MCQ MAHE 2000 Medicine Answer 08

Vitamin B6

• Pyridoxal, pyridoxine, pyridoxamine
• And associated phosphates
• Active coenzyme form is pyridoxal phosphate
  

Pyridoxal phosphate-dependent reactions

Protein--transamination, deamination
• Rate-limiting step in hemoglobin synthesis
• Homocysteine conversion to cysteine
• Carbohydrate-glycogenolysis and gluconeogenesis
• Neurotransmitter synthesis--serotonin, dopamine, norepinephrine
  

Vitamin B6 Deficiency

Rare on its own
• Microcytic hypochromic anemia
• Dermatitis
• Neurologic symptoms
  

DRI’s for B6

• RDA for men and women aged 19-50: 1.3 mg
• Men > 51 years: 1.7 mg
• Women > 51 years: 1.5 mg
• UL: 100 mg/day
  

Food sources of Vitamin B6

• Liver
• Oatmeal
• Bananas
• Fortified cereals
• Chickpeas
  

B6 Toxicity

• Neurologic damage at doses > 1 g/day
• No evidence that high doses of B6 are useful in PMS or carpal tunnel syndrome

Category: MAHE 2000 MCQs