# Severe Pancytopenia Secondary to Combined Vitamin B12 and Folate Deficiency Mimicking Bone Marrow Failure: A Case Report

## TL;DR

A 65-year-old woman's severe blood cell deficiency was caused by a rare combined vitamin B12 and folate deficiency, not bone marrow failure.

## Contribution

This case highlights the importance of considering nutritional deficiencies in diagnosing pancytopenia in older adults.

## Key findings

- Severe combined vitamin B12 and folate deficiency can mimic bone marrow failure with pancytopenia and jaundice.
- Prompt vitamin replacement led to complete recovery in the patient.
- Nutritional deficiencies remain prevalent among older adults in the UK, causing significant health issues.

## Abstract

Vitamin B12 and folate are essential cofactors for DNA synthesis and red cell maturation. Severe combined deficiency is rare but can mimic bone marrow failure by causing profound pancytopenia and intramedullary haemolysis. This report describes the case of a 65-year-old woman who presented with profound pancytopenia and jaundice caused by severe combined vitamin B12 and folate deficiency. The identification of megaloblastic changes and prompt administration of vitamin replacement led to complete recovery. This case underscores the importance of considering nutritional deficiencies when diagnosing pancytopenia. The report highlights the continued prevalence of such deficiencies among older adults in the United Kingdom and the subsequent associated morbidity.