Vitamin B₁₂ Deficiency in Jordan: A Population-Based Study

Abstract

Background: Vitamin B₁₂ deficiency is highly prevalent worldwide and has been linked to hematologic, neurologic and psychiatric diseases. There are a few studies regarding vitamin B₁₂ deficiency in developing countries in general and in Jordan in particular. Objectives: The aims of the present study were to assess the vitamin B₁₂ status of Jordanians at national level and to identify population groups at high risk for vitamin B₁₂ deficiency. Methods: Vitamin B₁₂ status was assessed in a national sample of 5,640 subjects aged >8 years. The study involved interviews, laboratory measurements of vitamin B₁₂ and other parameters, and physical measurements. The present report deals exclusively with subjects aged >18 years (n = 2,847). Results: The percentages of subjects with low (<200 pg/ml, n = 857), borderline (201-350 pg/ml, n = 382) and normal vitamin B₁₂ level (>350 pg/ml, n = 1,608) were 30.1, 13.4 and 56.5%, respectively. Of the 382 subjects who had borderline vitamin B₁₂ level, 61 subjects had both increased total homocysteine (tHcy; >13 µmol/l) and low holocobalamin (<35 pmol/l). Since elevated tHcy also indicates folate deficiency, the overall prevalence of vitamin B₁₂ deficiency reached 32.2% (31.9% among males and 32.4% among females) after adding those 61 subjects to the 857 subjects with low vitamin B₁₂ level. Conclusion: In conclusion, our study showed that almost one third of Jordanian adults have vitamin B₁₂ deficiency with no gender differences. Intake of vitamin B complex and multivitamins seems to protect from vitamin B₁₂ deficiency. An in-depth study of the dietary and eating habits of Jordanians may be needed to explain the observed age and regional differences in vitamin B₁₂ deficiency in the study population.

Vitamin B12 Deficiency and the Role of Gender: A Cross-Sectional Study of a Large Cohort

“…The study revealed that gender plays a role in vitamin B12 metabolism, with a twofold greater risk for deficiency among men, independent of anemia, folate, and homocysteine status. Although the prevalence is similar to the level reported in a neighboring Middle Eastern country, the gender differences are surprising [19]. …”

Status of Vitamin B12 and Folate among the Urban Adult Population in South India

“…Even amongst the vegetarians and mixed diet group, the B12 deficiency was higher in men than in women (70 vs. 43% and 38 vs. 24%) despite the higher dietary intake in men. However, it should be noted that the concentration of B12 between 203 and 350 pg/ml [37,38] accompanied by elevated plasma Hcys concentration (>12 μmol/l) was considered as borderline deficiency of B12. Therefore, we have also analyzed the concentration of Hcys in the samples to confirm borderline deficiency of B12.…”

Reference Range Estimation: Accounting for Measurement System Errors

“…A reference range of 200 to 900 picogram (pg) per milliliter (ml) is commonly used for vitamin B12 concentration in the blood . Adults with lower B12 level than the lower limit of 200 pg/ml are considered B12 deficient.…”

“…Based on these different reference ranges, recent studies revealed a prevalence of 16 to 50% B12 deficiency among Jordanians . In their most recent study, report that one‐third of jordanians are B12 deficient based on a 200 pg/ml lower limit. An urgent question to be answered is the following: what is the true reference range for normal B12 level?.…”

“…3,4 A reference range of 200 to 900 picogram (pg) per milliliter (ml) is commonly used for vitamin B12 concentration in the blood. 5 Adults with lower B12 level than the lower limit of 200 pg/ml are considered B12 deficient. Patients with B12 deficiency suffer from anemia because of the reduced number of red blood cells produced.…”