Study Finds High Prevalence of Vitamin B12 Deficiency in Stem Cell Transplant Recipients

Led by Ewa Karakulska-Prystupiuk, the research team analyzed data from 341 transplant recipients treated between 2014 and 2023. They recorded the lowest levels of vitamin B12 and folate detected during the two-year period post-transplant, using deficiency levels established in NHANES population surveys. The findings were concerning: 49% of patients exhibited vitamin B12 levels below 300 pg/mL, with 17% below 200 pg/mL, while 46% of patients showed folate deficiency, defined as levels under 3 ng/mL.

Graft-versus-host disease occurs when the donor's immune cells attack the recipient's tissues, with gastrointestinal involvement causing significant nutrient absorption issues. The study postulates that mucosal injury from cGVHD, combined with lower dietary intake and the impacts of immunosuppressive medications, leads to vitamin deficiencies, particularly affecting B12 and folate, which rely on the gut for absorption.

Among a subgroup of 68 patients with confirmed gastrointestinal cGVHD, the results were stark. These patients had a median vitamin B12 level of 258 pg/mL compared to 442 pg/mL in those without gastrointestinal issues. Additionally, 88.6% of the gastrointestinal group were classified as deficient, versus only 11.4% in the non-gastrointestinal group, a statistically significant difference (p < 0.001).

The study also found a correlation between the severity of gastrointestinal cGVHD and B12 levels, with reduced nutrient absorption worsening as gut damage increased. Although folate levels were similarly lower in the gastrointestinal cohort, the difference was not statistically significant, potentially due to the nutrient’s varied absorption sites in the intestine.

Analyzing the prevalence of anemia, a common post-transplant issue, the study recorded significantly lower hemoglobin levels in patients with gastrointestinal cGVHD (12.2 g/dL) versus those without (13.25 g/dL), with a p value of 0.006. Surprisingly, the anemia did not directly correlate with vitamin deficiencies, indicating that multiple factors contribute to post-transplant anemia.

The authors stress the importance of monitoring vitamin B12 and folate levels regularly, especially for patients with gastrointestinal chronic graft-versus-host disease, given that untreated deficiencies can lead to neurological damage and increased fatigue. They suggest that a proactive approach to supplementation should be considered even in the absence of anemia, although whether this should be expanded to all transplant recipients remains uncertain.

While the study's design as a single-center retrospective analysis does have limitations, its findings call for increased attention to micronutrient status in transplant recipients, aiming to improve long-term health outcomes as survival rates improve.