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.
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 following 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
This vitamin is involved in transanimation and decarboxylation steps in amino acid metabolism as well as heme and neurotransmitter synthesis.
It is often used to treate sideroblastic anemia and hyperhomocyteinemia
Pryridoxine or Vit B 6
Vitamin that is converted to pyridoxl phosphate which is a cofactor needed for transanimation (ALT and AST), decarboxylation reactions and glycogen phosphorylase
Pyridoxine (vit B 6)
Branched chain alpha ketoacid dehydrogenase, Pyruvate dehydrogenase and alpha detoglutarate dehydrogenase all requuire what coenZ to be functional
Tender Loving Care For Nancy
CoenZ A (B5)
Deficiency in this vitamin can lead to convulsions, hyperiiritabliity, peripheral neuropathy (of induced by isoniazid and oral contraceptives), and siderblastic anemia
Vit B 6 (pryidoxine)
This Vitamin is key in Carboxyaltion enZ that add 1 C
Pyruvate carboxylase: Pyruvate --> Oxaloacetate
Acetly CoA carboxylase: Acetyly CoA--> malonyl CoA
Propionyl CoA carboxylase: propionyl CoA--> Methymalonyl CoA
Vitamin B 6 or Biotin
(Aviding in egg whites binds Biotin avidly)
Person has thinning hair, dermatitis adn horrible stomach pain. He is a heavy weight lifter and has been on a high protein, low fat diet.
You suspect he's haveing trouble carboxylating shit.
What's the deficiency?
vit B7 or biotin
This vitamin is key for synthesis of RNA and DNA nitrogen bases as it is part of a coenZ that does transfer/methlyation
Where is this vitamin found?
Vitamin B9 (folate)
Found in leafy green vegetables. Absorbed in jejunum. Folate from foliage.
What is the role of Vitamin B 9?
Where can we get it in our diet?
it's Folic acid: converted to tetrahydrofolate; a coenZ for 1 carbon transfer/methylaiton reactions: need THF to make nitrogenous bases in DNA and RNA
found in leafy green veggies and absorbed in jejunum
What affect will a deficiency in folate have on our blood?
Vit B 9 or Folate deficiency-->
Macrocytic, Megaloblatic anemia; hypersegmented PMNS
also see glossitis but NO NO neuro symptoms
Patient comes to office complaining of fatigue. She doesn't smoke, doesn't drink and is sexually active with partner of 1 yr. She is not on any drugs . You notice palor and get a blood sample:
She has Macrocytic, Megaloblastic anemia with hypersegmented PMNs
Urine sample shows: Elevated homocystein, elevated hcG and normal Methylmalonic acid
Pt has Folate deficiency anemia
secondary to pregnancy
Hints: Megaloblatsic anemia with HIGH homocyctein and normal methymalonic acid
What are common causes of Folate deficiency anemia
What will you see on peripheral blood smear?
What will you see on labs?
Causes: Pregnancy, alcohol, drugs (phenytoin, sulfonamides, MTX)
blood: Macrocytic, Megaloblastic anemia with hypersegm PMNs
Labs: Elevated homocysteine, Normal methymalonic acid
Vitamin is a cofactor for Homocystein Methlytrasnferase (transfers CH3 groups) and
for Methylmalonyl-CoA mutase
Vitamin B12 (cobalamin)
Where do we get Vit B 12 (cobalamin)?
HOw would we get a vit B12 deficiency?
Found in animal products.: Synthesized only by microorganisms. Very large reserve pool (several years) stored primarily in the liver. Deficiency is usually caused by insufficient intake (e.g., veganism), malabsorption (e.g., sprue, enteritis, Diphyllobothrium latum), lack of intrinsic factor (pernicious anemia, gastric bypass surgery), or absence of terminal ileum (Crohn disease).
Pt comes in with signs of anemia. Peripheral blood smear shows Macrocytic anemia, megaloblastic anemia and hypersegmented PMNs
What could be the cause?
How would you make a definitive dx?
Vit B9 (folate) or Vit B12 (cobalamin) deficiency
both have INCREASED homocystein levels
Vit B12 has INCREASED Methylmalonic acid levels as well while V9 has normal levels
Pt comes in with macrocytic hypersegmented megaloblatic anemia. States they've had issues with balance and weakness in his arms and legs. What vitamin defieincy is responsible?
What will his labs look like?
Vit B12 (cobalamin) deficiency
See INCREASED homocystein levels and INCREASED methlymalonic acid levels
causes paresthetias by degeneration of Dorsal columns (fine touch of arms and legs), Lateral corticospinal tracts (movement) and spinocerebellar (balance)
Pt comes in with signs of scurvy. Why does this vitamin deficiency result in bleeding?
Vitamin C deficiency causes sCurvy due to a Collagen synthesis defect.
Necessary for hydroxylation of proline and lysine in collagen synthesis.
What is the role of Acrobic acid in the immune system?
What about Iron absorbption?
Where can we find it?
Ascorbic acid (Vit C) acts as antioxidant
Facilitates Fe absorption by reducing it to Fe+2 state
found in fruits and vegetables
What NT is affected by a pt that comes in with easy bruising, anemia, poor wound healing and corkscrew hair?
Vit C deficiency:
Dopamine B-hydroxylase needs this to convert dopamine--> NE
This vitamin increases absorption of Ca+ and bone mineralization.
What form is it found in in plants?
What about in milk?
What form is it stored in?
D2 = ergocalciferol; ingested form plants
D3 = cholecalcifrol--consumed in milk and from sun skin
25-OHD3 is storage form
1,25 (OH)2 D3 is calcitriol or the active form
What are signs and diseaes seen from Vit D defeiciency?
Adults: Osteomalacia with bone pain and musl weakness and hypocalcemia tetany
Children: rickets; bone pain and deformity
*Breast fed infants need oral vit D supplements
Pt comes in with Hypercalcemia, Hypercalciruria, loss of appetite and very lethargic. What disease could this person have?
Sign of Vit D excess:
Sarcoidosis: epitheliod macrophages will convert to active Vit D
What is the Vitamin that protects erythrocyte and membranes from free radical damage and may ENHANCE the anticoagulation effects of Warfarin
Vitamin E or Tocopherol
Pt comes in feeling weak and has an ataxic gait. You suscpet a vitamin deficiency. Below is the peripheral blood smear. What is the deficiency?
Vitamin E (tocopherol/tocotrienol) :
Hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract demyelination.
Both Vit E and VitB12 present with neurologic symptoms and anemia. How do we tell them apart?
Vit B12: Megaloblastic anemia with increases homocystein and increased methylmalonic
Vit E: Acanthocytosis of cells
Where do we aquire Vit K?
What reaction in body is it necessary for?
What factors in coagulation do we need it for?
Cofactor for the γ-carboxylation of glutamic acid residues on various proteins required for blood clotting. Synthesized by intestinal flora.
diSCo in 1972
Neonatal hemorrhage with Increased ?PT and? IINCREASED aPTT but normal bleeding time
What vitamin deficiency is implicated? What can we do to prevent this?
Vit K deficiency; neonates can't make Vit K yet bc have uncolonized gut
(may see this after prolongued antibiotic use as well)
Not in breast milk; neonates are given vitamin K injection at birth to prevent hemorrhagic disease of the newborn
Delayed wound healing, hypogonadism,?adult hair (axillary, facial, pubic), dysgeusia, anosmia, acrodermatitis enteropathica: May predispose to alcoholic cirrhosis.
Mineral essential for the activity of 100+ enzymes. Important in the formation of zinc fingers (transcription factor motif).
Baby comes to office with scales around its butt full of vesicular and pustular lesions without central clearing.
What is the vit deficiency?
What other features would we see?
Zinc defieincy: see impaired wound healing and these lesions around body orifices
Hypogonadism and azoospermia
hair loss and impaired taste and night blindness