Water-Soluble Vitamins: B-Group and Vitamin C - Comprehensive Notes

Water-Soluble Vitamins: B-Group and Vitamin C

Overview

  • Water-soluble vitamins include the B-group vitamins and Vitamin C.
  • B-Group vitamins consist of 8 distinct vitamins essential for energy production.
  • They act as coenzymes in numerous biochemical reactions, facilitating energy extraction from carbohydrates, fats, and proteins.
  • Vitamin C (ascorbic acid) supports immune function and acts as an antioxidant.

B-Group Vitamins

  • Crucial for energy release from carbohydrates, fats, and proteins.
  • Includes:
    • Thiamine (B1)
    • Riboflavin (B2)
    • Niacin
    • Pantothenic acid
    • Biotin
    • Vitamin B6 (pyridoxine)
    • Folate
    • Vitamin B12
  • Vitamin B6 (pyridoxine) aids in amino acid metabolism.
  • Folate and Vitamin B12 support cell replication by creating new DNA, crucial for red blood cells and GI tract cells.

Thiamine (B1)

  • Active form: thiamine pyrophosphate (TTP).
  • Essential for the conversion of pyruvate to acetyl CoA.
  • Regulates ion channels.
  • Deficiency can lead to Wernicke-Korsakoff syndrome.
    • Prevalent in individuals with alcoholism.
    • Combines cerebral beriberi with psychosis.
  • Can also manifest as beriberi.
    • Wet beriberi: Affects the cardiovascular system.
    • Dry beriberi: Impacts the nervous system.
  • Food sources: meat and meat products, wholegrains, enriched breads and cereals, yeasts, and vegemite.

Riboflavin (B2)

  • Crucial for energy metabolism.
  • Acts as a precursor for two important coenzymes: Flavin mononucleotide (FMN) and Flavin adenine dinucleotide (FAD).
  • Helps protect cells from oxidative stress and damage.
  • Deficiency can lead to ariboflavinosis, characterized by sore throat, mouth ulcers, and skin disorders.

Niacin

  • Found in the forms of nicotinic acid and nicotinamide.
  • Crucial for energy metabolism and DNA synthesis.
  • Coenzyme forms: NAD and NADP, involved in over 200 metabolic reactions, highlighting its importance in cellular function.
  • Deficiency leads to the four D’s: Dermatitis, Diarrhea, Dementia, and Death.
  • Food sources: Milk, eggs, meat, poultry.

Pantothenic Acid (B5)

Pyridoxine (B6)

  • Deficiency symptoms include depression, confusion, and dermatitis.
  • Food sources: Meat, poultry, fish, potatoes, non-citrus fruits.

Biotin (B7)

  • Coenzyme for carboxylase enzymes, critical in the metabolism of carbohydrates, fats, and proteins.
  • Deficiency leads to skin rashes, hair loss, and neurological symptoms.