Vitamins Classification: Fat Soluble Vitamins

Classification of Vitamins

• Vitamins are classified into two categories: Fat Soluble Vitamins and Water Soluble Vitamins

Fat Soluble Vitamins

• Vitamin A is derived from plant carotenoids and has three active forms: Retinol, Retinal, and Retinoic acid
• Vitamin A is essential for the synthesis of glycoproteins, regulation of cell growth, and iron transport protein transferrin synthesis
• Deficiency of vitamin A leads to drying of epithelial tissues, hyperkeratosis, and anemia
• Vitamin D synthesis requires sunlight exposure
• Vitamin D deficiency leads to nutritional rickets (in children) and osteomalacia (in adults)
• Vitamin E is a naturally occurring antioxidant that refers to a family of 8 related compounds, with Tocopherol being the most active
• Vitamin E is essential for stabilizing ATP production, preventing atherosclerosis, and maintaining normal immune function
• Deficiency of vitamin E leads to neurological symptoms and increased susceptibility to infection and cancer
• Vitamin K is a Quinone derivative that helps in blood clotting and bone metabolism
• Deficiency of vitamin K leads to hypoprothrombinemia and hemorrhagic disease in newborns

Water Soluble Vitamins

• Water soluble vitamins are excreted once their concentration is high, making toxicities rare
• Deficiencies of water soluble vitamins occur relatively quickly on an inadequate diet
• Water soluble vitamins are converted to coenzymes used in pathways for energy generation or hematopoiesis

Folic Acid

• Folic acid deficiency can occur due to poor diet, chronic alcoholism, inadequate absorption, or increased demand during pregnancy or lactation
• Folic acid deficiency leads to megaloblastic anemia, characterized by weakness, tiredness, irritability, and headache
• Deficiency symptoms of folic acid include anemia, smooth red tongue, mental confusion, weakness, fatigue, and irritability
• Toxicity symptoms of folic acid include masking vitamin B12 deficiency symptoms and an increased risk of neural tube defects

Vitamin B12 (Cobalamin)

• Vitamin B12 is required for two reactions: conversion of methylmalonyl-CoA to succinyl-CoA and the methionine synthase reaction
• Deficiency symptoms of vitamin B12 include pernicious anemia, megaloblastic anemia, and neuropathy
• Deficiency of vitamin B12 leads to accumulation of methylmalonyl-CoA, which causes neuropathy

Other Water Soluble Vitamins

• Vitamin C (Ascorbic Acid) is a cofactor for mixed function oxidases involved in the hydroxylation of lysine and proline

• Deficiency of vitamin C leads to scurvy, characterized by bleeding gums, swelling joints, and impaired wound healing

• Vitamin C is required for normal leukocyte function and histamine level decrease, making it recommended for the prevention of cold

• Pyridoxine (Vitamin B6) is a coenzyme for transamination, deamination, decarboxylation, and condensation reactions

• Deficiency of pyridoxine leads to poor activity of PLP-dependent enzymes, causing deficient amino acid metabolism, lipid metabolism, and neurotransmitter synthesis

• Deficiency symptoms of pyridoxine include irritability, nervousness, depression, peripheral neuropathy, and convulsions

• Biotin (Vitamin B7) is part of a coenzyme used in energy metabolism, fat synthesis, amino acid metabolism, and glycogen synthesis

• Deficiency symptoms of biotin include depression, lethargy, hallucinations, numb or tingling sensation in the arms and legs, and hair loss

• Pantothenic Acid (Vitamin B5) is part of coenzyme A, used in energy metabolism

• Deficiency symptoms of pantothenic acid include vomiting, nausea, stomach cramps, insomnia, fatigue, depression, and irritability