Water Soluble Vitamins Lecture Notes PDF

Water soluble vitamins Dr. Salah Omar December 10, 2024 www.gmu.ac.ae College of Health Learning objectives: List the water-soluble vitamins Classify the B vitamins as energy releasing or hematopoietic or both Name and des...

Water soluble vitamins Dr. Salah Omar December 10, 2024 www.gmu.ac.ae College of Health Learning objectives: List the water-soluble vitamins Classify the B vitamins as energy releasing or hematopoietic or both Name and describe the role of the coenzyme form of each B Vitamin Explain the role Vitamin C in the body List the diseases associated with deficiency of the water-soluble vitamins  B Vitamins can be divided into: Energy releasing: Thiamin, Riboflavin, Niacin, Pantothenic acid & Biotin. Hematopoetic: Folic Acid and B12.  Thiamine (B1)  Coenzyme form is Thiamine pyrophosphate (TPP).  Main role of TPP is in carbohydrate metabolism.  Also Required for transmission of nerve impulse. Sources of Thiamin Whole grains, yeast, seeds, vegetables, egg and milk Thiamin is destroyed by excessive cooking. Early symptoms : Irritability, depression, fatigue, peripheral neuropathy, anorexia, dyspepsia and weight loss. Severe thiamine deficiency results in two major diseases 1.Beri-beri 2.Wernicke-Korsakoff syndrome (seen commonly in alcoholics)  Riboflavin (B2) Coenzyme forms: FMN (Flavin MonoNucleotide) FAD (Flavin AdenineDinucleotide FAD and FMN: Participate in Oxidation- reduction reactions Examples 1. Coenzyme in Fatty acid oxidation. 2. TCA cycle  Food sources of Riboflavin: · Excellent source: Milk Good sources : Mushrooms, leafy green vegetables, meat, eggs, yeast and liver. · UV light destroys riboflavin. If Milk is exposed to sunlight 70% of riboflavin is inactivated. Deficiency 1. Glossitis: Inflammation of tongue. 2. Cheilosis: Swollen, cracked bright red lips. 3. Angular Stomatitis: Inflammation at the corners of mouth.  Niacin (B3) Nicotinic acid and Niacinamide. Coenzyme forms: NAD+ & NADP+ They are coenzymes for oxidoreductases (Hydrogen acceptors and donors). They play very important roles in almost all metabolic pathways: Glycolysis TCA cycle ETC Cholesterol metabolism Fatty acid oxidation and synthesis Niacin be synthesized from the amino acid tryptophan. Food sources · Yeast, fish, poultry, meats (high protein foods), liver. Deficiency disease- Pellagra (3Ds) Diarrhea Dermatitis ( Inflammation of skin) Dementia ( memory loss, disorientation, personality changes).  Pyridoxine (Vitamin B6) Pyridoxal phosphate (PLP) is the coenzyme form Required for a. Amino acid metabolism b. Neurotransmitter synthesis c. Heme synthesis Deficiency 1. Neurological Symptoms: 2. Anemia Other B vitamins 1. Pantothenic acid- Coenzyme form is Coenzyme A ( CoA-SH) Pantothenic acid is an important coenzyme in metabolic pathways 2. Biotin -Coenzyme form: Biotinyllysine, involved in carboxylation  Folic acid Coenzyme form is tetrahydrofolate ( THFA or FH 4) General functions of folic acid: 1. DNA synthesis and cell division ( prevents anemia). 2. Prevents neural tube defects in the fetus such as Spina bifida and anencephaly  Food sources · Legumes and green leafy vegetables are excellent sources. · Oranges and orange juice are good sources. RDA: 200 µg/day Increased need in pregnancy and lactation (400 ug/day) · Folate supplementation is done routinely during pregnancy and in many countries to all women of child bearing age.  B12 (Cobalamins) · Coenzyme forms: Methylcobalamin and deoxyadenosyl cobalamin (Ado B12). Absorption in the GIT requires Intrinsic factor (a protein secreted by the parietal cells of the stomach). Though water-soluble it can be stored in the liver Only animal products ( liver, fish, egg, meat, milk and yoghurt) supply B12. Vegans (who don’t eat animal products) can have difficulty in meeting their B12 requirements.  Deficiency · Megaloblastic anemia · Pernicious anemia: due to the lack of intrinsic factor. B12 must be injected. · Combined degeneration ( demyelination and neuronal death seen): unsteadiness in gait, memory loss, confusion etc  Ascorbic acid (Vitamin C) 1. Role in Collagen Formation Normal collagen formation is necessary for connective tissue maintenance, wound healing and bone formation. 2. Increases iron absorption by reducing the ferric state to ferrous in the stomach. 3. Antioxidant Vitamin C protects other compounds from oxidation by donating electrons. Deficiency disease is Scurvy Bleeding gums & Loose teeth. Hemorrhages & anemia. Poor wound healing Osteoporosis & easy bone fractures (abnormal osteoid formation). (Collagen is abnormal so capillaries are fragile leading to the tendency to bleed even under minor pressures). Food sources: · Citrus fruits (Lime, orange), strawberries, bell peppers and green leafy vegetables. · Vitamin C is unstable and can be destroyed by heating, oxygen and light.