Chapter Nutrition Complete Vitamins Explained Vitamin A B C D E K
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Overview of Vitamins
Vitamins are organic micronutrients required in small amounts for growth, metabolism, and maintenance of health. They fall into two categories:
- Fat-soluble: A, D, E, K (stored in body fat)
- Water-soluble: C and B group (not stored extensively; excess excreted)
Vitamin A
Functions: Vision (retinal), immune support, skin health.
Sources: Liver, dairy, eggs, orange/yellow vegetables (carrots, sweet potatoes), leafy greens.
Deficiency: Night blindness, dry skin, increased infection risk.
Vitamin B Complex
Vitamin | Role | Sources | Deficiency |
---|---|---|---|
B₁ (Thiamine) | Energy metabolism, nerve function | Whole grains, pork, legumes | Beriberi, Wernicke-Korsakoff |
B₂ (Riboflavin) | Energy, redox reactions | Dairy, eggs, green vegetables | Ariboflavinosis (mouth sores) |
B₃ (Niacin) | DNA repair, metabolism | Meat, legumes, cereals | Pellagra (dermatitis, dementia) |
B₅ (Pantothenic Acid) | CoA synthesis | Widespread: meat, whole grains | Rare (fatigue) |
B₆ (Pyridoxine) | Amino acid metabolism | Meat, bananas, potatoes | Anemia, neuropathy |
B₇ (Biotin) | Carb & fat metabolism | Eggs, nuts, seeds | Hair loss, dermatitis |
B₉ (Folate) | DNA synthesis, pregnancy | Leafy greens, legumes | Megaloblastic anemia, neural tube defects |
B₁₂ (Cobalamin) | Red blood cells, nerve health | Animal products | Pernicious anemia, neuropathy |
Vitamin C
Functions: Collagen synthesis, antioxidant, iron absorption.
Sources: Citrus fruits, berries, peppers, broccoli.
Deficiency: Scurvy (bleeding gums, poor wound healing).
Vitamin D
Functions: Calcium/phosphate homeostasis, bone health.
Sources: Sunlight (skin synthesis), fatty fish, fortified dairy.
Deficiency: Rickets in children, osteomalacia in adults.
Vitamin E
Functions: Antioxidant protecting cell membranes.
Sources: Vegetable oils, nuts, seeds, green vegetables.
Deficiency: Rare; nerve and muscle damage.
Vitamin K
Functions: Blood clotting (coagulation factors), bone metabolism.
Sources: Leafy greens, fermented foods, gut bacteria synthesis.
Deficiency: Bleeding tendency, poor bone health.