From: http://training.fitness.com/supplements/mulit-vitamins-2-33823.html
Regarding Centrum or One-a-day's, multis come in one of three forms: synthetic, natural, and whole-food. A good way to differentiate is to learn to read labels. Synthetic multiples will have the vitamin C listed as ascorbic acid but will lack a boiflavanoid complex. Vitamin C should be ascorbic acid, but we cannot metabolize it properly without the presence of bioflavanoids, so make sure that somewhere on the label is a bioflavanoid complex. Reptiles and older orders of birds make ascorbic acid in their kidneys. Recent orders of birds and most mammals make ascorbic acid in their livers where the enzyme L-gulonolactone oxidase is required to convert glucose to ascorbic acid. Humans, guinea pigs, and some other primates are not able to make L-gulonolactone oxidase because of a genetic defect and are therefore unable to make ascorbic acid in their livers.
They will also have a synthetic vitamin E (dl-alpha tocopheryl). As a general rule, if your vitamin contains these, you can be certain it is synthetic (like Centrum). Natural multis will contain natural ingredients (thus, ascorbic acid and bioflavanoids and d-alpha tocopheryl). Another indication is that the raw materials used to produce either a natural or whole food multi can not be compressed into one pill. Usually a one-per-day formula is synthetic. While synthetic multis are really poorly absorbed (like twenty percent due to the rate of compression and lack of protein bonding), natural and whole food multis are much more readily assimilated by the body. Most of the chain store (Costco, Sam's, Wal Mart, etc) vits are synthetic and are not only poorly absorbed but also really bad for the body.
A whole food multi is one that was created from raw materials found in actual whole foods, not created in a chemist's lab somewhere. Studies have shown that synthetic vitamins contain- in addition to the actual vitamins- coal tars, artificial coloring, preservatives, starches, and sugars. Vitamins that come from whole food sources are protein-bonded, and are absorbed, utilized, and retained better than supplements that are not protein-bonded.
Chemically derived vitamins are not protein-bonded, and thus are not absorbed well. That's where the bioavailability comes in- it has to do with how much of the actual nutrient you absorb. Basically, scientists have created synthetic vitamins that are cheap to make and are supposed to be identical to their whole-food counterparts. They are not. A study using polarized light showed that when the light is placed through whole food vitamins, the light beam bends to the right, due to its molecular rotation. When the same light passes through a synthetic vitamin, the beam splits in half.
This proves 2 things- first, synthetic vitamins are not the same as whole food vits in their atomic structure, and second, researchers concluded that in a best case scenario, only 50% of the biological activity of the vitamin is available. (Vinson, JA., Bose P. "Comparative Bioavailabilty to Humans of Ascorbic Acid Alone or in Citrus Extract." American Journal of Clinical Nutrition, 1998, Vol 38, No 3, p. 601-604. AND Duke, James. Handbook of Chemical Constituants of Grasses, Herbs, and other Economical Plants. CRC Press, Boca Raton. 1992.) Add to that the fact that most synthetics are compressed at a rate of about 12,000 PSI's, and you're looking at maybe a 20% absorption rate.
Regarding Centrum or One-a-day's, multis come in one of three forms: synthetic, natural, and whole-food. A good way to differentiate is to learn to read labels. Synthetic multiples will have the vitamin C listed as ascorbic acid but will lack a boiflavanoid complex. Vitamin C should be ascorbic acid, but we cannot metabolize it properly without the presence of bioflavanoids, so make sure that somewhere on the label is a bioflavanoid complex. Reptiles and older orders of birds make ascorbic acid in their kidneys. Recent orders of birds and most mammals make ascorbic acid in their livers where the enzyme L-gulonolactone oxidase is required to convert glucose to ascorbic acid. Humans, guinea pigs, and some other primates are not able to make L-gulonolactone oxidase because of a genetic defect and are therefore unable to make ascorbic acid in their livers.
They will also have a synthetic vitamin E (dl-alpha tocopheryl). As a general rule, if your vitamin contains these, you can be certain it is synthetic (like Centrum). Natural multis will contain natural ingredients (thus, ascorbic acid and bioflavanoids and d-alpha tocopheryl). Another indication is that the raw materials used to produce either a natural or whole food multi can not be compressed into one pill. Usually a one-per-day formula is synthetic. While synthetic multis are really poorly absorbed (like twenty percent due to the rate of compression and lack of protein bonding), natural and whole food multis are much more readily assimilated by the body. Most of the chain store (Costco, Sam's, Wal Mart, etc) vits are synthetic and are not only poorly absorbed but also really bad for the body.
A whole food multi is one that was created from raw materials found in actual whole foods, not created in a chemist's lab somewhere. Studies have shown that synthetic vitamins contain- in addition to the actual vitamins- coal tars, artificial coloring, preservatives, starches, and sugars. Vitamins that come from whole food sources are protein-bonded, and are absorbed, utilized, and retained better than supplements that are not protein-bonded.
Chemically derived vitamins are not protein-bonded, and thus are not absorbed well. That's where the bioavailability comes in- it has to do with how much of the actual nutrient you absorb. Basically, scientists have created synthetic vitamins that are cheap to make and are supposed to be identical to their whole-food counterparts. They are not. A study using polarized light showed that when the light is placed through whole food vitamins, the light beam bends to the right, due to its molecular rotation. When the same light passes through a synthetic vitamin, the beam splits in half.
This proves 2 things- first, synthetic vitamins are not the same as whole food vits in their atomic structure, and second, researchers concluded that in a best case scenario, only 50% of the biological activity of the vitamin is available. (Vinson, JA., Bose P. "Comparative Bioavailabilty to Humans of Ascorbic Acid Alone or in Citrus Extract." American Journal of Clinical Nutrition, 1998, Vol 38, No 3, p. 601-604. AND Duke, James. Handbook of Chemical Constituants of Grasses, Herbs, and other Economical Plants. CRC Press, Boca Raton. 1992.) Add to that the fact that most synthetics are compressed at a rate of about 12,000 PSI's, and you're looking at maybe a 20% absorption rate.
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