Ferrous Bisglycinate Outperforms Other Iron Salts For Pregnant Women: Systematic Review & Meta-Analysis

Iron deficiency is the most common micronutrient deficiency, affecting an estimated 2 billion people globally1, with children and pregnant women at particular risk. This deficiency can have severe consequences across all stages of life, impacting physical and cognitive development in children, affecting pregnancy, and reducing the quality of life in adults. As a result, addressing and preventing iron deficiency in vulnerable populations is a global health priority.

Research has shown that the form of iron supplementation is as critical as the dosage

Traditional iron salts, such as ferrous sulfate and ferrous gluconate have long been the go-to solution for oral iron supplementation, despite poor bioavailability, gastrointestinal side effects, and requiring high dosages for treatment. However, in recent years, ferrous bisglycinate has emerged as a promising alternative; offering superior bioavailability and fewer gastrointestinal issues compared to conventional iron salts. ­

To provide a comprehensive assessment of ferrous bisglycinate’s supplementation, resear­­chers conducted a systematic review and meta-analysis of 17 randomized controlled trials (RCTs) to evaluate its effects on haemoglobin and ferritin concentrations, as well as GI adverse events on children and pregnant women.

Findings

Haemoglobin Concentrations: When comparing ferrous bisglycinate supplementation for 4 – 20 weeks with other iron supplements, pregnant women experienced a significant improvement in haemoglobin concentrations. The standardized mean difference (SMD) was 0.54 g/dL, with a 95% confidence interval (CI) of 0.15–0.94 (P<0.01).

GI Adverse Events: A standout advantage of ferrous bisglycinate was its association with fewer reported gastrointestinal adverse events in pregnant women. The incidence rate ratio (IRR) for these events was 0.36, with a 95% CI of 0.17 to 0.76 (P<0.01). This suggests a substantial reduction in gastrointestinal side effects, enhancing the tolerability of the supplement.

Conclusion

In summary, the recent systematic review and meta-analysis provide compelling evidence in favour of ferrous bisglycinate as a superior alternative to traditional iron supplements, especially for pregnant women. The significant increase in haemoglobin concentrations and the reduction in gastrointestinal adverse events among this group indicate its potential to address iron deficiency more effectively and comfortably. These findings serve as a crucial stepping stone, offering valuable insights into the potential of ferrous bisglycinate as a solution to the global challenge of iron deficiency and anaemia.

References

Miller JL. Iron deficiency anemia: a common and curable disease. Cold Spring Harb Perspect Med. 2013 Jul 1;3(7):a011866. doi: 10.1101/cshperspect.a011866. PMID: 23613366; PMCID: PMC3685880.