Vitamin B12 Deficiency Among the Healthy Jordanian Adult Population: Diagnostic Levels, Symptomology and Risk Factors

Background: Compared to the data available for developed countries, there is a marked scarcity of information on the levels and symptomology of vitamin B-12 deficiency in developing countries, particularly in the Middle Eastern region. Objective: To explore (a) the risk factors associated with a deficiency of vitamin B-12, and (b) the baseline (cut-off) serum level of vitamin B-12 for a clinically-symptomatic deficiency in the Jordanian adult population. Methods: A total of 485 subjects were included in this study. Blood samples were drawn for biochemical analysis and data regarding socio-demographics, general health, anthropometric measures, and past medical, surgical, and medication history were collected. To explore the cut-off point, we compared all parameters included in a standard complete blood count as well as the main symptoms reported to be associated with B-12 deficiency between groups of different B-12 cut-off values, consisting of those above and below 200, 175, 150 and 125 pg/ml. Results: Low dairy intake habits, age, recurrent headaches, heartburn, and peptic ulcer disease were found to be significantly associated with lower vitamin B-12 levels. Surprisingly, daily smoking was associated with significantly higher B-12 levels. The results revealed that none of the included potential indicators of B-12 deficiency could be considered an indicative feature of deficiency. There were no significant differences neither in the symptoms nor in the CBC parameters between any of the tested study groups. Conclusion: Low dairy intake, older ages, recurrent headaches, heartburn, and peptic ulcer disease all could be considered as risk factors of having low vitamin B-12 levels within the Jordanians. Also, they tend to have lower levels of vitamin B-12 levels, in comparison to countries in the West, without necessarily having deficiency symptoms. The cut-off value to diagnose functional B-12 deficiency could be less than 125 pg/ml for the Jordanians. More local studies are needed to establish an accurate vitamin B-12 cut-off value for the population in Jordan.