Modern nutrition science began once vitamins got chemical names
Nutrition is how organisms turn food and water into energy and structure; too little or too much of essentials breeds malnutrition. Chemists probed diets in the late eighteenth century, but modern nutrition science took off in the 1910s as micronutrients were isolated one by one.
Roughly thirty elements appear in organic matter, led by nitrogen, carbon, and phosphorus. Macronutrients and micronutrients feed metabolic chains—fueling, biosynthesis, polymerisation, assembly. Heterotrophs eat other organisms’ carbon; autotrophs build from inorganic carbon such as carbon dioxide; mixotrophs switch. A healthy diet supplies vitamins, minerals, essential amino acids, and essential fatty acids alongside carbohydrate, protein, and fat.
Mineral nutrients cycle through soil, air, water, and bodies—carbon, nitrogen, phosphorus, sulfur, water—while energy flows one way. Foraging may be random or directed as animals navigate and plants extend roots. Deficiency is outright lack; inadequacy sits between deficiency and recommended intake, sometimes with hidden symptoms.
Animals as heterotrophs split into herbivores, carnivores, and omnivores; many plant-eaters lean on bacterial fermentation. Food energy is counted in Calories—kilocalories that raise one kilogram of water one degree Celsius. Carbohydrates store plant-made energy animals largely cannot invent; lipids, mostly triglycerides, pack long-term fuel.
Protein is split into amino acids that animals reassemble into new proteins for cell structures, body fluids and enzymes, the catalysts behind most metabolism and behind copying and repairing DNA; each gram yields 4 calories. Lipids do not dissolve in water, which suits them to storing energy for long spells. Daily Reference Values are not personal prescriptions but reference ranges for professionals, policymakers and food labels, since lacking even one essential nutrient can cause harm and an excess can be toxic. Feeding also shapes behaviour: migrations and breeding seasons track food supply, courtship displays advertise health, animals learn to shun foods that once made them ill, and rats ignore unfamiliar foods unless short of some nutrient.
Source: Nutrition
