Iron deficiency is a cause of many health problems among adults and children. They affect not only the quality of daily functioning but may also disrupt a number of metabolic processes. Iron deficiency is particularly dangerous in pregnant women and is associated with an increased risk of anemia, preterm birth, low birth weight, impaired child development, and postpartum depression.
Iron supplementation most commonly involves inorganic or organic iron salts, such as ferrous sulfate or ferrous fumarate. Their use may be associated with adverse effects, especially gastrointestinal side effects.
One possible source of iron is also ferrous bisglycinate. Unlike traditional iron salts, it belongs to the group of amino acid chelates. Studies indicate that this form may have higher bioavailability compared with conventional iron salts. Ferrous bisglycinate is a compound in which an iron ion is bound to two glycine molecules. This structure may protect the iron ion during its passage through the gastrointestinal tract, potentially promoting more effective absorption.
One of the studies evaluating the bioavailability, efficacy, and safety of ferrous bisglycinate supplementation was a randomized, controlled trial conducted among pregnant women with iron deficiency. The study compared a preparation containing 24 mg of elemental iron as ferrous bisglycinate with one containing 66 mg of elemental iron as ferrous fumarate.
The study was conducted among 120 pregnant women aged 20–40 years who were between the 12th and 16th weeks of pregnancy. Only patients with confirmed iron deficiency, defined as a ferritin concentration of <30 μg/L, were eligible for participation. The exclusion criteria included, among others, women with gestational diabetes, preeclampsia, thalassemia, hemoglobinopathies, chronic gastrointestinal diseases, as well as individuals who smoked cigarettes or abused alcohol. Participants were randomly assigned to one of two groups. The study group received a daily capsule containing 120 mg of ferrous bisglycinate (24 mg of elemental iron), folinic acid, and a vitamin complex. The control group received a preparation containing 200 mg of ferrous fumarate, providing 66 mg of elemental iron, also enriched with vitamins. Supplementation continued for six months, and the preparations were taken daily after breakfast. During the study, iron bioavailability, changes in hematological parameters, and the safety of both preparations were assessed.
The effects of supplementation were evaluated through analysis of iron bioavailability, hematological parameters, and indicators of iron metabolism.
Immediately after the first dose of the preparation, fasting serum iron concentrations were measured, as well as one and two hours after supplementation, in order to assess the body’s response to administration of both forms of iron. Additionally, before the start of the study and after three and six months of supplementation, the following parameters were measured: hemoglobin concentration, erythrocyte and reticulocyte counts, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), transferrin saturation, ferritin concentration, and high-sensitivity C-reactive protein (hs-CRP) levels. Throughout the observation period, gastrointestinal adverse effects were also monitored. Participants’ quality of life was assessed using the standardized WHOQOL-BREF questionnaire, and newborn birth weights were analyzed. Differences were considered statistically significant at p < 0.05.
After six months of supplementation, significant improvements in hematological parameters and iron metabolism were observed in both groups. The group receiving ferrous bisglycinate showed greater changes in hemoglobin and ferritin concentrations, as well as in other analyzed indicators, compared with the control group, despite receiving a lower dose of elemental iron. Additionally, participants using ferrous bisglycinate reported adverse effects such as nausea, abdominal pain, bloating, constipation, and a metallic taste in the mouth less frequently.
The results of this study are consistent with previous scientific reports indicating that ferrous bisglycinate may be an effective alternative to traditional iron salts while providing better gastrointestinal tolerance. This is particularly important for individuals in whom supplementation with conventional iron forms causes discomfort that interferes with regular use of the preparation.
The combination of favorable bioavailability, clinically confirmed efficacy, and good tolerability makes ferrous bisglycinate a form of iron used in preparations intended for individuals requiring iron supplementation, including products targeted at pregnant women.
Based on:
Bumrungpert, A., Pavadhgul, P., Piromsawasdi, T., & Mozafari, M. R. (2022). Efficacy and safety of ferrous bisglycinate and folinic acid in the control of iron deficiency in pregnant women: A randomized, controlled trial. Nutrients, 14(3), 452. https://doi.org/10.3390/nu14030452
