Nutritional diseases

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Protein-Energy Malnutrition - Empty Plate Problems

  • A spectrum of diseases from inadequate protein and calorie intake, primarily affecting somatic (skeletal muscle) and visceral (organ) protein compartments.

  • Marasmus (Total Calorie Deficiency)

    • Adaptation to starvation; "to waste away."
    • Clinical: Severe muscle wasting (emaciation), loss of subcutaneous fat, prominent bones, "old man" face.
    • Labs: Serum albumin is near-normal.
    • Somatic protein compartment depleted.
  • Kwashiorkor (Protein Deficiency > Calorie Deficiency)

    • Maladaptive response; "sickness of the weaned child."
    • Clinical: Pitting edema, ascites, hepatomegaly (fatty liver), "flaky-paint" dermatosis, alternating hair color (flag sign).
    • Labs: Markedly ↓ serum albumin.
    • Visceral protein compartment depleted.

High-Yield: The fatty liver in Kwashiorkor is due to decreased apolipoprotein synthesis, which impairs the export of VLDL from the liver.

Fat-Soluble Vitamins - ADEK's Fat Stash

  • Absorbed with lipids; deficiencies seen in malabsorption (celiac, cystic fibrosis) and with mineral oil intake. 📌 All Dogs Eat Kibble.
VitaminCore Function(s)Deficiency ManifestationsExcess Manifestations
A (Retinol)Vision, antioxidant, epithelial cell differentiationNight blindness, xerophthalmia, Bitot spotsTeratogenic, hepatotoxicity, alopecia
D (Calciferol)↑ Ca²⁺ & PO₄³⁻ absorptionRickets (kids), osteomalacia (adults)Hypercalcemia, confusion
E (Tocopherol)Antioxidant (protects RBCs)Hemolytic anemia, spinocerebellar tract demyelination↑ Warfarin effect, bleeding
K (Phytonadione)Coagulation factors (II, VII, IX, X, C, S)Hemorrhage, ↑ PT/PTTHemolytic anemia (high doses)

Vitamin A absorption, metabolism, and transport

Water-Soluble Vitamins - B & C's Washout

  • General: Absorbed in the small intestine; excess excreted in urine. Not stored in the body (except B12, B9), requiring consistent dietary intake. Act as crucial coenzymes in metabolic pathways.

  • Vitamin C (Ascorbic Acid)

    • Function: Antioxidant; essential for collagen synthesis (hydroxylation of proline/lysine).
    • Deficiency (Scurvy): Impaired wound healing, bleeding gums, perifollicular hemorrhage. Scurvy: Pelkan spur, Frankel line, Wimberger ring sign
  • B-Complex Vitamins

    • Function: Coenzymes in energy metabolism (e.g., Thiamine in PDH complex).
    • 📌 Mnemonic: B vitamins are coenzymes for "Burning" fuel.

Thiamine (B1) Deficiency: In alcoholics, can lead to Wernicke-Korsakoff syndrome. Always give thiamine before glucose to prevent precipitating encephalopathy.

Essential Minerals - Tiny But Mighty

  • Iron (Fe): O₂ transport (Hb, myoglobin); cytochrome function.
    • Deficiency: Microcytic, hypochromic anemia; koilonychia.
    • Excess: Hemochromatosis (organ damage from iron deposition).
  • Iodine (I): Synthesis of thyroid hormones ($T_3, T_4$).
    • Deficiency: Goiter, hypothyroidism, cretinism.
  • Copper (Cu): Cofactor for lysyl oxidase, tyrosinase, cytochrome c oxidase.
    • Deficiency (Menkes): Brittle, "kinky" hair, growth retardation.
    • Excess (Wilson's): Kayser-Fleischer rings, liver disease.
  • Zinc (Zn): Cofactor for >100 enzymes (e.g., carbonic anhydrase).
    • Deficiency: Delayed wound healing, hypogonadism, dysgeusia.

Acrodermatitis enteropathica, a rash around body orifices, is a classic sign of severe Zinc deficiency, often tested alongside delayed wound healing and anosmia/dysgeusia.

High‑Yield Points - ⚡ Biggest Takeaways

  • Marasmus results from total calorie malnutrition, leading to severe muscle wasting and loss of subcutaneous fat.
  • Kwashiorkor is primarily a protein deficiency, characterized by pitting edema, fatty liver, and skin lesions.
  • Vitamin A deficiency classically presents with night blindness (nyctalopia) and Bitot's spots on the conjunctiva.
  • Vitamin C deficiency impairs collagen synthesis, causing scurvy (bleeding gums, poor wound healing).
  • Vitamin D deficiency leads to Rickets in children and Osteomalacia in adults.

Practice Questions: Nutritional diseases

Test your understanding with these related questions

A 21-year-old woman presents to the clinic complaining of fatigue for the past 2 weeks. She reports that it is difficult for her to do strenuous tasks such as lifting heavy boxes at the bar she works at. She denies any precipitating factors, weight changes, nail changes, dry skin, chest pain, abdominal pain, or urinary changes. She is currently trying out a vegetarian diet for weight loss and overall wellness. Besides heavier than usual periods, the patient is otherwise healthy with no significant medical history. A physical examination demonstrates conjunctival pallor. Where in the gastrointestinal system is the most likely mineral that is deficient in the patient absorbed?

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Flashcards: Nutritional diseases

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What type of cells are the following examples? _____ ,smooth muscle cells

TAP TO REVEAL ANSWER

What type of cells are the following examples? _____ ,smooth muscle cells

Stable (Quiescent) (Labile, Stable, or Permanent?)

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