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Basic Nutritional Requirements

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Energy & Macronutrients - Fuel & Builders

  • Energy: Unit Kcal. 1 Kcal = heat to raise 1kg water by 1°C.
    • Fuel Values (Kcal/g): CHO 4, Protein 4, Fat 9. (Alcohol 7 Kcal/g).
  • BMR: Minimum energy at rest. SDA/TEF: Energy to metabolize food (Protein highest ~30%).
  • Macronutrients (% daily energy):
    • Carbohydrates (CHO): 50-60%. Primary fuel.
    • Proteins: 10-15% (0.8-1 g/kg/day). Body building.
      • 📌 Essential AAs: PVT TIM HALL.
    • Fats: 20-30%. Concentrated energy; EFA (Linoleic $\omega$-6, Linolenic $\omega$-3) deficiency → phrynoderma. Energy density of macronutrients per gram

⭐ Atwater General Factors for physiological fuel values: Carbohydrates 4 Kcal/g, Proteins 4 Kcal/g, Fats 9 Kcal/g.

Fat-Soluble Vitamins - ADEK Superstars

  • Absorbed with fats; stored (liver, adipose); risk of toxicity. 📌 Mnemonic: "Fat ADEK".
  • A (Retinol): Vision, epithelial integrity, immunity.
    • Deficiency: Night blindness, Bitot's spots, xerophthalmia.
    • Prophylaxis: 1L IU (6-11mo), 2L IU (1-6yr) q6mo.
  • D (Calciferol): $Ca^{2+}/PO_4^{3-}$ balance, bone health.
    • Deficiency: Rickets, osteomalacia.
    • Sources: Sunlight ($D_3$), diet ($D_2, D_3$).
  • E (Tocopherol): Antioxidant, cell membrane protection.
    • Deficiency: Rare; hemolytic anemia, neuropathy.
  • K (Phylloquinone/Menaquinone): Clotting factors (II, VII, IX, X, C, S).
    • Deficiency: Bleeding; Hemorrhagic Disease of Newborn (HDN).
    • HDN Prophylaxis: 1 mg IM at birth. Fat-Soluble Vitamins ADEK: Sources, Functions, Deficiency

⭐ Vitamin A deficiency is a leading cause of preventable childhood blindness globally.

Water-Soluble Vitamins - B-C Vitality

  • General: Not stored (except B12); excess excreted. Coenzymes.
  • B-Complex:
    • B1 (Thiamine): TPP (carb metabolism). Deficiency: Beriberi, Wernicke-Korsakoff.
    • B2 (Riboflavin): FAD/FMN (redox). Deficiency: Ariboflavinosis (cheilosis, glossitis).
    • B3 (Niacin): NAD/NADP (from tryptophan). Deficiency: Pellagra (3Ds: Dermatitis, Diarrhea, Dementia).
    • B6 (Pyridoxine): PLP (amino acid metabolism). Deficiency: Neuropathy, sideroblastic anemia. Isoniazid ↑need.
    • B9 (Folate): THF (DNA synthesis). Deficiency: Megaloblastic anemia, NTDs. RDA (Pregnancy): 600 mcg.
    • B12 (Cobalamin): DNA synthesis, myelin. Needs intrinsic factor. Deficiency: Megaloblastic anemia, neurological damage.
  • Vitamin C (Ascorbic Acid): Antioxidant, collagen synthesis, ↑non-heme Fe absorption. Deficiency: Scurvy.

Clinical Manifestations of Vitamin Deficiencies

⭐ High dose niacin (B3) is used for hyperlipidemia but can cause flushing (prostaglandin-mediated).

Essential Minerals - Micro Mighty

  • Iron (Fe): O₂ transport (Hb, Mb); enzyme cofactor. Deficiency: Microcytic anemia, koilonychia, pica. RDA: Men 8 mg, Women 18 mg (pre-menopause).
  • Iodine (I): Thyroid hormones ($T_3, T_4$). Deficiency: Goiter, cretinism, hypothyroidism. RDA: 150 µg.
  • Zinc (Zn): Cofactor for >300 enzymes; immunity, wound healing, taste/smell. Deficiency: Growth retardation, acrodermatitis enteropathica, ↓immunity, delayed wound healing.
  • Selenium (Se): Antioxidant (glutathione peroxidase); thyroid hormone metabolism. Deficiency: Keshan disease (cardiomyopathy), Kashin-Beck disease.
  • Copper (Cu): Iron absorption/transport; enzyme cofactor (e.g., lysyl oxidase, cytochrome c oxidase). Deficiency: Menkes kinky hair syndrome, anemia. Excess: Wilson's disease.
  • Fluoride (F⁻): Dental/bone health; prevents caries. Optimal water fluoridation: 0.7 ppm. Excess: Dental & skeletal fluorosis.
  • Chromium (Cr): Glucose tolerance factor; potentiates insulin action.
  • Manganese (Mn): Enzyme activator (e.g., mitochondrial superoxide dismutase).
  • Molybdenum (Mo): Cofactor for xanthine oxidase, sulfite oxidase. Minerals: RDAs, dietary sources, deficiency, excess

⭐ Zinc deficiency is classically associated with acrodermatitis enteropathica, characterized by periorificial and acral dermatitis, alopecia, and diarrhea.

High‑Yield Points - ⚡ Biggest Takeaways

  • A balanced diet is crucial, supplying macronutrients (carbohydrates, proteins, fats) and micronutrients (vitamins, minerals).
  • Average adult energy requirement (sedentary Indian male): ~2100-2300 kcal/day.
  • Protein RDA: 0.8-1 g/kg body weight/day; requirements ↑ during growth, pregnancy, and lactation.
  • Essential Fatty Acids (EFAs) like linoleic acid and alpha-linolenic acid must be diet-derived.
  • Recommended Dietary Allowances (RDAs) are average daily nutrient intake levels sufficient for most healthy individuals.
  • Basal Metabolic Rate (BMR) accounts for the largest portion (~60-70%) of total energy expenditure.
  • Specific Dynamic Action (SDA), or thermic effect of food, is highest for proteins (~30%).

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A patient on a maize diet presented with diarrhea, dementia and dermatitis. Which vitamin deficiency is responsible for these features

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_____ promotes greater retention of ingested fluoride, leading to fluorosis

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_____ promotes greater retention of ingested fluoride, leading to fluorosis

Jowar (sorghum) (Millet)

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