Podcast
Questions and Answers
What is the primary function of TPP in the body?
What is the primary function of TPP in the body?
Which of the following is a common source of thiamine?
Which of the following is a common source of thiamine?
What is the primary cause of beriberi in south Asia?
What is the primary cause of beriberi in south Asia?
What is the characteristic feature of wet beriberi?
What is the characteristic feature of wet beriberi?
Signup and view all the answers
What is the diagnostic test for thiamine deficiency?
What is the diagnostic test for thiamine deficiency?
Signup and view all the answers
What is the recommended treatment for thiamine deficiency?
What is the recommended treatment for thiamine deficiency?
Signup and view all the answers
What is the effect of thiamine deficiency on the cardiovascular system?
What is the effect of thiamine deficiency on the cardiovascular system?
Signup and view all the answers
What is the common manifestation of dry beriberi?
What is the common manifestation of dry beriberi?
Signup and view all the answers
Why is thiamine deficiency seen in cancer patients?
Why is thiamine deficiency seen in cancer patients?
Signup and view all the answers
What is the effect of thiamine treatment on oedema in wet beriberi?
What is the effect of thiamine treatment on oedema in wet beriberi?
Signup and view all the answers
Study Notes
Niacin (Vitamin B3)
- Synthesis: Can be synthesized in humans from tryptophane, with the presence of vitamin B6
- Food sources: Found in plants, meat, and fish; lost when bran is removed from cereals, but added to processed cereals and white bread
- Importance: Essential in many oxidative processes in the body, particularly in NAD and NADP
Pellagra
- Definition: A rare disease caused by niacin deficiency
- Causes:
- Maize eating population due to maize's deficiency in nicotinic acid and tryptophan
- Hartnup's disease, a rare inborn error of metabolism
- Generalized malabsorption
- Very low protein diet in renal or liver disease
- Carcinoid syndrome and pheochromocytoma, which divert tryptophane metabolism away from nicotinamide formation
- INH therapy, which can lead to vitamin B6 deficiency
- Clinical features:
- Dermatitis, often symmetrical, affecting sun-exposed areas, with redness, cracks, and occasional ulceration
- Diarrhea, with possible constipation, and gastrointestinal manifestations (painful red tongue, glossitis, angular stomatitis, achlorhydria)
- Dementia, with depression, apathy, and thinking disorders in mild cases, and tremors, encephalopathy, and acute psychosis in severe cases
- Diagnosis: Based on clinical features, with laboratory tests for RBC NAD levels
- Treatment:
- Nicotinamide 100 mg every 6 hours orally
- Protein-rich diet
- Treatment of underlying conditions
Riboflavin (Vitamin B2)
- Sources: Widely distributed in plants and animal cells, with good sources including dairy products and leafy vegetables
- Function: Cofactor for many oxidative reactions in cells
- Deficiency:
- Angular stomatitis or cheilosis (fissuring of the corners of the tongue)
- Glossitis (red, inflamed tongue)
- Seborrhoeic dermatitis (particularly in the face)
- Conjunctivitis with vascularization of the cornea and lens opacities
- Treatment: Riboflavin 5 mg TDS daily, usually given as part of vitamin B complex
Thiamine (Vitamin B1)
- Function: Important cofactor in CHO metabolism, oxidation of acetyl-CoA in the mitochondria, Kreb's cycle, and HMP shunt
- Sources: Found in cereals, grains, beans, nuts, and duck
- Deficiency:
- Beriberi
- Seen in starved patients, particularly those with cancer, and those with severe hyperemesis, especially when treated with fluids only
- Types of Beriberi:
- Dry Beriberi: Polyneuropathy and encephalopathy
- Wet Beriberi: Oedema in the legs, extending to involve the whole body, with ascites and pleural effusion, due to accumulation of lactic and pyruvic acid
- Cardiomyopathy and subsequent heart failure, with a high-output state
- Diagnosis:
- Suspected in endemic areas
- Treatment with thiamine and rapid disappearance of oedema is diagnostic
- Confirmed by measurement of transketolase activity in RBCs
- Elevated plasma pyruvate and lactic acids in acute forms of thiamin deficiency
- Treatment: Thiamine 50 mg IM for 3 days, followed by 10 mg TDS daily by mouth
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about the classic symptoms of Pellagra, including dermatitis, diarrhea, and dementia, and understand its connection to nicotinamide synthesis from tryptophan.