Vitamin D Influence on Anemia and Iron Metabolism

Vitamin D, beyond its classical role in bone health, exerts multifaceted effects on erythropoiesis and iron homeostasis. Its active metabolite, 1,25‐dihydroxyvitamin D, downregulates hepcidin synthesis in hepatocytes, thereby enhancing ferroportin-mediated iron export from enterocytes and macrophages. By attenuating pro-inflammatory cytokine release, vitamin D mitigates anaemia of chronic disease and supports iron mobilisation. Deficiency in 25-hydroxyvitamin D is linked to lower haemoglobin levels, higher inflammatory markers and reduced transferrin saturation across diverse populations. Emerging evidence suggests both absolute and functional iron deficiency may be downstream of suboptimal vitamin D status. Clinical and mechanistic studies highlight a bidirectional relationship in which iron availability influences vitamin D metabolism and vice versa. Understanding this interplay is critical for addressing global burdens of anaemia and tailoring nutritional or pharmacological interventions.

Research from Nature Portfolio

A longitudinal study in paediatric patients with type I diabetes compared those with sufficient vitamin D status to those with deficiency. Children with low serum 25-hydroxyvitamin D exhibited reduced haemoglobin, elevated red cell distribution width and lower serum iron, ferritin and transferrin levels. Markers of inflammation, including interleukin 6 and C-reactive protein, were significantly higher in the deficient group. Hepcidin concentrations rose as vitamin D status declined, suggesting a mechanistic link to functional iron sequestration. The work indicates that vitamin D deficiency heightens the risk of both absolute and functional iron deficiency anaemia in young individuals with chronic metabolic disease, underscoring the need for vitamin D assessment in anaemia management.

Vitamin D Influence on Anemia and Iron Metabolism publication trend

The graph below shows the total number of articles in vitamin d influence on anemia and iron metabolism across all publications each year (not limited to Nature Index journals).

Technical terms

Hepcidin: A hepatic peptide hormone that inhibits iron export by binding to ferroportin, reducing intestinal absorption and macrophage iron release.

25-Hydroxyvitamin D (25(OH)D): The principal circulating form of vitamin D used to assess vitamin D status before activation to 1,25-dihydroxyvitamin D.

Ferritin: An intracellular protein complex that stores iron and releases it in a controlled manner; circulating ferritin reflects total body iron stores.

Transferrin Saturation: The fraction of iron-binding sites on transferrin occupied by iron, indicating the availability of iron for erythropoiesis.

Absolute Iron Deficiency: Depletion of total body iron stores, marked by low ferritin and reduced bone-marrow iron.

Functional Iron Deficiency: Adequate iron stores but impaired mobilisation due to elevated hepcidin or inflammation, leading to reduced iron availability for red cell production.

References

1. Nutritional Modulation of Hepcidin in the Treatment of Various Anemic States. Nutrients (2023).
2. Impact of vitamin D deficiency on iron status in children with type I diabetes. Scientific Reports (2024).
3. Serum Vitamin D Levels and Risk of Iron Deficiency Anemia in Adults: A Cross‐Sectional Study and Mendelian Randomization Analysis. Food Science & Nutrition (2025).
4. The effect of vitamin D supplementation on hemoglobin concentration: a systematic review and meta-analysis. Nutrition Journal (2020).