High frequency of suboptimal serum vitamin B12 level in adults in Jordan

OBJECTIVE: To assess the prevalence of functional vitamin B12 deficiency status in an adult Jordanian seemingly healthy population.

METHODS: We carried out this study in the Department of Physiology, Faculty of Medicine, Jordanian University of Science and Technology, Jordan from September 2004 to January 2005. We included a randomly selected sample of 216 healthy adult volunteers (male 124, female 92, aged 19-50 years) from north Jordan. We carried out the measurement of hematological variables by Micros 60-OT Analyzer. We measured the serum vitamin B12 by microparticle enzyme immunoassay and serum folate by ion-capture assay on an AxSYM Analyzer.

RESULTS: We found suboptimal (<222 pg/ml) serum levels of vitamin B12 in 104 (48.1%) (male 64, female 40) subjects. The mean serum vitamin B12 level of male in all volunteers was 238.8 ± 97.3 pg/ml, not significantly different (p=0.24) from that of female (261.8 ± 101.6 pg/ml). The mean serum values of vitamin B12 of male in the suboptimal group (168.3 ± 36.4 pg/ml; range 90-221) were not significantly different from that of female (178.2 ± 27.5 pg/ml; range 113-217) (p=0.31). Of the suboptimal group, 30 subjects (28.8%) had hyper-segmented neutrophils, 38 subjects (36.5%) had low mean corpuscular volume and 8 subjects (7.7%) had sub-optimal serum folate levels.

CONCLUSION: This study revealed that there was a high frequency of suboptimal serum vitamin B12 level, which is an early sign of negative B12 balance.