Association between Vitamin D Deficiency and Vitamin D Receptor Gene Polymorphism (FokI-rs2228570) among Men with Anemia in Babylon Province, Iraq

Vitamin D or calciferol is a fat-soluble vitamin that has a unique feature of synthesizing in the body mainly by exposure to UV from the sunlight and then transformed to 25 (OH) D by the liver and finally to a vital form 1,25-dihydroxyvitamin D by the kidneys. Vitamin D receptor gene polymorphism (FokI-rs2228570) has been proposed as the major cause of anemia. The present study aimed to discover the association between vitamin D deficiency and vitamin D receptor gene polymorphism (FokI-rs2228570) in patients with anemia. A total of 120 men with anemia and no kidney disorders have been compared with 60 healthy controls in the present case-control study. A single nucleotide polymorphism (SNP) FokI-rs2228570 was detected by PCR and PCR-RFLP techniques. Levels of serum vitamin D, erythropoietin, and some biochemical parameters were detected by the ELISA assay technique. The mutant homozygous genotype ff was more frequent in patients with anemia (45%) than in the controls (15%). Also, the frequency of the f allele was associated with a significant decrease in the levels of vitamin D and hemoglobin in patients (0.62%); therefore, the mutant allele is a risk factor for developing anemia compared with genetic patterns FF and Ff. Vitamin D deficiency is common in those with anemia which is often associated with low hemoglobin and high levels of erythropoietin. Additionally, the genetic frequencies also affect the level of vitamin D which is indicated by low levels of mutant patterns (Ff, ff) in which patients suffer from severe anemia.