Vitamins Flashcards
VThere are (number) vitamins B.
8 Vitamins B.
B1, B2, B3, B5, B6, B7, B9, B12
All vitamins B are WATER insoluble.
FALSE
They are soluble.
Most of vitamins B are few storage because of their chcaracteristics of being water SOLUBLE.
True
Exception is B12: stored in liver (mainly), also muscles
Commom symptoms of Vitamins B deficiencies:
Dermatitis (skin);
Glossitis (swelling/redness of tongue);
Diarrhea (GI tract);
Cheilitis (skin breakdown at corners of lips);
Thiamine Deficiency - BERIBERI - Dry and Wet type symptons:
Dry types: polyneuritis, muscle weakness;
Wet type: tachycardia, high-output heart failure, edema;
Wernucke-Korsakoff syndrome - symptons:
Alcoholics - malnourished;
Confusion, confabulation;
Ataxia
Ophthalmoplegia (blurry vision);
Malnourished patients/Alcoholics - if glucose is given first without thiamina - the organism is unable to metabolize glucose.
TRUE
Case reports of worsening Wernicke-Korsakoff.
Thiamine is vitamin b*
b1
Riboflavin is vitamin B2
True
The riboflavin is important in Electron Transport chain.
True
Riboflavin deficiency is very rare; Symptons:
Dermatitis, glossitis, Cheilitis, Corneal vascularization;
Niacin can be synthesized from tryptophan.
True
Conversion of trypthophan in Niacin requires vit B6.
Niacin- Vitamin B3 is used in electron transport.
True
Deficiency of niacin is known as Pellagra.
True
Four D’s of Pellagra:
Dermatitis
Diarrhea
Dementia
Death
Isoniazid (inh therapy) - used in tuberculosis - decreases B6 activity that will decrease Niacin levels (from tryptophan).
True
Hartnup Disease represents the absence of… … and it’s a autosomal recessive.
AA transporter in proximal tuble
Hartnup Disease represents loss of tryptophan in urine.
true
Less trypthophan consequency is less synthesis of niacin.
TRUE
The pacient will develop symptons from niacin deficiency.
Pacients with carcinoide Syndrome can have altered tryptophan metabolism and develops deficiency of this aminoacid;
As consequence of that: Pellagra.
Niacin B3 is also used to treat hyperlipidemia.
Yes
Niacin Excess causes:
Facial flushing
Cause of niacin excess:
Seen with niacin treatment for hyperlipidemia.
Vitamin B5 is Pantothenic acid wich most important activity is…
Doing coenzyme A
B5 deficiency is very rare
True
Symptons of Pantithenic acid deficiency:
GI symptoms: nausea, vomiting, cramps
Numbness, paresthesias (burning feet);
Necrosis of adrenal glands seen in animal studies;
Vitamin b6 has three compounds:
Pyridoxine - plants
Pyridoxal, Pyridoxamine (animals)
All vit b6 are converted to pyridoxal phosphate;
true
Pyrydoxal phosphate plays a role in the pathways for synthesizing…
Dopamine
Noreponephrine
Epinephrine
Serotonin
GABA
Deficiency of B6 can cause Sideroblastic anemia;
True
What ocurr in in sideroblastic anemia?
Iron cannot be incorporated into HEME
Iron acumulates in RBC cytoplasm;
Lead poisoning can cause sideroblastic anemia by interfering conversion of ALA into HEME;
True
Isoniazid (tuberculosis drug) is similar to B6 structure.
True
As result of that forms inactive pyridoxal phosphate.
Isoniazid results in relative B6 deficiency
True
Isoniazid users must supplement … when taking INH.
B6
Oral contraceptives can increase vitamin b6 requirements.
True
Vitamin B6 deficiency symptoms are…
CNS symptoms
- Seizures
- Confusion
- Neuropathy
Vitamin B6 toxicity can cause…
Pain/numbness in legs;
Sometimes difficulty walking;
Biotin - vitamin 7
Cofactor for carboxylation enzymes
Importants enzymes to USMLE wich depends of Biotin:
Pyruvate carboxulase;
Acetyl coA carboxylase;
Propionyl-CoA carboxylase
ABC Enzymes depends of…
ATP
BIOTIN
CO2
Deficiency of Biotin is very rare
True
Symptoms of biotin deficiency:
Dermatitis, Glossitis, loss of appetite, nausea
Massive consumption of raw egg whites can cause biotin deficieny because of Avidin
True
B vitmamins are all absorbed from diet in…
Small intestine, most in jejunum
Exception is B12 in terminal Ileum
Vitamin B6 is a cofactor in a number of metabolic processes including synthesis of neurotransmitters, cystathionine, and heme.
true
