Vitamins, Minerals & Human Nutrition
Human nutrition requires macronutrients (carbohydrates, proteins, lipids) and micronutrients (vitamins and minerals) to support metabolic functions and tissue repair. Vitamins are categorized into fat-soluble vitamins (A, D, E, K) and water-soluble vitamins (B-complex group and Vitamin C). Dietary deficiencies cause specific disorders: Vitamin A deficiency leads to xerophthalmia and night blindness; Vitamin B1 (thiamine) deficiency causes beriberi; Vitamin C (ascorbic acid) deficiency results in scurvy; and Vitamin D deficiency causes rickets in children and osteomalacia in adults. Essential dietary minerals include iron (required for hemoglobin synthesis; deficiency causes anemia), iodine (essential for thyroid hormone synthesis), and calcium for bone mineralization.
Key Concepts & Examination Highlights
- Fat-soluble vitamins (A, D, E, K) are stored in hepatic and adipose tissues, whereas water-soluble vitamins (B-complex and C) require regular dietary intake.
- Vitamin B12 (cobalamin) is the only vitamin containing a metallic cobalt ion, and its deficiency causes pernicious anemia.
- Iodine is essential for the synthesis of thyroxine ($T_4$) and triiodothyronine ($T_3$); severe iodine deficiency leads to endemic goiter.