Vitamins--don't get me started!

Of all the nutritional information about which pseudoscience, quackery, and charlatanism abound, that concerning vitamins is the most rampant and egregious.
Vitamins are co-enzymes or catalysts that are involved in the production of proteins. They are required only in small amounts., and must be obtained in the diet. There are diseases caused by deficiency of certain vitamins (scurvy, pellagra, beriberi are three examples) AND THERE ARE DISEASES CAUSED BY EXCESS INTAKE OF CERTAIN VITAMINS (hypervitaminosis A, excess vitamin E as just two). They are not magical cures for anything EXCEPT their specific deficiency, which is rarely an issue in the U.S. In addition, as chemical molecules there is NO DIFFERENCE between a "natural" vitamin and one that is manufactured--the structures are, of necessity, identical. Americans spend literally billions of dollars every year on vitamins, most of them not necessary. The science is out there about this issue--look for it!