Association of Serum Ferritin and Vitamin D Levels with Severity of Iron Deficiency Anaemia and Response to Oral Ferrous Sulfate Therapy in Pregnant Women

Abstract

Background: Iron deficiency anaemia is the most prevalent nutritional problem in pregnancy and can have negative effects on maternal health and pregnancy outcomes. Serum ferritin, a marker of iron stores is highly used and iron deficiency is now seen to be linked with a disturbed erythropoiesis and iron metabolism.The other factor is serum ferritin, which is a marker of iron stores, and vitamin D deficiency has been linked with altered iron metabolism and disturbed erythropoiesis. The understanding of the relationship between these biomarkers and response to oral iron therapy may help to enhance the management of anaemia during pregnancy.

Objective: To determine the association of serum ferritin and vitamin D levels with the severity of iron deficiency anaemia and response to oral ferrous sulfate therapy in pregnant women.

Methodology: This is a prospective, observational study at Bacha Khan Medical College, Mardan, from January 2025 to June 2025. In total 75 iron deficiency anaemic pregnant women were enrolled. Hb, haematological indices, serum ferritin and serum 25-hydroxyvitamin D levels were determined. Anaemia was classified into mild, moderate and severe. Oral ferrous sulfate therapy was administered to all participants and a re-evaluation was made after the treatment period. Increase in Haemoglobin of 1.0 g/dL or more was regarded as satisfactory response. P<0.05 was considered statistically significant.

Results: The mean age of participants was 27.81 ± 4.63 years, and the mean baseline haemoglobin level was 9.21 ± 1.12 g/dL. Mean serum ferritin and vitamin D levels were 12.84 ± 6.71 ng/mL and 19.76 ± 8.39 ng/mL, respectively. Serum ferritin decreased significantly from 17.62 ± 6.14 ng/mL in mild anaemia to 5.46 ± 2.73 ng/mL in severe anaemia, while vitamin D decreased from 24.83 ± 8.11 ng/mL to 12.98 ± 5.44 ng/mL (both p<0.001). After oral ferrous sulfate therapy, mean haemoglobin increased to 10.87 ± 1.09 g/dL (p<0.001). Overall, 78.7% of women achieved a satisfactory treatment response. Responders had significantly higher baseline ferritin and vitamin D levels than non-responders.

Conclusion: Lower serum ferritin and vitamin D concentrations were significantly associated with greater severity of iron deficiency anaemia in pregnancy. Higher baseline levels of both biomarkers were also associated with a better haematological response to oral ferrous sulfate therapy. Assessment of vitamin D status alongside conventional iron parameters may provide additional information for the clinical evaluation and management of pregnant women with iron deficiency anaemia.