The process through which cells absorb nutrients is called nutrient uptake or more broadly absorption. This involves the transport of essential substances, such as vitamins, minerals, and macromolecules, across the cell membrane into the cell. Various mechanisms facilitate nutrient uptake, including passive diffusion, facilitated diffusion, and active transport. Active transport requires energy input to move substances against their concentration gradient. Efficient nutrient uptake is vital for cellular metabolism, growth, and overall organismal health, as it provides the building blocks necessary for various physiological processes.