Nutrients Module 3.1: Vitamin B1 and Energy Production

Study Notes

Vitamin B Complex and Energy Metabolism

Vitamin B1 (Thiamine):
- Biological active form: Thiamine Pyrophosphate (TPP)
- Involved in energy production and nutrient metabolism
- Required for the synthesis of acetyl choline, a neurotransmitter
- Plays a role in glycolysis, conversion of pyruvate to acetyl CoA, and the Krebs cycle
- Also involved in peroxisomal fatty acid degradation
Vitamin B2 (Riboflavin):
- Coenzyme forms: Flavin Mononucleotide (FMN) and Flavin Adenine Dinucleotide (FAD)
- Involved in energy metabolism and catalyzes redox reactions
- FAD-dependent enzymes: PDH, KGDH, Succinate dehydrogenase, and Kynurenine 3-Monooxygenase
Vitamin B3 (Niacin):
- Coenzyme forms: Nicotinamide Adenine Dinucleotide (NAD) and Nicotinamide Adenine Dinucleotide Phosphate (NADP)
- Involved in energy metabolism, glycolysis, and the citric acid cycle
Vitamin B5 (Pantothenic acid):
- Precursor to Coenzyme A (CoA)
- CoA is involved in energy metabolism, fatty acid synthesis, and the citric acid cycle
Vitamin B6 (Pyridoxine):
- Coenzyme form: Pyridoxal Phosphate (PLP)
- Involved in amino acid, glucose, and lipid metabolism
- Required for the synthesis of catecholamines, heme, and NAD
Vitamin B7 (Biotin):
- Coenzyme form: Biotin
- Involved in fatty acid synthesis, gluconeogenesis, and amino acid metabolism
Vitamin B9 (Folic acid):
- Coenzyme form: Tetrahydrofolate (THF)
- Involved in one-carbon metabolism, amino acid synthesis, and nucleotide synthesis
Vitamin B12 (Cyanocobalamine):
- Coenzyme form: Adenosylcobalamin
- Involved in the conversion of L-Methyl Malonyl CoA to Succinyl CoA

Vitamin A and Zinc

Vitamin A:
- Involved in the visual cycle, gene transcription, and cell differentiation
- Zinc is essential for the absorption and utilization of vitamin A
- Deficiency in vitamin A leads to impaired vision and immune function
Zinc:
- Involved in the absorption and utilization of vitamin A
- Plays a role in the normal functioning of the immune system
- Essential for the activity of many enzymes and proteins

Iron and Protein

Iron:
- Has two oxidation states: ferrous (Fe2+) and ferric (Fe3+)
- Essential for the function of many enzymes and proteins
- Involved in energy metabolism, particularly in the citric acid cycle
- Regulation of iron absorption is crucial to prevent toxicity
Protein:
- Involved in the transport of iron in the body
- Hepcidin, a protein produced in the liver, regulates iron absorption
- DMT1, a protein located on the surface of enterocytes, facilitates the uptake of iron

Interrelation between Fat and Vitamins A, D, E, and K

Vitamin A:
- Absorbed in the intestines with the help of bile salts
- Transported to the liver via chylomicrons
- Stored in the liver and adipose tissue
Vitamin D:
- Absorbed in the intestines with the help of bile salts
- Transported to the liver via chylomicrons
- Stored in the liver and adipose tissue
Vitamin E:
- Absorbed in the intestines with the help of bile salts
- Transported to the liver via chylomicrons
- Stored in the adipose tissue
Vitamin K:
- Absorbed in the intestines with the help of bile salts
- Transported to the liver via chylomicrons
- Stored in the liver and adipose tissue