Vitamin D May Play Key Role in Anemia Prevention, Study Finds

Elevated serum 25-hydroxyvitamin D [25(OH)D] levels independently reduced the risk of anemia in a new analysis, suggesting the physiologically active form of vitamin D may be a causative protective factor against the blood disorder.¹

“These findings, which suggest that regulating 25(OH)D levels through supplementation or lifestyle modifications may be a useful tactic for reducing the prevalence of anemia, especially in susceptible populations, have significant therapeutic ramifications,” wrote the investigative team, led by Chunyan Wang, department of geriatrics, The Second Hospital, Cheelo College of Medicine, Shandong University.

Anemia, a significant global public health issue, is characterized by hemoglobin or erythrocyte levels falling below typical age- and sex-adjusted ranges.² World Health Organization (WHO) estimates indicate nearly 1.6 billion people exhibit anemia to varied degrees, with region, age, gender, and socioeconomic status influencing the specific incidence.

Recent literature has investigated the involvement of 25(OH)D in anemia development, as several studies have reported its positive effect by inhibitory actions on hepcidin and inflammatory cytokines.³ A cross-sectional using the National Health and Nutrition Examination Survey (NHANES) between 2001 and 2018 found a correlation between anemia incidence and serum 25(OH)D concentration.⁴

However, as the precise mechanisms remain unknown, Wang and colleagues sought to clarify the potential causative effect between 25(OH)D levels and anemia incidence.

“By means of thorough scientific investigation, we want to offer a more refined comprehension of the complex elements that cause anemia, opening the door to better public health results and higher standards of living,” they wrote.

Employing two-sample bidirectional Mendelian randomization and cross-sectional research methods, the team evaluated a local database of 7160 hospitalized patients in China from January 2021 to June 2023. Patients were primarily female (51.6%) and the average age was 56.5 years—the prevalence of anemia was 24.3%.

Patients were categorized into cohorts based on 25(OH)D concentrations: ≥75 nmol/L for the sufficient group, 50–75 nmol/L for the insufficient group, 25–50 nmol/L for the deficient group, and ≤25 nmol/L for the severe deficiency group.

Serum 25(OH)D concentration and anemia risk were significantly inversely correlated after multivariable logistic regression analysis. A model, fully adjusted for demographics, comorbidities, and laboratory test findings, revealed the risk of anemia decreased by 5% for every unit increase in 25(OH)D levels (odds ratio [OR], 0.95; 95% CI, 0.94–0.97; P <.001).

After accounting for all variables, Wang and colleagues identified a nonlinear dose-response association between the risk of anemia and 25(OH)D concentration. The 25(OH)D concentration threshold was 48.716 nmol/L.

The two-sample Mendelian randomization analysis confirmed a protective casual association between 25(OH)D concentration and reduced anemia incidence, with each standard deviation increase in 25(OH)D linked to a 5% decreased incidence in anemia. On the other hand, bidirectional Mendelian randomization analysis found no evidence that anemia impacts 25(OH)D concentration.

“The results provide new insight into the field of anemia and iron deficiency etiology,” Wang and colleagues added. “The results add meaningful contribution to the field by providing the link between anemia and serum 25(OH)D.”

References

1. _{Bi S, Zhang J, Wei N, Zhou Q, Wang C. Association Between Serum 25-Hydroxyvitamin D Level and Risk of Anemia: An Observational and Mendelian Randomization Study. Int J Gen Med. 2024;17:3893-3905. Published 2024 Sep 6. doi:10.2147/IJGM.S479039}
2. _{McLean E, Cogswell M, Egli I, Wojdyla D, de Benoist B. Worldwide prevalence of anaemia, WHO Vitamin and Mineral Nutrition Information System, 1993-2005. Public Health Nutr. 2009;12(4):444-454. doi:10.1017/S1368980008002401}
3. _{Smith EM, Tangpricha V. Vitamin D and anemia: insights into an emerging association. Curr Opin Endocrinol Diabetes Obes. 2015;22(6):432-438. doi:10.1097/MED.0000000000000199}
4. _{Zhang Y, Wang X, Wang J, et al. The Association between Standardized Serum 25-Hydroxyvitamin D Concentration and Risk of Anemia: A Population-Based Cross-Sectional Study. Int J Clin Pract. 2022;2022:8384306. Published 2022 Oct 13. doi:10.1155/2022/8384306}