cells, mucus secreating cells);
Prevents squamous metaplasia (maintains orderly differentation of specilaize epithelia)
found in Liver and Leafy vegetables
Pc comes in with dry skin and loss of hair.
She has been having issues seeing at night.
What is the vitamin deficiency?
Vitamin A deficiency
Night blindness (nyctalopia); dry, scaly skin (xerosis cutis); corneal degeneration (keratomalacia); Bitot spots on conjunctiva; immunosuppression.
Woman taking this Vitam may end up with a baby that has cleft palate and cardiac anomalies.
Vitamin A or Retinol
Teratogenic (cleft palate, cardiac abnormalities), therefore a ⊝ pregnancy test and reliable contraception are required before isotretinoin (vitamin A derivative) is prescribed for severe acne.
In thiamine pyrophosphate (TPP), a cofactor for several dehydrogenase enzyme reactions:
What are they?
TTP = Vitamin B 1
Pyruvate dehydrogenase (links glycolysis to TCA cycle)
α-ketoglutarate dehydrogenase (TCA cycle to generate NADH)
Transketolase (HMP shunt)
Branched-chain ketoacid dehydrogenase
Think ATP: alpa-Ketoglutarate DH, Transketolase, Pyruvate Dehydrogenase
confusion, ophthalmoplegia, ataxia (classic triad) + confabulation, personality change, memory loss (permanent). Damage to medial dorsal nucleus of thalamus, mammillary bodies.
Vitamine deficiency?
Thiamine Deficineyc leading to Wernicke Korsacoff Syndrome
IN Werniki Korsacof we see LOW Thiamine (B1) which leads to :Impaired glucose breakdown?–> ATP depletion. When tx whats the worst thing we can do?
How do we diagnose pt with Vitamin B1 deficiency?
by glucose infusion; highly aerobic tissues (e.g., brain, heart) are affected first.
Diagnosis made by INCREAE ?in RBC transketolase activity f_ollowing vitamin B1 administration._
This vitamin is essential in Redox reactions, specifically used by Succinate Dehydrogenase in TCA cycle
Riboflavin or Vitamin B2 necessary to make FAD and FMN as cofactors in redox reactions
What vitamin is necessary to make FAD and FMN which are used by succinate DH in the TCA cycle?
Vitamin B2; riboflavin
What Vitamin is low in pt with chelosis and corneal abbrasions?
What reaction in the body would be affected as well?
Chelosis and Cornreal abrastion seen Riboflavin or Vit B2 defiicency
Need riboflavin to make FAD and FMN necessary for redox reactions
Which Vitamin plays a key role in Redox reactions?
It also relies on both vitamins B2 and B6 to make it?
Vitamin B3 or Niacin: key to making NAD and NADP+ for redox reactions and makes 3 ATP
Niacin is derived from what AA?
What can we use Niacin for?
Derived from tryptophan.
Used to treat dyslipidemia; lowers levels of VLDL and raises levels of HDL: causes rash
Pt presents with horrible diarrhea. They are disoriented to time and place.
On exam they have a very red tongue and dry skin.
What Vitamin are they deficient in?
Niacin or Vit B 3: the 3 D’s of Pellegra
Pt comes in with red beefy tongue and bad sores. You suspect Vit B3 deficiency. What inherited disorder can lead to this?
What is the pathophysiology?
Na+-dependent transporters in PCT reabsorb amino acids.
Hartnup disease—autosomal recessive. Deficiency of neutral amino acid (e.g., tryptophan)
transporters in proximal renal tubular cells and on enterocytes–>?neutral aminoaciduria and ?DECREASD absorption from the gut–>DECREASED ??tryptophan for conversion to niacin—>?pellagra-like symptoms.
Treat with high-protein diet and nicotinic acid.
How is malignant carcinoid sydrome linked with Vit B 3 deficiency?
Malignancy carcoinoid will increased metabolish of Tryptophan
Tryptophan in necessary for Vit B 3 or niacin production
How does Isoniazid lead to symptoms of Pellegra?
Isoniazid will decrease Vit B6
B6 is necessary to make Vit B1 (Niacin) along with B2 and Tryptophan
Thus see pellegra
This vitamin is an essential co-factor for Coenzyme A
What symptoms do we see if it’s missing?
Vitamin B 5 = Panthothenate
Low B5 = Dermatitis, Enteritis, Alopecia and Adrenal insufficiency
Pt comes to office with signs of adrenal insufficiency, hair thinning and abdominal cramping. What is the Vitamin deficiency?
What EnZ will be non-function withouth this ?
Vitamin B5 (Panthotene)
key for coenZ A (CoA a cofactor for acyl transfers) and fatty acid synthesis
sings Vit B 5 deficiency = dermatitis, enteritis, alopecia, adrenal insufficiency
Pt Comes to the office complaining of numbness and tingling on hands and feet. Have TB and started medications. Now experiencing sensory ataxia and decreased pain sensation in distal extremeties. What’s responsible?
Isoniazid simularly strutctual to vitamin B6 (pyridoxine) thus you have decrease of lots of neurotransmitters (GABB) and will increase excreation of Pryidoxine as well
Need pyridoxine supplementation when tx with Isoniazid