# Folate and Vitamin B12 Status in Pediatric Hematopoietic Stem Cell Transplantation Patients

## TL;DR

This study examines how vitamin B12 and folate levels change in children before and after hematopoietic stem cell transplantation, highlighting the need for close monitoring and supplementation.

## Contribution

The study provides empirical evidence on the fluctuation of B12 and folate levels in pediatric HSCT patients and emphasizes the importance of early supplementation.

## Key findings

- B12 levels significantly increased one month after transplantation but decreased by six months.
- Folate levels were significantly lower one month post-transplantation compared to pre-transplant and six months post-transplant.
- Despite treatment, deficiencies in B12 and folate were observed, indicating increased nutritional demands.

## Abstract

Background/Objectives: Vitamin B12 and folic acid (FA) are crucial for children’s hematopoiesis after hematopoietic stem cell transplantation (HSCT). This study evaluates the B12 and FA level changes before and after HSCT. Methods: We retrospectively collected data from 125 patients who underwent HSCT between March 2019 and February 2024. B12 and FA levels were measured at three time points: before transplantation, one month after, and six months after. Sixty-two patients had complete data. B12 deficiency was defined as levels < 200 pg/mL and insufficiency as 200–300 pg/mL. Folate deficiency was classified as insufficiency ≤ 3 ng/mL, indeterminate for 4.0–5.8 ng/mL and typical for 5.9–26.8 ng/mL. Patients with B12 < 300 pg/mL and folic acid < 5 ng/mL were treated at all stages. Results: Among the 62 patients, 24 (38.7%) were girls, with a median age of 4 years (1.75–8.25). Median B12 levels were 398 pg/mL (pre-transplant), 892 pg/mL (1 month post), and 430 pg/mL (6 months post). The second time point had significantly higher B12 levels (p < 0.001). Median folate levels were 9.7 ng/mL, 6.95 ng/mL, and 11.3 ng/mL at the respective time points (p < 0.05), with the second time point significantly lower. Conclusions: Pediatric HSCT patients experience increased demands for B12 and FA despite accurate treatment, leading to potential deficiencies. Close monitoring, early supplementation, and supplementing high levels of these micronutrients are essential.