Lower serum B12 vitamin concentrations are not accompanied by hyperhomocysteinaemia in chronic spontaneous urticaria

Summary Background Lower serum vitamin B12 concentrations have been observed in patients with chronic spontaneous urticaria (CSU). It is known that vitamin B12 deficiency is closely related to hyperhomocysteinaemia, which is associated with a proinflammatory state. Aim To assess the relationship between vitamin B12 status and concentrations of homocysteine (Hcy) with acute phase response in patients with CSU. Methods Circulating concentrations of vitamin B12, Hcy and C‐reactive protein (CRP) were measured in 42 patients with CSU of varying severity, and compared with 19 healthy controls (HCs). Results Significantly lower concentrations of vitamin B12 and higher concentrations of CRP were observed in the serum of the patients with CSU compared with HCs (P < 0.01 and P < 0.001, respectively). However, there were no significant differences in plasma Hcy concentrations between the investigated groups. In addition, no correlations were found between the concentrations of vitamin B12, Hcy and CRP. Conclusions Lower values of vitamin B12 concentration in patients with CSU were not associated with higher Hcy concentrations, suggesting that such patients do not have functional vitamin B12 deficiency.