Bone Mineral Density and Vitamin D Receptor Genetic Variants in Egyptian Children With Beta Thalassemia on Vitamin D Supplementation

Abstract

BackgroundLow bone mineral density (BMD) is a characteristic feature of Beta thalassemia major (βTM) patients. Vitamin D is important for bone mineralization. Vitamin D receptors (VDR) genetic variants may be related to vitamin D status and BMD.ObjectivesTo evaluate the effect of VDR genetic variants on vitamin D levels and BMD in βTM Egyptian patients supplemented with vitamin D.MethodsThis study was conducted on forty children with βTM and seventeen unrelated healthy sex and age-matched controls. Serum calcium, phosphorus, alkaline phosphatase, ferritin, and vitamin D were measured. VDR genetic variants (BsmI, TaqI, and FokI) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). BMD was measured by dual-energy X-ray densitometry (DEXA) of the lumbar spine.ResultsIn βTM patients, 22.5% had insufficient, and 77.5% had sufficient levels of vitamin D, and no cases had vitamin D deficient. BMD Z score was significantly lower in βTM patients compared to controls (p<0.001). Osteopenia and osteoporosis of lumbar spines were observed in 70% and 22.5% of βTM patients respectively. BsmI bb and FokI Ff and ff genotypic variants were significantly associated with lower vitamin D and BMD Z score. No association was observed with TaqI genotypic variants.ConclusionsLow BMD is prevalent in patients with βTM despite vitamin D supplementation. The BsmI bb, FokI Ff and ff genotypic variants of VDR can be considered as risk factors for the occurrence of osteoporosis in these children.

Association of VDBP rs4701 variant, but not VDR/RXR-α over-expression with bone mineral density in pediatric β-Thalassemia patients

“…It is worth noting that our findings with that of Abbassy et al, 27 who found associations of some VDR genetic variants (i.e., BsmI bb, FokI Ff, and ff) with BMD changes and occurrence of osteoporosis in the same type of population, confirm and support vitamin D metabolic-axis genetic variants implication in BMD of pediatric Egyptian β-thalassemia patients.…”

The impact of vitamin D supplementation on VDR gene expression and body composition in monozygotic twins: randomized controlled trial

“…Vitamin D is involved in several non-skeletal functions, such as cell regulation, differentiation, and growth 3 , and adaptive and innate immunity control 5 , as well as being associated with inflammatory markers 6 , since the vitamin D receptor ( VDR ) is expressed in almost all human cells 7 . The activity of this nutrient in the human organism involves its binding with VDR 8 , whose expression is modulated by the blood levels of the 1,25diidroxi-vitamin D (1,25 (OH) 2D) 9 and genetic variants 10 .…”

Vitamin and Mineral Supplementation for β-Thalassemia During COVID-19 Pandemic

“…The immune-related vitamins and minerals, including vitamin C [ 9 ], vitamin E [ 9 , 14 ], vitamin D [ 15 ], zinc [ 9 , 16 ] and selenium [ 9 , 17 ], were identified to be reduced among patients with β-thalassemia when compared with healthy controls. Only one study by El Missiry et al reported normal levels of zinc among 30 patients, which was comparable with healthy control [ 18 ].…”

“…Only one study by El Missiry et al reported normal levels of zinc among 30 patients, which was comparable with healthy control [ 18 ]. Interestingly, the mean level of 25-OHD 3 in β-thalassemia and healthy controls was lower than the sufficient reference value [ 15 ]. A similar finding was observed regarding selenium [ 9 , 17 ] and in zinc [ 16 ] indicating that these reduced vitamins and minerals might not only be affected by the disease status or severity.…”

“…A study in Egypt involved 40 patients with β-thalassemia and 17 healthy controls showed the mean serum level of 25-OHD of all respondents was below >30 ng/ml. Nine of 40 patients (22.5%) presented vitamin D deficiency [ 15 ]. The risk for developing vitamin D deficiency among patients with thalassemia includes liver iron deposition, darker skin, inadequate dietary and supplement intake, less sun exposure or less physical activity due to the disease burden [ 61 ].…”