Vitamin B1 and B2 Overview

Vitamin B1 (Thiamine)

• Thiamine is a sulfur-containing vitamin necessary for energy metabolism
• Sources include whole grains, legumes, and meats
• Alcohol inhibits thiamine absorption
• Deficiency can cause Wernicke encephalopathy, beriberi
  • Risk factors include alcohol dependency, malabsorption, and a diet low in thiamine
• Thiamine is stable in an acidic environment but decomposes readily above pH 5.0
• About 50% of thiamine in foods is destroyed during cooking

Vitamin B2 (Riboflavin)

• Riboflavin is a yellow, heat-stable substance
• Sensitive to light, decomposing into lumichrome or lumiflavin depending on the solution's pH
• Neither lumichrome nor lumiflavin has physiologic activity
• Main sources include yeast, dairy products, eggs, legumes, and meats
• Also found in cereal grains, fruits, and green vegetables
• Riboflavin is stable during cooking in the absence of light
• Riboflavin occurs in foods as the free form, FMN (Flavin mononucleotide), and FAD (flavin adenine dinucleotide)
• The nucleosides are hydrolyzed to riboflavin in the upper gastrointestinal tract
• Free riboflavin is readily absorbed by an active transport system enhanced by bile salts

Vitamin B3 (Niacin)

• Niacin refers to nicotinic acid and nicotinamide
• Niacin is found in most foods, particularly those rich in protein, such as meat, poultry, fish, eggs, nuts, and seeds
• Also found in whole grains, mushrooms, avocados, and some green leafy vegetables
• Nicotinic acid is the predominant form in animal tissues
• Pyridoxamine is the most stable

Vitamin B6 (Pyridoxine)

• Vitamin B6 is essential for biological reactions including amino acid metabolism, neurotransmitter synthesis, and red blood cell formation
• Key co-factor for diverse biochemical reactions regulating basic cellular metabolism
• Sources include beef liver, tuna, salmon, fortified cereals, chickpeas, poultry, and some vegetables and fruits
• Deficiency causes peripheral neuropathy
• Symptoms of deficiency resemble those of niacin and riboflavin deficiencies, including neurological abnormalities, skin lesions, and hypochromic microcytic anemia

Vitamin B7 (Biotin)

• Biotin plays a crucial role in metabolism as a coenzyme that transfers carbon dioxide
• Essential for the breakdown of food into energy
• Involved in many cellular reactions, particularly fat and protein metabolism of hair roots, fingernails, and skin
• Found in eggs, fish, meat, seeds, nuts, and certain vegetables
• Deficiency causes fatigue, depression, and dermatitis

Vitamin B9 (Folate)

• Folate, folacin, pteroylglutamic acid, and vitamin B9 are terms referring to a material with anemia properties
• Essential for brain development and function
• Aids in the production of DNA and RNA
• Important in the metabolism of vitamins and amino acids
• Crucial during early pregnancy to reduce the risk of birth defects of the brain and spine
• Required for the synthesis of glycine, methionine, nucleotides T & U
• Sources include beans, peanuts, sunflower seeds, fresh fruits, fruit juices, whole grains, and liver
• Deficiency can cause megaloblastic and macrocytic anemias, and glossitis

Vitamin B12 (Cobalamin)

• Vitamin B12 refers to a series of porphyrin-related corrinoid derivatives that prevent pernicious anemia
• Cyanocobalamin is the most stable form and is most frequently used in therapy
• Hydroxocobalamin is also used therapeutically
• Vitamin B12 acts as a coenzyme in the conversion of homocysteine to methionine
• Plays a role in the metabolism of fatty acids and amino acids
• Involved in the production of neurotransmitters
• Maintains the lining that surrounds and protects nerve fibers
• Crucial for bone cell activity
• Plays a significant role in DNA synthesis

Explore the essential roles of Vitamin B1 (Thiamine) and Vitamin B2 (Riboflavin) in energy metabolism and nutrition. Learn about their sources, absorption factors, and stability during cooking. Understand the risks of deficiency and the physiological activities of these vitamins.