Unit 1: Vitamins and Minerals

Table of Contents

Classification and Nomenclature of Vitamins

Vitamins are organic compounds required in tiny amounts for the normal growth, maintenance, and functioning of the body. They cannot be synthesized by the body (or in sufficient amounts) and must be obtained from the diet.

Nomenclature

Vitamins are named using capital letters (A, C, D, E, K) or by the B-complex system (B1, B2, B6, B12). Sometimes they are also referred to by their chemical names (e.g., Vitamin C is Ascorbic Acid, Vitamin B12 is Cyanocobalamin).

Classification

Vitamins are broadly classified based on their solubility:

  1. Fat-Soluble Vitamins:
    • Vitamins: A, D, E, and K.
    • Solubility: Soluble in fat and fat solvents.
    • Storage: They are stored in the body's fatty tissues and liver.
    • Toxicity: Because they are stored, excessive intake (hypervitaminosis) can lead to toxicity.
  2. Water-Soluble Vitamins:
    • Vitamins: B-complex vitamins (B1, B2, B3, B5, B6, B7, B9, B12) and Vitamin C.
    • Solubility: Soluble in water.
    • Storage: They are *not* stored in the body in significant amounts (except B12).
    • Toxicity: Excess is usually excreted in urine, so toxicity is rare.

Need and Types of Vitamins

Need for Vitamin in Body

Vitamins are essential for life and perform numerous critical functions:

  • Coenzymes: Many B-vitamins act as coenzymes, which are "helper molecules" necessary for enzymes (biological catalysts) to function.
  • Regulation: They regulate metabolic processes, cell growth, and development.
  • Antioxidants: Vitamins C and E act as antioxidants, protecting cells from damage caused by free radicals.
  • Vision: Vitamin A is essential for vision.
  • Bone Health: Vitamin D is required for calcium absorption and bone formation.
  • Blood Clotting: Vitamin K is essential for the blood clotting cascade.

Detailed Vitamin Profiles

The syllabus requires a specific focus on the following vitamins:

Summary of Key Vitamins
Vitamin Type Sources Deficiency Disease(s)
Vitamin A1 (Retinol) Fat-Soluble Fish liver oils, dairy products, eggs, carrots, leafy greens (as beta-carotene). Night blindness, Xerophthalmia (dry eyes), impaired immunity.
Vitamin B12 (Cyanocobalamin) Water-Soluble Meat, fish, eggs, dairy products (not found in plants). Pernicious anemia (a type of megaloblastic anemia), nerve damage.
Vitamin C (Ascorbic Acid) Water-Soluble Citrus fruits (oranges, lemons), strawberries, broccoli, bell peppers. Scurvy (bleeding gums, weak connective tissue, poor wound healing).
Vitamin D (Calciferol) Fat-Soluble Sunlight (UVB on skin), fortified milk, fatty fish, egg yolks. Rickets (bone softening) in children, Osteomalacia in adults.
Vitamin E (Tocopherol) Vegetable oils, nuts, seeds, leafy greens. Rare in humans; can cause nerve and muscle damage, hemolytic anemia.
Vitamin K (Phylloquinone) Green leafy vegetables (spinach, kale), synthesized by gut bacteria. Impaired blood clotting, leading to excessive bleeding.

Role of Minerals

Minerals are inorganic elements required by the body for various functions. They can be macrominerals (needed in larger amounts, e.g., Ca, P, K, Na, Mg) or trace minerals (needed in tiny amounts, e.g., Fe, Zn, I, Se).

Role of Minerals in Body

  • Bone and Teeth: Calcium and Phosphorus form the hard matrix of bones and teeth.
  • Fluid Balance: Sodium and Potassium are key electrolytes in maintaining fluid balance and nerve function.
  • Oxygen Transport: Iron is the central component of hemoglobin, which carries oxygen in the blood.
  • Enzyme Cofactors: Many minerals (like Zn, Mg, Mn) act as cofactors for hundreds of enzymes.
  • Thyroid Function: Iodine is essential for the synthesis of thyroid hormones.

Iodine Deficiency and Remedy

  • Role of Iodine: Iodine is a trace element that is absolutely essential for the thyroid gland to produce thyroid hormones (thyroxine T4 and triiodothyronine T3).
  • Function of Thyroid Hormones: These hormones regulate the body's metabolism, body temperature, growth, and brain development.
  • Deficiency: When iodine intake is low, the thyroid gland cannot produce enough hormones. The pituitary gland signals the thyroid to work harder, causing it to enlarge.
    • Goiter: A visible swelling of the thyroid gland in the neck.
    • Cretinism: Severe iodine deficiency during pregnancy can lead to stunted physical and mental growth in the child.
    • Hypothyroidism: Slowed metabolism, weight gain, fatigue.
  • Remedy: The most common and effective remedy is the fortification of table salt with iodine (iodized salt). Eating seafood and dairy products also provide iodine.