Discussion
In the Middle East, different countries have reported a high prevalence of vitamin B12 deficiency that is resulted in pernicious anemia [94]. Similarly, the deficiency of vitamin B12 in Jordan is a health concern that needs to be considered seriously. Previous studies showed differences in the prevalence of vitamin B12 deficiency in Jordan. For instance, in a study that included two different populations, the researchers reported 50.8% of vitamin B12 deficiency among the Arab population and 46.9% among Circassians62. Other studies reported 10% 58, 24%57, 27%63, 30%16 and 44.6%64 of vitamin B12 deficiency. The variation in the prevalence can be attributed to the differences between the study populations and age groups16,57-61.
In a recent study, it was shown that vitamin B12 deficiency varies in different provinces of Jordan; Irbid, Karak, Tafilah, and Ma′an57. In this retrospective study, we evaluated vitamin B12 levels in a Jordanian population in Aqaba city and correlated it with gender, age, and CBC parameters. The current study reported a 24.6 % vitamin B12 deficiency in the Aqaba province population. These findings support our previous report detailing the trend of vitamin B12 deficiency according to the geographical location in Jordan. Additionally, the results reported a significant difference between the means of vitamin B12 levels in males and females, 307.59 ±90.75, 265.09 ±106.35, respectively (p = 0.002). In particular, females showed a higher frequency of vitamin B12 deficiency (29%) compared to the male group (14%). Inconsistently with a previous study, the researchers showed that males had a higher frequency of vitamin B12 deficiency than females in Arab and Caucasian populations 62. However, there is some evidence that females have a higher frequency of vitamin B12 deficiency than males65. On the contrary, another study revealed a higher percentage of vitamin B12 deficiency in males (15.2%) compared to females (11.5%)66. Nevertheless, different findings have reported a lack of relationship between gender and vitamin B12 level60. Therefore, other risk factors have to be considered in addition to gender, such as genetic predisposition, and physiological differences, and pregnancy frequency.
The current findings did not report a difference in the vitamin B12 deficiency between age groups, < 40 years and > 40 years (P =0.119), which is consistent with the results of a previous study 62. On the other hand, most studies showed a significant association between vitamin B12 deficiency and age54,63,67,68. In another previous survey that evaluated vitamin B12 deficiency in Jordan for participants whose ages ranged between 19 and 90, the study concluded that mean serum vitamin B12 levels rise with age, however, individuals aged < 40 years had the lowest vitamin B12 levels among all ages, which is consistent with our findings16. Nevertheless, the deficiency of vitamin B12 may commonly affect the elderly. Therefore, the lack of association between the age group and vitamin B12 deficiency can be attributed to the size of the study population from each group.
Herein, the level of vitamin B12 showed a significant association with the level of Hb (P = 0.044). On the contrary, Qutob et al have shown that there was no correlation between B12 status and Hb (p=0.545)63. Additionally, we observed a statistically significant positive correlation between RBCs count and vitamin B12 level (r= 0.354, p=0.001). Metabolically, vitamin B12 is an essential cofactor that results in normal blood cell maturation. Macrocytosis is a cause of ineffective erythropoiesis due to vitamin B12 or folate deficiency69-72. Therefore, our results support the role of vitamin B12 in the erythropoietic process. Moreover, PCV and platelet count showed a significant association with the vitamin B12 level in the studied population. On the other hand, our findings did not show any significant association between the level of vitamin B12 and the MCV. On the contrary, many studies confirmed the inverse relation between B12 level and MCV63,73,74. An elevated MCV refers to the average red blood cell volume that may arise with or without reduced hemoglobin levels65. Overall, Pernicious anemia leads to B12 deficiency and results in producing abnormal and unhealthy RBCs, which means fewer functional erythrocytes75-77.
The current study also aimed to complete the portrait of the prevalence of B12 deficiency in Jordan. In a previous study, we evaluated the prevalence of vitamin B12 deficiency in several regions, starting from the northern part of Jordan, Irbid (41%), Karak (35%), Tafilah (27%) and Ma′an (26%) where we moved in a southerly direction57. Here, we reached the most southern part of Jordan, Aqaba which reported 24.6% vitamin B12 deficiency. This study confirms the association between the geographical location and the frequency of vitamin B12 deficiency in Jordan 57. Fora and Mohammed reported similar observations in the north of Jordan (48%), where their study emphasized high B12 deficiency in northern regions61. Moreover, southern regions had reported lower B12 deficiency than central regions (Amman), and Hakooz et al (2006) reported lower rates of B12 in Amman (48.5%)62. However, the current results showed a similar mean level of vitamin B12 in Aqaba’s population compared to the Irbid’s population and lower level of vitamin B12 compared to the other parts of Jordan (Middle-South). Overall, the current study showed that the deficiency of vitamin B12 in Aqaba is lower than in other parts of Jordan.