1. Fundamental Classification: Fat-Soluble vs Water-Soluble
Vitamins are organic compounds required in minute quantities for cellular metabolism. In 1912, Polish biochemist Casimir Funk coined the term "Vitamine" (vital amine). Vitamins are divided into two fundamental biochemical categories:
Fat-Soluble Vitamins (A, D, E, K)
- Stored in liver and adipose (fatty) tissue.
- Do not need to be consumed daily; excessive intake can lead to toxic accumulation (Hypervitaminosis).
- Mnemonic: "KEDA" or "ADEK" dissolves in fat/organic solvents.
Water-Soluble Vitamins (B-Complex & C)
- Not stored in the body in large quantities (except Vitamin B12 in the liver).
- Excess amounts are readily filtered by the kidneys and excreted in urine.
- Must be replenished regularly through diet; easily destroyed by prolonged boiling/cooking.
2. The Complete Vitamin Master Compendium
| Vitamin | Scientific / Chemical Name | Primary Dietary Sources | Deficiency Disorder & Key Symptoms |
|---|---|---|---|
| Vitamin A | Retinol / Beta-Carotene | Carrots, Papaya, Mango, Spinach, Cod liver oil | Nyctalopia (Night Blindness), Xerophthalmia (dry cornea), Bitot's spots on conjunctiva. |
| Vitamin B1 | Thiamine | Whole grains, yeast, unpolished brown rice | Beriberi (Dry: nerve damage/paralysis; Wet: heart failure/edema); Wernicke-Korsakoff syndrome. |
| Vitamin B2 | Riboflavin (Yellow enzyme) | Milk, eggs, liver, green vegetables | Cheilosis (cracking at corners of mouth), Glossitis (inflamed magenta tongue). |
| Vitamin B3 | Niacin / Nicotinic Acid | Peanuts, mushrooms, meat, legumes | Pellagra (Characterized by the 3 Ds: Dermatitis, Diarrhea, Dementia; if untreated, Death). |
| Vitamin B9 | Folic Acid / Folate | Green leafy vegetables, citrus fruits, lentils | Megaloblastic Anemia; Neural Tube Defects (Spina Bifida) in growing fetuses. |
| Vitamin B12 | Cyanocobalamin | Meat, fish, eggs, dairy (Absent in plant food) | Pernicious Anemia, severe irreversible neurological degeneration. Contains Cobalt metal ion. |
| Vitamin C | Ascorbic Acid (Heat-labile) | Amla (Indian gooseberry — richest), Citrus fruits, Guava | Scurvy (Bleeding and spongy gums, impaired collagen synthesis, delayed wound healing, loose teeth). |
| Vitamin D | Calciferol (Sunlight vitamin) | Sunlight (synthesized in skin from 7-dehydrocholesterol), Fish liver oil | Rickets in children (bow legs, pigeon chest); Osteomalacia in adults (soft, fragile bones). |
| Vitamin E | Tocopherol (Beauty vitamin) | Wheat germ oil, almonds, sunflower seeds | Antioxidant deficiency, hemolytic anemia, muscular dystrophy, reproductive failure / sterility in animals. |
| Vitamin K | Phylloquinone / Naphthoquinone | Cabbage, spinach, synthesized by gut flora (E. coli) | Defective blood coagulation / Hemorrhage (Required for liver synthesis of Prothrombin — Factor II, VII, IX, X). |
3. Crucial Mineral Deficiencies & Exam Traps
Iron (Fe):
Core element in Hemoglobin. Deficiency causes Microcytic Hypochromic Anemia (fatigue, pale conjunctiva, spoon nails / koilonychia).
Iodine (I):
Required for thyroid hormones (T3 and T4). Deficiency leads to Simple Goitre (enlarged thyroid) and Cretinism (mental/physical stunting in children).
Fluorine (F):
Trace amounts protect against tooth decay. However, excess (>1.5 ppm in groundwater) leads to Fluorosis (mottling of dental enamel and skeletal deformation).