Background: This study aimed to identify the impacts of vitamin D and calcium (VitD/Ca) supplementation on bone mineral density (BMD) and bone metabolism among perinatally HIV-infected Thai adolescents.
Methods: An ongoing, randomized open-label trial has been conducted. Adolescents aged 10–20 years who were stable on ART (HIV RNA <400 copies/ml) were randomly assigned to receive either “high-dose”: VitD/Ca (3200 IU/1.2 g daily) or “normal-dose”: VitD/Ca (400 IU/1.2 g daily) supplementation for 48 weeks. Lumbar spine BMD and bone metabolism-related markers were evaluated at baseline and 48 weeks. BMD was measured by dual-energy X-ray absorptiometry, of which z-score ≤−2 was defined as low BMD. Bone metabolism-related markers included 25-hydroxyvitamin D (25OHD), intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), C-terminal telopeptide (CTX-bone resorption marker) and procollagen type I amino-terminal propeptide (PINP-bone formation marker). An interim analysis, stratified by baseline BMD z-score ≤−2 (low BMD) vs. >−2 (normal BMD), was performed using the intention-to-treat analysis.
Results: Between April 2015 and October 2016, 166 adolescents were enrolled. The median age and ART duration were 16.0 and 10.0 years, respectively. The median baseline BMD z-score was −1.5, and 67 adolescents (40%) had low BMD. Overall adherence to VitD/Ca supplementation was 80%. At week 48, there was a significant increase in BMD z-scores in participants with low baseline BMD, particularly among those receiving “high-dose” compared with “normal-dose” supplementation (+0.74 vs. +0.49) (Table 1). The increased 25OHD and the declined iPTH, ALP, CTX and PINP levels were also observed in both treatment groups (p < 0.001). No between-group differences in changes from baseline for BMD z-scores and all bone biomarkers (p > 0.05), except for iPTH (p = 0.007).
Conclusions: With the preliminary results, BMD was significantly ameliorated in adolescents with low baseline BMD who received VitD/Ca supplementation, regardless of dose, over 48-week follow-up. A prospective study with longer follow-up is warranted to confirm our findings.
