Vitamin D receptor gene polymorphism in patients with osteomalacic myopathy in Egypt

The relationship between vitamin D receptor gene polymorphisms and ankylosing spondylitis: a systematic review, meta-analysis and trial sequential analysis

The relation between vitamin D receptor (VDR) gene polymorphisms and ankylosing spondylitis (AS) remains unclear. A systematic review and meta-analysis were conducted using six databases, including PubMed, Web of Science, EMBASE, CNKI, Wanfang and Cochrane Library. The selection of each study was based on inclusion and exclusion criteria. The Newcastle-Ottawa Scale was applied to assess the quality of the included studies, while the strength was evaluated by odds ratios and 95% confidence intervals. The following contrasts were used: allele contrast (H vs h), homozygous contrast (HH vs hh), heterozygous contrast (Hh vs hh), dominant contrast (HH + Hh vs hh) and recessive contrast (HH vs Hh + hh). For the BsmI-rs1544410 polymorphism, three studies were included of 782 cases and 863 controls. The data showed a significant relationship under allele contrast H vs h (OR = 1.66, 95% CI 1.20-2.30 (P = 0.002)). For the TaqI-rs731236 polymorphism, 675 cases and 697 controls were included in two studies. The data showed a significant relationship under allele contrast H vs h (OR = 1.57, 95% CI 1.11-2.21 (P < 0.05)), homozygous contrast Hh vs hh (OR = 1.65, 95% CI 1.12-2.43 (P < 0.05)), and recessive contrast HH + Hh vs hh (OR = 1.66, 95% CI 1.13-2.43 (P < 0.05)). There were significant relationships between VDR gene BsmI-rs1544410 and TaqI-rs731236 polymorphisms and AS, while no associations were found between FokI-rs2228570 and ApaI-rs7975232 polymorphisms and AS. In the future, additional studies with larger case numbers are need.

Is it reasonable to ignore vitamin D status for musculoskeletal health?

Severe vitamin D deficiency—25-hydroxyvitamin D (25OHD) concentrations below around 25–30 nmol/L—may lead to growth plate disorganization and mineralization abnormalities in children (rickets) and mineralization defects throughout the skeleton (osteomalacia) and proximal muscle weakness. Both problems are reversed with vitamin D treatment. Apart from this musculoskeletal dysfunction at very low vitamin D levels, there is apparent inconsistency in the available data about whether concentrations of 25OHD below around 50 nmol/L cause muscle function impairment and increase the risk of fracture. This narrative review provides evidence to support the contention that improving vitamin D status, up to around 50 nmol/L, plays a small causal role in optimizing bone and muscle function as well as reducing overall mortality.