ABSTRACT
OBJECTIVE: This study aimed to evaluate the effect of vitamin D3 megadose supplementation and influence of BsmI polymorphism in the VDR gene on the inflammatory profile and oxidative stress in elderly women with vitamin D deficiency. METHODS: A double blind, randomized, placebo-controlled trial was conducted with 40 elderly women (aged 68±6 years) diagnosed with vitamin D insufficiency (24.7±3.1 ng/mL). Participants were distributed into a supplementation group that received 200,000 IU of vitamin D3 (SG; n=20) and a placebo group (PG; n=20). Blood samples were collected at baseline and after intervention to analyse the 25(OH)D, parathyroid hormone, serum calcium, ultra-sensitive C-reactive protein (us-CRP), alpha 1-acid glycoprotein (AGP-A), total antioxidant capacity (TAC), and malondialdehyde (MDA) levels, as well as the renal and hepatic function, and genotyping was performed for BsmI polymorphism. RESULTS: Four weeks after supplementation, elderly women in the SG group showed a significant increase in the serum concentration of 25(OH)D (25.29±2.8 to 31.48±6.0; p=0.0001), which was followed by increased TAC (65.25±15.66 to 71.83±10.71; p=0.03) and decreased serum PTH (46.32±13.2 to 35.45±11.0; p=0.009), us-CRP (0.38±0.3 to 0.19±0.1; p=0.007) and AGP-A levels (75.3±15.4 to 61.1±5.9; p=0.005). Changes in BP, ANAC and MDA were not observed. The 25(OH)D and PTH, us-CRP and AGP-A levels of participants with the BB/Bb genotype were more responsive to supplementation, but their other markers did not change. CONCLUSIONS: Supplementation with a vitamin D3 megadose reduced inflammatory markers and increased the total antioxidant capacity in elderly women with vitamin D insufficiency. The 25(OH)D, PTH, us-CRP and AGP-A levels of elderly patients with the BB/Bb genotype were more responsive to supplementation compared with those with the bb genotype.