Effects of vitamin D and calcium supplementation on bone mineral density among Thai youth using daily HIV pre-exposure prophylaxis

Safety of oral tenofovir disoproxil - emtricitabine for HIV preexposure prophylaxis in adults

PURPOSE OF REVIEW

This review focuses on the safety of oral tenofovir disoproxil and emtricitabine (FTC) combination for HIV preexposure prophylaxis (PrEP) in adults.

RECENT FINDINGS

Gastrointestinal adverse events are common after treatment initiation but usually resolve within weeks. Although clinical trials did not report an increased risk of serious renal adverse events or tubulopathy, meta-analyses suggest that tenofovir disoproxil -FTC is associated with a slight but non-clinically relevant decline in estimated glomerular filtration rate (eGFR). A decline to less than 60 mL/min remains a rare event, which mainly occurs in users with an age >50 years or a baseline creatinine clearance < 90 mL/min. Similarly, a slight reduction in bone mineral density (BMD) was observed in clinical trials, but it did not result in an increased risk of bone fracture. BMD reduction and eGFR decline tend to resolve after treatment discontinuation. No drug interaction with contraception has been reported in women and no safety signal emerged in pregnant and breastfeeding women.

SUMMARY

Oral tenofovir disoproxil-FTC for HIV PrEP appears safe and well tolerated for most individuals. This supports demedicalization strategies aiming at increasing the number of PrEP users.

Vitamin D and Calcium Supplementation Reverses Tenofovir-Caused Bone Mineral Density Loss in People Taking ART or PrEP: A Systematic Review and Meta-Analysis

Background

The decrease of bone mineral density (BMD) after the intake of Tenofovir disoproxil fumarate (TDF)-based drugs in people living with HIV/AIDS (PLWHA) and HIV-negative key populations under pre-exposure prophylaxis (PrEP) regimen raised concerns. Previous findings on the effects of vitamin D (VD) and calcium supplements and the recovery of BMD loss were inconclusive. The optimal doses of VD and calcium and its supplementary duration remained unknown. Therefore, we conducted a systematic review and meta-analysis to synthesize current evidence on VD and calcium supplements to inform clinical practice.

Methods

We searched PubMed, Web of Science, Cochrane library, and EMBASE databases for all placebo-controlled trials and prospective cohort studies published before March 5, 2021 that investigated VD and calcium supplements in participants taking TDF-based drugs. The keywords calcium, vitamin D, Tenofovir, and BMD were used for the searches. The primary outcome was changes of spine and hip BMD. A subgroup analysis was performed to determine the factors that were related to the effects of VD supplements on BMD. Locally weighted regression (loess) was used to determine the relationships of VD supplements, supplementary duration, and changes of BMD. This study was registered at PROSPERO (No. 42021231000).

Findings

Seven eligible studies including 703 participants were included in the analyses. The meta-analysis found that VD and calcium supplementation was related to a significant increase of BMD in the spine and hip [standardized mean difference (SMD) 0.43; 95% CI, 0.25 to 0.61, p = 0.009]. Moreover, positive dose-response relationships were demonstrated between doses of VD and calcium supplements, supplementary duration, and BMD recovery. Patients who took VD with the dose level of 4,000 IU/D obtained the highest BMD improvement (SMD 0.59, 95% CI, 0.43 to 0.74). No side effects were reported on VD and calcium supplementation.

Interpretation

We found the VD and calcium supplementation was associated with increases of BMD in participants taking TDF-based drugs. An optimal supplementary dose of 4,000 IU/D for VD was suggested for clinicians. The findings could be used in clinical practice to improve the BMD outcomes in people who were taking TDF-based drugs.Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/.

Vitamin D, respiratory infections, and chronic disease: Review of meta-analyses and randomized clinical trials

BACKGROUND

Observational studies have suggested associations of vitamin D deficiency (VDD) with respiratory tract infections, impaired bone health, and myriad chronic diseases.

OBJECTIVE

To assess potential causal relationships between vitamin D supplementation and a reduced risk of these conditions, a review of the evidence across available meta-analyses of randomized control trials (RCTs) and RCTs was performed.

METHOD

PubMed, Embase, Cochrane Library, and Web of Science were searched from their inception to March 2021. We included only RCTs and meta-analyses of RCTs focusing on the association between vitamin D and respiratory disease, bone health, cardiovascular disease (CVD), diabetes mellitus, and cancer.

RESULTS

A total of 107 RCTs and 62 meta-analysis of RCTs were included. Although most RCTs did not support benefits of vitamin D supplementation, suggestive evidence for benefit was found in populations at greater risk of VDD and for acute respiratory infections, fractures in institutionalized older adults, type 2 diabetes among patients with prediabetes, and cancer mortality. In contrast, no compelling evidence for benefit was found for other respiratory conditions, fractures in community-dwelling adults, falls, cancer incidence, or CVD.

CONCLUSIONS

Current evidence from RCTs and meta-analyses of RCTs is inconsistent regarding the effects of vitamin D supplementation on respiratory infections and chronic diseases. Individuals most likely to benefit are those with baseline VDD or with selected high-risk conditions. Public health initiatives are needed to eliminate VDD globally, and future research will be enhanced by a 'precision prevention' approach to identify those most likely to benefit from vitamin D supplementation.

Efficacy of vitamin D supplementation among persons living with HIV/AIDS in São Paulo city, Brazil

Hypovitaminosis D is now considered a pandemic, especially among more vulnerable populations and in HIV-infected subjects, with 80% presenting levels below 30 ng/mL. As there is no consensus on the more adequate dosage needed to correct such deficiency, the objective of this study was to evaluate 25 (OH) vitamin D supplementation in HIV-1 patients deficient of vitamin D. A total of 73 HIV-1-infected patients were included, drawn from a cohort of 435 patients; 37 patients were randomized to the active group, supplemented once a week with 50,000 UI vitamin D by mouth (group 1) and 36 to the placebo group (group 2). The study period ranged from June 2016 to September 2017. Variables involved in vitamin D metabolism and risk factors associated with hypovitaminosis were evaluated. The mean age was 45 years and 31.5 % were women. Vitamin D supplementation was effective in normalizing serum levels after six months in group 1 (mean 35 ng/mL compared to 21 ng/mL for the placebo group; p = 0.04). No patient reached blood levels considered toxic (>100 UI). Efavirenz use can negatively influence vitamin D levels and supplementation is necessary as a likely adjunct to improving CD4+ T cells, resulting in greater effectiveness of the treatment. A weekly oral dose of 50,000 IU of vitamin D was sufficient to normalize the vitamin deficiency, safely and with good adherence among persons living with HIV/AIDS in Brazil.

Effects of vitamin D and calcium supplementation on bone mineral density among Thai youth using daily HIV pre-exposure prophylaxis

INTRODUCTION

Tenofovir disoproxil fumarate with emtricitabine (TDF/FTC) is used for HIV pre-exposure prophylaxis (PrEP). TDF may affect bone mineral density (BMD), particularly in youth who are at a stage of peak bone mass accrual. The objective of this study was to evaluate the effect of vitamin D and calcium supplementation on BMD among Thai youth receiving daily oral PrEP.

METHODS

This open-label randomized trial was conducted in male youth aged between 15 and 24 years. Participants were randomized to Arm A who received once-daily TDF/FTC plus vitamin D3 and calcium supplementation with meals twice daily (400 units of vitamin D3 and 1200 mg of elemental calcium/day) or Arm B who received once-daily TDF/FTC only. PrEP users were defined as taking at least two tablets/week (tenofovir-diphosphate level of >350 fmol/punch). Adherence to vitamin D/calcium supplementation was defined as self-reported adherence of >50%. Lumbar spine (L2-L4) BMD (LSBMD) was evaluated by dual-energy X-ray absorptiometry scan zero and six months after PrEP initiation.

RESULTS

From March 2019 to March 2020, 100 youth were enrolled. Baseline characteristics between the two arms were similar. Median (IQR) age was 18 (17 to 20) years. At entry, median (IQR) LSBMD z-score was -0.8 (-1.5 to -0.3), 17% had low LSBMD (Z-score < -2). The median amount of calcium intake from nutritional three-day recall was 167 (IQR 94 to 272) mg/day, 39% of participants had vitamin D deficiency, defined as 25(OH)D levels <20 IU/mL. At six months, 79 participants were evaluated. Of these, 42 (52%) were PrEP takers and 25 of 38 (66%) of arm A participants had good adherence to vitamin D/calcium supplementation. Significantly higher proportions of youth in arm A compared to arm B had >3% increase in LSBMD at month 6 compared to baseline (67.6% vs. 42.9% respectively; p = 0.03). There were significantly higher increases in LSBMD among youth with vitamin D deficiency who were supplemented; arm A + 0.05 (0 to 0.05) compared to arm B + 0.03 (-0.1 to 0.03), p = 0.04.

CONCLUSIONS

Increases in LSBMD over six months among youth using PrEP who received vitamin D/calcium supplementation was greater than those not supplemented. Long-term follow-up should be considered to explore long-term outcomes.