Topic 5 (Micronutrients) PDF

Topic 5 (Micronutrients) Key Vitamins Fat-Soluble Vitamins (A, D, E, K) Vitamin A Functions: Vision (retinal is a component of rhodopsin in the retina) Cell growth and differentiation (espe...

Topic 5 (Micronutrients) Key Vitamins Fat-Soluble Vitamins (A, D, E, K) Vitamin A Functions: Vision (retinal is a component of rhodopsin in the retina) Cell growth and differentiation (especially in skin and mucous membranes) Immune function (supports white blood cell production) Antioxidant Food Sources: Animal-based: Liver, dairy, eggs, fish Plant-based: Carrots, sweet potatoes, spinach (contain beta-carotene, a precursor) Deficiency Symptoms: Night blindness (early symptom) Xerophthalmia (severe deficiency leading to blindness) Toxicity: Liver damage, birth defects, nausea, dizziness People at Risk: Infants, pregnant women, people with fat malabsorption disorders Factors Affecting Absorption: Enhanced by dietary fat, bile salts Inhibited by excessive alcohol, low-fat diet Topic 5 (Micronutrients) 1  Vitamin D Functions: Calcium absorption and bone health Immune system support Muscle function and cardiovascular health Food Sources: Animal-based: Fatty fish (salmon, tuna), egg yolks, fortified dairy products Non-dietary: Synthesized in skin when exposed to sunlight Deficiency Symptoms: Rickets (children - soft bones) Osteomalacia (adults - weak bones) Toxicity: Hypercalcemia (excess calcium in blood), kidney damage People at Risk: Elderly, people with limited sun exposure, individuals with darker skin Factors Affecting Absorption: Enhanced by presence of dietary fat, adequate sun exposure Inhibited by lack of sunlight, low dietary fat intake Vitamin E Functions: Antioxidant (protects cells from oxidative stress) Maintains membrane integrity, especially in red blood cells Supports immune function Food Sources: Vegetable oils (sunflower, safflower), nuts (almonds, hazelnuts), seeds Topic 5 (Micronutrients) 2  Deficiency Symptoms: Hemolytic anemia (due to red blood cell breakdown) Neuromuscular dysfunction Toxicity: Increased risk of bleeding, impaired blood clotting People at Risk: Premature infants, individuals with fat malabsorption disorders Factors Affecting Absorption: Enhanced by dietary fat Inhibited by high heat and food processing Vitamin K Functions: Blood clotting (activates clotting factors) Bone mineralization (involved in osteocalcin activation) Food Sources: Leafy green vegetables (spinach, kale, broccoli) Some synthesis by gut bacteria Deficiency Symptoms: Increased bleeding time Toxicity: Rare, but can interfere with blood thinning medications People at Risk: Newborns (given Vitamin K injection at birth), people on long-term antibiotics Factors Affecting Absorption: Topic 5 (Micronutrients) 3  Enhanced by dietary fat Inhibited by excessive vitamin E intake Water-Soluble Vitamins Vitamin C Functions: Collagen synthesis (important for skin, blood vessels, and wound healing) Antioxidant (protects against free radicals) Enhances iron absorption (especially non-heme iron) Food Sources: Citrus fruits, strawberries, bell peppers, tomatoes Deficiency Symptoms: Scurvy (bleeding gums, poor wound healing) People at Risk: Smokers, individuals with poor fruit/vegetable intake Factors Affecting Absorption: Enhanced by presence of iron Inhibited by heat and prolonged storage Vitamin B Group Deficiency Vitamin Functions Food Sources People at Risk Symptoms Energy Beriberi (muscle Alcoholics, Whole grains, B1 (Thiamin) metabolism, weakness, malnourished pork, legumes nerve function nerve damage) individuals Energy Cracks at mouth Individuals with Dairy, eggs, B2 (Riboflavin) production, skin corners, poor dairy leafy greens and eye health inflamed tongue intake Topic 5 (Micronutrients) 4  Energy Pellagra Populations with metabolism, skin Meat, fish, (diarrhea, B3 (Niacin) diets reliant on and digestive whole grains dermatitis, corn health dementia) Amino acid Alcoholics, Poultry, B6 metabolism, Depression, individuals on bananas, (Pyridoxine) neurotransmitter confusion certain potatoes synthesis medications DNA synthesis, Leafy greens, Megaloblastic Pregnant B9 (Folate) prevents neural legumes, anemia, neural women, tube defects fortified grains tube defects alcoholics Vegetarians, Red blood cell Meat, dairy, Pernicious B12 elderly with formation, nerve eggs, fortified anemia, nerve (Cobalamin) reduced function cereals damage stomach acid Key Minerals Deficiency Mineral Functions Food Sources People at Risk Symptoms Red meat, Oxygen poultry, fish Iron-deficiency Women with transport, (heme); Beans, Iron anemia (fatigue, heavy periods, enzyme spinach, weakness) vegetarians function fortified cereals (non-heme) Bone health, Postmenopausal Dairy, leafy Osteoporosis muscle women, lactose- Calcium greens, fortified (weak bones, contraction, intolerant foods fractures) nerve function individuals Muscle and nerve function, Nuts, seeds, Muscle cramps, Alcoholics, Magnesium enzyme whole grains, irregular chronically ill cofactor, bone leafy greens heartbeat individuals health Sodium Fluid balance, Salt, processed Hyponatremia Endurance nerve foods, soy (weakness, athletes, people Topic 5 (Micronutrients) 5  transmission, sauce confusion) with excessive muscle sweating contraction Muscle Muscle contraction, Bananas, Individuals on weakness, Potassium nerve function, potatoes, beans, diuretics, high irregular blood pressure dairy sodium intake heartbeat regulation Memorisation Topic 5 (Micronutrients) 6