The scientific definition of a vitamin is “an organic compound, not a lipid or amino acid, required in very small amounts for essential functions in the body.” Anything that’s organic—from mulch and tree trunks to toenails and earlobes—contains the element carbon, the same element that’s found in every vitamin. Lipids (fats) and amino acids are also organic, but they are not vitamins.
The customary means of getting vitamins into our bodies is to eat plants or animals that make or store these compounds. Plants use sunlight, air, water, and nutrients from the soil to synthesize folate in their leaves. Some plants and animals make their own vitamin C. Vitamins can also be synthesized from organic compounds in a laboratory. Thus, when you buy a vitamin supplement, you might be getting compounds that have been put together by plants and animals, or you might be getting identical, look-alike compounds that have been assembled in a laboratory.
Minerals are inorganic, but these, too, are available from organic sources. Plants absorb minerals from the ground, and animals get them from the plants they eat, so the root source of all minerals is the Earth.
By definition, anything officially labeled a “vitamin” is in some way absolutely necessary to human health. “If a substance found in food has a defined biochemical function in the human body, it is considered essential,” says Forrest Nielsen, Ph.D., director of the U.S. Department of Agriculture (USDA) Human Nutrition Research Center in Grand Forks, North Dakota. It may take many years of research, however, before scientists know whether a component is essential, he adds.
Essential nutrients may be parts of hormones. The trace mineral iodine, for instance, is needed to manufacture thyroxine, the thyroid gland’s major hormone. Nutrients may also be needed to break down food for energy, as many of the B vitamins are.
| Where Phytos Finish in the Nutrient Race When it comes to stocking your body with nutrients, the essentials are just that—essential. They include protein, carbohydrates, fats, vitamins, minerals, and water. Then there are the phytonutrients. Phyto means “plant,” so phytonutrients are simply nutrients derived from plants. Phytonutrients may promote good health, but unlike vitamins, they have not been found to be essential, says Cyndi Thomson, R.D., Ph.D., clinical nutrition research specialist at the University of Arizona Cancer Prevention Center in Tucson.
Then where does that leave our green vegetables? Weren’t we all told to eat our peas and broccoli or we’d wither and fade away? Despite what you were told, or even what you told your kids, “you will not die if you do not eat broccoli—but you may not be as healthy, either,” Dr. Thomson says. In fact, there’s only one class of phytonutrients, the carotenoids, that has been shown to have vitamin activity. The beta-carotene that you get from carrots and some other fruits and vegetables is changed by your body into different compounds, one of which is much-needed vitamin A. So, even though you can survive without vegetables, you do need them. While it’s true that some phytonutrients are available as nutritional supplements, no matter how “complete” the supplements are, they’re bound to leave out many of the phytos that are found in fruits and vegetables. Not only that, but the mixture of these nutrients that you get naturally from carrots, blueberries, broccoli, and other plant foods provides some benefits that generally can’t be duplicated by a laboratory-produced pill. You’re better off supplementing your diet with a wide range of fresh fruits and vegetables. Especially good sources of the phytonutrients that will help you thrive are berries, garlic, dark leafy greens, deep yellow and orange fruits and vegetables, grape juice, tomatoes, and, yes, broccoli. |
Nutrients can also break down wastes that are subsequently eliminated from the body. The trace mineral manganese serves this role, converting the toxic ammonia that we form in our bodies into urea, which is excreted in urine.
Some nutrients appear to be essential even though their biochemical functions have yet to be defined, Dr. Nielsen says. Chromium, nickel, and boron are examples. Arsenic, a substance that we label as poison, is one of the possibly essential nutrients under investigation, since we don’t know why our bodies need it.
It’s likely that more nutrients will make the “essential” list as research continues. “There are a lot of gray areas left to explore,” says Gerald Combs Jr., Ph.D., professor of nutrition at Cornell University in Ithaca, New York. He cites omega-3 fatty acids and the amino acid carnitine as two examples. “Now we realize that omega-3 fatty acids are required for neurological development and eye development in infants,” says Dr. Combs. “Some experts also think that carnitine may be required for infants under some circumstances.”
As we develop better technology, we can scrutinize the additional properties of vitamins and minerals even more closely, Dr. Combs adds. “We can measure things we couldn’t even conceive of earlier.” Within the last four decades, for example, the ability to measure zinc has improved tremendously. “Twenty-five years ago, we thought there were five or six zinc-containing enzymes because that’s all we could measure,” Dr. Combs observes. “Now we know there are two or three hundred, simply because we can detect tinier and tinier amounts.”
Article Source: MotherNature.com
