How long does it take for vitamins to enter blood stream and cells?

Vitamins can enter the bloodstream relatively quickly after ingestion, typically within 30 minutes to a few hours, depending on the type of vitamin and its form (such as food or supplement). Water-soluble vitamins, like vitamin C and B vitamins, are absorbed more rapidly than fat-soluble vitamins, such as A, D, E, and K. Once in the bloodstream, it may take additional time for vitamins to be delivered to cells, often ranging from a few hours to several days, based on individual metabolism and the body's needs.