MAGNESIUM is one of the best-selling nutritional supplements in the world. However, most people do not realize that many of the top selling brands contain Magnesium Oxide which has the lowest rate of absorption of all forms at only 4%. The form with the highest rate of absorption is Magnesium Aspartate at 40% or 10 times greater than the oxide form. Next is Magnesium Citrate at 30% absorption. One of the most popular forms is Magnesium Glycinate that only has a 24% rate of absorption. Other forms of magnesium have a 24% or lower rate of absorption. ZMA contains Magnesium Aspartate with the highest rate of absorption. Consumers should be aware of what are called "buffered" magnesium supplements. One of the forms with a higher rate of absorption is often blended or "buffered" with magnesium oxide. IMO this is simply a form of trickery designed to mislead consumers. It is also important to understand that each capsule can only contain about 150 milligrams of elemental magnesium in a bioavailable form. If a product label claims that a capsule contains more than 150 milligrams then it is likely "buffered" or "blended" or a "complex" that contains magnesium oxide. Finally, the regulations require that ingredients be listed in order of concentration. So if magnesium oxide is listed first and other more bioavailable forms of magnesium are listed thereafter, the product likely contains a very low overall rate of magnesium absorption. Many of the best-selling brands contain magnesium oxide because companies realize that most consumers do not understand the absorption rates of the different forms. BUYER BEWARE.
