Vitamins: Fat-Soluble Vitamins (A, D, E, K) (Junior Cert Home Economics): Revision Notes

Vitamins: Fat-Soluble Vitamins (A, D, E, K)

Classification of Vitamins

• Fat-Soluble Vitamins:
  • Includes A, D, E, and K.
  • Stored in the body in fatty tissues.
  • Overconsumption (through supplements) can cause hypervitaminosis (toxic levels), particularly with vitamins A and D.
• Water-Soluble Vitamins:
  • Includes B group and C.
  • Not stored in the body, so daily intake is essential.

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Fat-Soluble Vitamins (A, D, E, and K)

Vitamin A

• Sources:
  • Pure vitamin A: Oily fish, eggs, butter.
  • Carotene (provitamin A): Carrots, peppers, dark green vegetables.
• Functions:
  • Maintains good eyesight.
  • Keeps the linings of the nose, mouth, and throat healthy.
  • Promotes growth and keeps eyes, skin, and hair healthy.
• Deficiencies:
  • Night blindness (difficulty seeing in dim light).
  • Dry, irritated skin.
  • Delayed growth.

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Vitamin D

• Sources:
  • Sunshine, oily fish, fish liver oils, tinned fish (e.g., sardines), cheese, butter, eggs, margarine.
• Functions:
  • Helps the body absorb calcium, promoting strong bones and teeth.
• Deficiencies:
  • Rickets (soft, deformed bones in children).
  • Osteomalacia (soft, weak bones in adults).
  • Tooth decay.

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Vitamin E

• Sources:
  • Seeds, nuts, cereals.
• Functions:
  • Protects against heart disease.
  • Maintains healthy skin.
• Deficiencies:
  • Rare.

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Vitamin K

• Sources:
  • Green vegetables, milk, cheese.
  • Produced by healthy bacteria in the intestines.
• Functions:
  • Essential for normal blood clotting.
• Deficiencies:
  • Blood does not clot normally (extremely rare).

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Key Takeaway

Fat-soluble vitamins are vital for growth, development, and maintaining overall health. A balanced diet rich in these vitamins prevents deficiencies and promotes well-being. Avoid over-supplementing to prevent toxicity.