Effect of vitamin D3 supplementation on 25 OHD plasma levels in the presence of VDR gene polymorphisms / Efecto de la suplementación con vitamina D3 en los niveles plasmáticos de 25 OHD, en presencia de polimorfismos del gen VDR

The objective of this review was to investigate the effect of vitamin D3 supplementation on serum 25-hydroxyvitamin D concentration in individuals with single-nucleotide polymorphisms in the vitamin D receptor gene. The research was conducted on 241 articles found in the PubMed, Scopus, Science Direct, and Cochrane Library databases between November and December 2018. After article screening, three randomized double-blind placebo-controlled clinical trials were identified as eligible for this review. Participants were Australian, Brazilian, and Chinese individuals, who ingested doses of vitamin D3 ranging from 2000 IU to a megadose of 200,000 IU. The presence of the BB/Bb genotype of the BsmI polymorphism and the FokI G allele caused an increase in the serum concentrations of vitamin D after supplementation. Nonetheless, the few studies on this subject are not unanimous in their results. It is possible that differences among populations, sample sizes, doses, and time of supplementation have an impact on data and outcomes.

El objetivo de esta revisión fue investigar el efecto de la suplementación con vitamina D3 sobre la concentración sérica de 25-hidroxivitamina D en individuos con los polimorfismos de un solo nucleótido en el gen del receptor de la vitamina D. La investigación se realizó en 241 artículos encontrados en las bases de datos PubMed, Scopus, Science Direct y Cochrane Library entre noviembre y diciembre de 2018. Después de la selección del artículo, se identificaron tres ensayos clínicos aleatorios, controlados con placebo, doble ciego, como elegibles para esta revisión. Los participantes fueron australianos, brasileños y chinos, quienes ingirieron dosis de vitamina D3 que iban desde las 2000 UI hasta una megadosis de 200,000 UI. La presencia del genotipo BB / Bb del polimorfismo BsmI y el alelo FokI G causó un aumento en las concentraciones séricas de vitamina D después de la suplementación. No obstante, los pocos estudios sobre este tema no son unánimes en sus resultados. Es posible que las diferencias entre poblaciones, tamaños de muestra, dosis y tiempo de suplementación tengan un impacto en los datos y resultados de la investigación.

Association of vitamin D receptor gene BsmI polymorphisms with type 2 diabetic nephropathy / 中华肾脏病杂志

Objective To investigate the association between Bsml polymorphism in vitamin D receptor (VDR) gene and diabetic nephropathy in Chinese Han population. Methods PCR-restriction fragment length polymorphism (PCR-RFLP) was used to test the genotype and allele frequency of Bsml in 304 patients with type 2 diabetes mellitus (DM group) and 100 healthy individuals (NC group).The DM group was further divided into non-diabetic nephropathy group (DN0 group,122 cases),minimal albuminuria group (DN1 group,87 cases),and mass albuminuria group (DN2 group,95 cases).Eighty-three DM patients without nephropathy for over 5 years were L-NDN subgroup,and 64 DM patients with nephropathy occurring within the first year were EDN subgroup. Results Genotype and allele frequency of BsmI polymorphism were significantly different between DM and NC group (x2=7.088,P=0.008;x2=5.865,P=0.015).BB+Bb genotype and B allele frequency were significantly higher in DN2 group than those in NC group (x2=14.287,P=0.000;x2=12.621,P=0.000) and DN0 group (x2=8.063,P=0.005;x2=8.173,P=0.004).BB+Bb genotype and B allele frequency were significantly higher in EDN group than those in L-NDN group (x2=7.228,P=0.007; x2=5.853,P=0.016).DN patients with allele B (BB and Bb genotypes)presented higher urinary albumin excretion rates compared with patients without allele B (bb genotype,P＜0.01).The genotype of BsmI was correlated with DN,and allele B was risk factor of DN occurrence and early onset (OR=2.004; OR=2.394). Conclusion VDR gene BsmI polymorphism is associated with DN,and the patients carrying allele B are more involved in mass albuminuria and eady onset of nephropathy.