Chapter 11: Nutrition

Vitamins function as metabolic catalysts and are classified as either fat-soluble with storage capacity and potential toxicity concerns or water-soluble and excreted through urine without long-term storage. Minerals and electrolytes regulate osmolarity and neuromuscular function, while water comprises the majority of body weight and is critical for survival. Nutritional assessment relies on laboratory markers such as prealbumin and transferrin for short-term protein evaluation and serum albumin for long-term status determination. Dietary guidelines emphasize balanced plate composition with adequate fruits, vegetables, whole grains, and low-fat dairy products. Across the lifespan, nutritional requirements shift dramatically, from breastfeeding recommendations in infancy through increased calcium and iron needs during adolescence to modified intake in older adults who experience decreased metabolic rates and medication interactions. Pregnancy and lactation demand elevated protein consumption and micronutrient supplementation. Therapeutic diets address specific medical conditions through texture modification, nutrient restriction, and composition adjustments, including clear and full liquid options for digestive concerns, mechanical soft and regular soft diets for swallowing difficulties, cardiac diets limiting sodium and fat for hypertension management, renal diets restricting protein and electrolytes for kidney disease, and disease-specific approaches such as low-purine diets for gout prevention. Special populations including vegetarian and vegan individuals require education about complementary protein combinations to ensure complete amino acid intake and prevention of micronutrient deficiencies in vitamin B12, zinc, and iron. Enteral nutrition provides essential sustenance through tube feeding when oral intake is compromised but gastrointestinal function remains intact.