Iron-Containing Oral Contraceptives and Their Effect on Hemoglobin and Biomarkers of Iron Status: A Narrative Review

Nutrients. 2021 Jul 9;13(7):2340. doi: 10.3390/nu13072340.

Abstract

Oral contraceptive use has been associated with decreased menstrual blood losses; thus, can independently reduce the risk of anemia and iron deficiency in women. Manufacturers have recently started to include supplemental iron in the non-hormonal placebo tablets of some contraceptives. The aims of this narrative review are: (i) to describe the relationship between oral contraceptive use and both anemia and iron status in women; (ii) to describe the current formulations of iron-containing oral contraceptives (ICOC) available on the market; and (iii) to systematically review the existing literature on the effect of ICOC on biomarkers of anemia and iron status in women. We discovered 21 brands of ICOC, most commonly including 25 mg elemental iron as ferrous fumarate, for seven days, per monthly tablet package. Our search identified one randomized trial evaluating the effectiveness of ICOC use compared to two non-ICOC on increasing hemoglobin (Hb) and iron status biomarker concentrations in women; whereafter 12 months of contraception use, there were no significant differences in Hb concentration nor markers of iron status between the groups. ICOC has the potential to be a cost-effective solution to address both family planning needs and iron deficiency anemia. Yet, more rigorous trials evaluating the effectiveness of ICOC on improving markers of anemia and iron deficiency, as well as investigating the safety of its consumption among iron-replete populations, are warranted.

Keywords: anemia; birth control; contraceptive; ferritin; ferrous iron; hemoglobin; iron; iron deficiency; iron-containing oral contraceptives; oral contraceptive.

Publication types

  • Systematic Review

MeSH terms

  • Adult
  • Anemia, Iron-Deficiency / blood
  • Anemia, Iron-Deficiency / drug therapy
  • Biomarkers / blood
  • Contraceptives, Oral / administration & dosage
  • Contraceptives, Oral / chemistry*
  • Family Planning Services / methods
  • Female
  • Ferrous Compounds / blood*
  • Hemoglobins / drug effects*
  • Humans
  • Iron / administration & dosage*
  • Iron / analysis

Substances

  • Biomarkers
  • Contraceptives, Oral
  • Ferrous Compounds
  • Hemoglobins
  • Iron
  • ferrous fumarate