What are vitamins and how do they work?– Joseph Night, San Antonio, Texas
Jane Higdon, a nutrition scientist at Oregon State University, answers:
Vitamins are carbon-containing (organic) compounds that we need in small amounts to keep our body’s biological processes running properly. The term vitamin was coined in 1911 by Polish researcher Casimir Funk to denote vital substances that were originally thought to be chemical compounds called amines. As more vitamins were isolated, it became clear that their chemical structures were as varied as their functions. Biotin, folate, niacin, pantothenic acid, riboflavin, thiamine, vitamin B6, vitamin B12, vitamin C, and vitamin K all contribute to the efficient function of various life-sustaining enzymes, proteins that speed up biochemical reactions. Vitamin A and vitamin D are precursors to hormones that influence biological processes by entering the nucleus of a cell, binding to DNA, and altering the transcription of certain genes. Vitamin E and vitamin C are potent antioxidants that help protect the body from damage caused by reactive molecules generated during metabolism or by exposure to toxins. During the last century, scientists discovered more than a dozen vitamins and determined minimum intake levels needed to prevent deficiency-related diseases such as scurvy and beriberi. Now researchers are working to determine whether vitamin intake levels can be fine-tuned to help prevent chronic diseases.