Iron bisglycinate is an amino acid chelate consisting of two molecules of the simplest amino acid, i.e. glycine, and an iron ion. Its unique structure, which is similar to complexes naturally occurring in our bodies, allows better absorption and a reduction in adverse events from the gastrointestinal tract compared to traditional salts. It is described as the salt with the highest bioavailability and safety.
Iron is one of the most important minerals necessary for the proper functioning of our body. Being a key component of hemoglobin, it builds red blood cells and is also part of the liver and muscle iron stores as ferritin and myoglobin. Unfortunately, despite its key role in the human body, deficiencies are relatively common, especially during periods of increased demand such as body growth, pregnancy and menstruation. Such deficiencies are usually caused by low intake of this macronutrient as well as poor absorption of some forms of iron from food. In this case, additional support in the form of dietary supplements is necessary. However, iron supplementation is difficult and often poorly tolerated due to adverse effects such as irritation of the gastric mucosa, which manifests itself as heartburn, nausea, constipation, diarrhea or abdominal pain. For this reason, scientists often conduct studies to improve the conditions of therapies aimed at supplementing deficiencies of this element.
A recent meta-analysis by researchers from the University of Oxford summarized the last several years of work by international research centers to evaluate the safety and efficacy of iron diglycinate compared to other iron supplements. Among other things, changes in hemoglobin and ferritin concentrations and gastrointestinal-related adverse events were analyzed.
It should be mentioned that a meta-analysis is considered one of the most reliable sources of scientific information. The basis for the creation of meta-analyses is the reliance on multiple research papers, which allows reliable conclusions to be drawn from even thousands of research papers.
In a meta-analysis of studies conducted and published up to July 17, 2020 on iron bisglycinate supplementation compared to other iron supplements, hemoglobin and ferritin concentrations were examined in adults (including pregnant women) and children. Compared to other iron supplements, taking iron bisglycinate for 4 to 20 weeks resulted in higher hemoglobin concentrations in pregnant women and significantly fewer gastrointestinal adverse events reported. It was noted that due to better absorption of chelate, it is also possible to use lower doses than with inorganic salts, where the bioavailability of supplemented iron ions is very low. This treatment simultaneously reduces the chances of side effects, thereby increasing the safety of this therapy.
„The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials”, Jordie A. J. Fischer, Arlin M. Cherian, Jeffrey N. Bone, and Crystal D. Karakochuk, NutritionReviews, Volume 81, Issue 8, August 2023, Pages 904–920, https://doi.org/10.1093/nutrit/nuac106 Published: February 2, 2023