Abstract

Background: Supplementation of vitamin B12 in older adults is a common practice to avoid vitamin B12 insufficiency. However, there is a paucity of information about the effects of cobalamin excess. Aim: To asses any potential effects of high levels vitamin B12 on mortality on adults aged >= 65 years admitted to an internal medicine service. Material and Methods: We Prospectively studied patients admitted to an internal medicine service of an academic hospital from September 2017 to September 2018, who were able to give their consent and answer questionnaires. We tabulated age, gender, medical history, comorbidity index (Charlson), frailty score (Fried scale), admission diagnosis and blood tests performed within 48 hours of admission. The primary outcome was death by any cause in less of 30 days or after one of year follow up, determined according to death certificates. Results: We included 93 patients aged 65 to 94 years (53% males). Fifteen patients died during the year of follow up (five within 30 days of admission). Those who died had higher cobalamin levels than survivors (1080.07 +/- 788.09 and 656.68 +/- 497.33 pg/mL respectively, p = 0.02). Patients who died had also a significantly lower corrected serum calcium, sodium (p = 0.04) and a medical history of chronic liver disease (p = 0.03). In the multivariable analysis, only vitamin B12 preserved the association with mortality (p = 0.009). Conclusions: There was a significant association between high levels of cobalamin and all-cause mortality in this group of patients aged >= 65 years-old.