Frequency of comorbid diseases with high serum Vitamin B12 levels in patients attending King Salman Medical City (KSAMC), at Madinah.

Objectives: Vitamin B12 (Cobalamin or Cbl) plays a crucial role in normal human growth and development, as well as in neurological, cardiovascular, and immune systems. Previous studies reported association of high levels of cobalamin with solid cancers, hematological disorders, and liver diseases. Reporting the frequency of comorbid diseases with high serum Vitamin B12 level in patients attending KSAMC at Madinah.

Methods: This is a retrospective, cross-sectional study on data collected during 1 year (May 2022-May 2023) from 3511 report, patients with high cobalamin blood level (normal upper limit 771 pg/mL) as determined in our laboratory on COBAS were included. Patient's clinical diagnosis, medication history and other laboratory parameters performed were also checked for disease comorbidities.

Results: Our results revealed statistically significant increase in serum Vitamin B12 in patients with diabetes mellitus, with the use of this vitamin as supplement therapy 53.2% (the predominant comorbidity), together with liver, blood, chest, kidney, thyroid and neurological diseases, and various solid tumors. A positive correlation was found between serum Vitamin B12, age and laboratory parameters including aspartate aminotransferase, gamma-glutamyl transferase, and direct bilirubin, and a negative correlation was seen between serum Vitamin B12 level, serum albumin (ALB), red blood cell count, hemoglobin, and free T3 (FT3). While, no significant correlation with the rest of the checked parameters was detected.

Conclusion: This study found high serum level of Vitamin B12 associated with various disease entities, for example, (diabetes mellitus treated with Vitamin B12 as supplement therapy, liver, blood, chest, kidney, thyroid, neurological diseases, and various solid tumors), so when Vitamin B12 is high, further investigations will be recommended. Most of the comorbidities were benign in Saudis, followed by Egyptians with predominance of female-aged 50-70 year old.