Both vitamin pills and vegetables are loaded with essential nutrients, but not in the same combinations. Spinach is a good source of both vitamin C and iron. As it happens, vitamin C boosts iron absorption, allowing the body to take in more of it than if the mineral were introduced alone. When I first started studying nutrition, I became fascinated with these coincidences, realizing of course they're not coincidences. Human bodies and their complex digestive chemistry evolved over millenia in response to all the different foods--mostly plants--they raised or gathered from the land surrounding them. They may have died young from snakebite or blunt trauma, but they did not have diet-related illnesses like heart disease and Type II diabetes that are prevalent in our society now, even in some young adults and children. [from an entry by Barbara Kingsolver's daughter Camille]