Vitamins | Classification of Vitamins | Functions of Vitamins | Dietary Sources of Vitamins | Fats and Fatty Acids | Daily Requirements of Fats and Vitamins |

 


Vitamins: Overview, Classification, Functions, and Sources

Introduction

Vitamins are organic compounds essential for normal growth, development, metabolism, and overall health. They do not provide calories but are crucial in various physiological processes. Since the body cannot synthesize most vitamins, they must be obtained from the diet.

Classification of Vitamins

  1. Fat-Soluble Vitamins

    • Vitamins: A, D, E, and K
    • Storage: Stored in the liver and adipose tissue.
    • Absorption: Requires dietary fat for proper absorption.
    • Functions:
      • Vitamin A: Vision, immune function, and skin health.
      • Vitamin D: Bone health and calcium-phosphorus metabolism.
      • Vitamin E: Antioxidant, protects cell membranes.
      • Vitamin K: Blood clotting and bone metabolism.

  2. Water-Soluble Vitamins

    • Vitamins: B-complex (B1, B2, B3, B5, B6, B7, B9, B12) and Vitamin C
    • Storage: Not stored in the body; excess excreted in urine.
    • Functions:
      • B-Complex: Energy metabolism, red blood cell production, and nerve function.
      • Vitamin C: Collagen synthesis, immune support, and iron absorption.

Caloric Value of Vitamins

  • Vitamins themselves do not provide calories. However, they are crucial in metabolic pathways that convert macronutrients (carbohydrates, proteins, and fats) into energy.

Functions of Vitamins

VitaminFunctions
Vitamin AVision, growth, immune response, and reproduction.
Vitamin DEnhances calcium and phosphorus absorption, bone strength, and immune health.
Vitamin EAntioxidant properties, protects cells from oxidative damage.
Vitamin KBlood coagulation and bone health.
B-ComplexEnergy production, nerve function, and DNA synthesis.
Vitamin CAntioxidant, tissue repair, and immune enhancement.

Dietary Sources of Vitamins

VitaminDietary Sources
Vitamin ACarrots, sweet potatoes, spinach, liver, and dairy products.
Vitamin DSunlight, fatty fish (salmon, mackerel), fortified milk, and egg yolks.
Vitamin ENuts, seeds, vegetable oils, and green leafy vegetables.
Vitamin KKale, broccoli, spinach, and fermented foods.
B-ComplexWhole grains, meats, eggs, dairy, legumes, and green leafy vegetables.
Vitamin CCitrus fruits, strawberries, bell peppers, and tomatoes.

Fats and Fatty Acids

  1. Types of Fats

    • Saturated Fats: Found in animal products like butter and cheese.
    • Unsaturated Fats: Found in plant oils, nuts, and seeds. Includes monounsaturated and polyunsaturated fats.
    • Trans Fats: Artificial fats found in processed foods, detrimental to health.

  2. Fatty Acids

    • Essential Fatty Acids (EFAs): Omega-3 and Omega-6, vital for brain function and inflammation control.
    • Sources of EFAs: Fish (salmon, mackerel), flaxseeds, walnuts, and soybeans.

Daily Requirements of Fats and Vitamins

  1. Fats

    • Adults should consume 20-35% of their daily calorie intake from fats.
    • Limit saturated fats to less than 10% and trans fats to less than 1% of daily caloric intake.

  2. Vitamins

    • Vitamin A: 700-900 µg/day
    • Vitamin D: 15-20 µg/day
    • Vitamin E: 15 mg/day
    • Vitamin K: 90-120 µg/day
    • Vitamin C: 75-90 mg/day
    • B-Complex: Varies by individual B-vitamin (e.g., B12: 2.4 µg/day)


Comments

Post a Comment