SummaryBackgroundVitamin B12 (cobalamin) deficiency is a prevalent worldwide health concern. Several factors are associated with vitamin B12 deficiency including lifestyle, genetic predisposition, and malfunctions in the absorption and transport of vitamin B12. In the current case-control study, we aimed at investigating the association between MTHFR polymorphisms and vitamin B12 deficiency in a Jordanian population.MethodsTwo polymorphic sites of the MTHFR gene (c.677C>T, rs1801133 and c.1286A>C, rs1801131) were analyzed using RFLP and DNA sequencing in a group of vitamin B12 deficient individuals (45 males and 55 females). As a control, 100 matching individuals (age and sex) with vitamin B12 levels > 200 ng/mL were also recruited for this study.ResultsThe MTHFR c.677C>T variant was significantly associated with vitamin B12 deficiency in individuals from northern Jordan. The frequency of the homozygous MTHFR c.677C>T genotype was significantly higher in B12 deficient individuals in comparison with the control group (X2 = 8.397, p = 0.0150). The T allele frequency showed significant association with vitamin B12 deficiency in the study population (OR= 1.684, 95% CI: 1.116 to 2.542, p = 0.017). On the other hand, the MTHFR c.1286A>C variant did not show significant association with vitamin B12 deficiency in the selected population.ConclusionsOur results showed a significant association between homozygous MTHFR c.677C>T variant and T allele frequencies and vitamin B12 deficiency in the Jordanian population.

Vitamin B12, folate, and ferritin are vital for the development of the nervous system, blood formation, and diverse metabolic functions. The aim of the current study is to evaluate the status of vitamin B12, folate and ferritin in the Jordanian population across distinct geographical locations. In this retrospective study, the cohort population included 2,880 Jordanian individuals with an average age of 47 y for males and 34 y for females (January 2014-December 2016). Vitamin B12, folate, and ferritin were measured in the blood samples by immunoassay on an automated instrument. Prevalence of low levels of vitamin B12 among males and females was similar across the four regions (24%). Equivalently high levels of folate were reported in males (24.4%) and females (23.4%). Additionally, 37.4% of males and 20.4% of females showed low levels of ferritin. Pearson's correlations did not show any association between age, vitamin B12, folate, and ferritin levels in both sexes. Univariate odd ratio (OR) and age-adjusted OR in males showed a significant decrease in low vitamin B12 risk in the region of Tafela when compared to Irbid. In conclusion, our results showed a significant difference in vitamin B12 levels between populations according to their geographical locations. Ferritin levels were low in almost a quarter of the Jordanian population with a high prevalence in males and females in Irbid and Maan, respectively. These differences might be associated with the genetic, dietary and lifestyle situation which requires further studies to elucidate the risk factors for vitamin B12 and ferritin deficiency. Key Words cobalamin, geographical location, micronutrients, folic acid, iron deficiency Cobalamin (Vitamin B12) is an essential vitamin for the synthesis of methionine, DNA, red blood cells and the myelin of the nerve cells (1-3). Therefore, it is crucial to be obtained from natural sources such as meat, milk, and eggs (4). Naturally, vitamin B12 deficiency is caused by malnutrition, malabsorption or genetic predisposition and it takes up to 5 y to develop (5-7). Vitamin B12 deficiency can lead to serious pathology including megaloblastic anemia and certain neurological disorders (8-12). Moreover, vitamin B12 is required for the metabolism of folic acid. In Jordan, vitamin B12 deficiency is a serious health concern. However, few studies have evaluated the level of vitamin B12 in the Jordanian population with different prevalence (13-17). Many factors have been proposed to be associated with the deficiency of vitamin B12 including genetic predisposition, lifestyle, environment, socioeconomic status and geography (17-19). For instance, certain polymorphisms in the gastric intrinsic factor, MTHFR, and transcobalamins have been found to be related to the level of vitamin B12 (20-23). Furthermore, in an interesting Chilean study, Cabrera et al. reported that the deficiency of vitamin B12 is associated with UV light exposure (19). Geographically, Jordan is a Middle East country, located in Southwest Asia and northern of Tropic o...

Abstract. Vitamin B12 (Cobalamin) deficiency, due to improper internalization of cobalamin, is a metabolic disorder prevalent in impoverished and elderly populations and is associated with megaloblastic anemia and dementia. It has been suggested that mutations in transcobalamin II ( TCN2) or gastric intrinsic factor (GIF) proteins can alter their binding efficiency to cobalamin or reduce the ability of their receptors to internalize them. In this case-control study, the correlation between vitamin B12 deficiency and alternative alleles of TCN2 and GIF was investigated in a Jordanian population. One hundred individuals with vitamin B12 deficiency (B12 < 200 mg/mL) were enrolled in our study to evaluate the TCN2 and GIF polymorphisms. The control group (B12 > 200 mg/mL) included 100 individuals. Our results indicated a significant association between the homologous variant of the TCN2 gene (G776G) and vitamin B12 deficiency, and an intermediate phenotype in heterozygous individuals ( p < 0.001, OR = 5.6, 95% CI = 2.95 to 10.63). The GIF gene, however, showed no correlation between the A68G variant and vitamin B12 deficiency ( p = 0.2). This study expounds the association of TCN2 polymorphism with cobalamin levels in a Jordanian population and highlights the necessity of further studies to elucidate the molecular basis and impact of TCN2 and GIF genes polymorphisms on vitamin B12 deficiency and associated disorders.

This study was conducted at the farm of Sakha Agriculture Research Station during 2011 and 2012 growing seasons using nine parents and 36 hybrid combinations to study the relationship between genetic distances of parental genotypes and heterosis. The genetic distance of parental genotypes was determined by using functional genes markers related to yield traits. The correlation between genetic distance of parental genotypes and heterosis values was detected by determining 36 hybrids performance. The results indicated that the genetic distance was significant and positive correlated with grain yield/plant for midparent and standard heterosis estimates of r=0.46* and r=0.35*, respectively. While the parental genetic distance was not significant correlated with heterosis for some other traits among them: number of productive panicles/plant, 1000-grain weight, fertility percentage% and number of grains/panicle. Thus, the correlation coefficients was not sufficient enough among the parental genotypes for these traits and was not suitable to use molecular potentiality for heterosis prediction.

2010 summer seasons to investigate the effect of irrigation intervals,3-days "T1",6days "T2" and 9-days "T3" on three rice cultivars; namely, Giza 177, "V1", Giza 178 "V2" and Sakha 104 "V3" with Algalization (cyanobacteria) rates; namely, control (without Algalization, C0), 1000 g/fed "C1" and 1500 g/fed "C2 ". The data showed that Giza 178 gave the highest values, while, Giza 177 had the lowest for plant height, number of tillers/m 2 and number of roots/hill. Also, Giza 177 had the superiority over the other two cultivars in grain yield and water utilization. This efficiency could be attributed to its higher number of filled grains/panicle, sterility(%) and 1000grain weight. On the other side, the gel consistency and gelatinization temperature of all rice cultivars were soft and low, respectively. Data clarified that increasing irrigation intervals decreased plant height, number of tillers/m2 DMA, panicles length, number of panicles/ m 2 , number of filled gains/panicle, 1000-grain weight and grain yield. However, the opposite was true for sterility percentage and W UE. In addition, rice quality was not significantly affected by irrigation intervals. All growth characters were significantly increased due to Algalization compared to the nonalgalized plots. Also, grain yield, grain yield components, WUE and rice quality were significantly increased due to algalization, compared to the non-algalized plots. Generally, it could be concluded that, from the study, rice might be irrigated every six days and save water without deleterious effects, on its production, under Algalization with cyanobacteria with the rate ranged from 1000 to 1500 g/fed.