Essential Vitamins: Functions, Sources, and Deficiencies
Vitamin D (Calciferol): D2-D6, derived from ergosterol and cholesterol via UV catalysis. Found in shells and leaves. Regulates calcium, preventing rickets and osteomalacia. Excess can cause digestive disorders and visceral calcification.
Vitamin E (Tocopherol): Found in green vegetables, seeds, oils, and eggs. Important for fertility. Deficiency leads to infertility, paralysis, and muscular dystrophy. Excess can be toxic.
Vitamin K (Phylloquinone): K1-K4, found in green vegetables and fish. K3 produced by bacteria. Essential for blood coagulation and fibrinogen production in the liver. Deficiency causes hemorrhage.
Vitamin C (Ascorbic Acid): Found in citrus fruits, cinnamon, vegetables, and milk. A reducing agent involved in collagen synthesis. Deficiency causes scurvy, bleeding gums, tooth loss, digestive issues, and increased susceptibility to infections.
B Vitamins
Vitamin B1 (Thiamine): Found in bacteria, fungi, shell beans, cereals, legumes, pork, viscera, lean meats, and eggs. Regulates carbohydrate metabolism and catalyzes the synthesis of neural regulators. Deficiency causes beriberi, neuronal degeneration, muscle weakness, hypersensitivity, loss of reflexes and appetite, cardiac issues, edema, and cramps.
Vitamin B2 (Riboflavin): Found in bacteria, yeast, xanthophyll-rich vegetables, viscera, meat, milk, eggs, pasta, and bread. Part of FAD and FMN, coenzymes in oxidative processes. Maintains membrane integrity. Deficiency causes irritability, hypersensitivity, impaired mucous membranes, photophobia, and dermal lesions.
Vitamin B3 (Pantothenic Acid): Found in bacteria, yeast, green vegetables, cereals, beans, chickpeas, peas, liver, poultry, salmon, and tuna. Part of Coenzyme A, involved in fatty acid degradation and cholesterol oxidation. Deficiency causes dermatitis, skin discoloration, anemia, and growth retardation.
Vitamin B5 (Niacin): Found in yeast, milk, eggs, and meat. Synthesized from tryptophan in animals. Component of NAD and NADP. Deficiency causes pellagra, mental confusion, memory loss, hallucinations, and paranoia. Excess can cause skin aging, burning sensations, and itching.
Vitamin B6 (Pyridoxine): Found in whole grains, bread, avocado, spinach, banana, beans, and liver. Involved in amino acid absorption, metabolism, and erythropoiesis. Deficiency causes dermal alterations, cracked lips, a smooth tongue, seizures, dizziness, nausea, anemia, and fatigue.
Vitamin B7 (Biotin): Found in bacteria and plants. Involved in CO2 fixation, fatty acid synthesis, and carbohydrate oxidation. Deficiency causes scaly skin, paleness, muscle pain, and anemia.
Vitamin B9 (Folic Acid): Found in viscera, green leafy vegetables, dried fruits, grains, and brewer’s yeast. A coenzyme in protein formation and hemoglobin synthesis. Deficiency is rare due to liver storage but can cause problems with hemoglobin synthesis and anemia.
Vitamin B12 (Cobalamin): Contains a porphyrin ring with a cobalt atom. Found in bacteria. Involved in protein metabolism, nucleic acid synthesis, and erythropoiesis. Deficiency causes pernicious anemia and malformed red blood cells.
Vitamin A
Vitamin A (Antixerophthalmic): Found in yellow vegetables, with carotene as a precursor. Stored in the liver. Retinene is a precursor. Deficiency causes infections in mucosal epithelium, skin, and xerophthalmia. Excess can cause toxicity, choking, hair loss, and weakness.