Multivitamin and mineral supplements are the most widely used supplements in the United States, as well as in other industrialized countries. However, minerals commonly included in multivitamin supplements, such as iron in the form of ferric acid, can cause antioxidant vitamins, such as C and E, to oxidize, meaning that antioxidants may be lost before they are absorbed by the digestive system.
New research published in Nutrition Journal looked at inulin – a fructose-based oligosaccharide – in combination with amino acids as a supporting matrix in order to facilitate mineral solubility while also blunting the tendency of redox active metals to cause unwanted oxidations.
“Besides quality ingredients and the amount of each ingredient in a product, bioavailability is a major concern,” the authors wrote.
“…Formulations of multivitamin supplements typically include oxidation-sensitive vitamins, such as vitamin C and E, as well as minerals, such as iron and copper, in the same formulation. Minerals can have limited solubility, depending on their exact form. In addition redox active transition metals, such as iron and copper, can serve as catalysts for the oxidation of organic compounds.”
The researchers said that fructose-based oligosaccharides, such as inulin, have been shown to increase absorption of calcium, magnesium, iron, and zinc. And they found that using inulin in combination with amino acid complexes of copper – in the form of glycinate or aspartate – brought about even greater decreases in oxidation of tocopherols and ascorbate (forms of vitamin E and C respectively).
“Inulin appears to have many positive health effects. Our results suggest another positive effect of oligosaccharide in that AAOS offers significant advantages when included in the matrix for the formulation of dietary supplements,” the authors concluded.
They said that it is also possible that oxidations catalyzed by redox active forms of mineral supplements may also cause oxidative problems in tissues upon ingestion.
“As always there are risks and benefits that need to be understood. Improved formulation of multivitamin/multimineral supplements could both decrease risks and increase benefits,” the researchers wrote.
Source: Nutrition Journal
Issue 9 Volume 61 doi:10.1186/1475-2891-9-61
“Minimization of free radical damage by metal catalysis of multivitamin/multimineral supplements”
Authors: Alexander B. Rabovsky, Andrei M. Komarov, Jeremy S. Ivie, Garry R. Buettner