Vitamin D supplementation prior to or during COVID-19 associated with better 3-month survival in geriatric patients: Extension phase of the GERIA-COVID study.

BACKGROUND: The objective of this extension phase of the quasi-experimental GERIA-COVID study was to determine whether vitamin D3 supplementation taken prior to or during COVID-19 was associated with better 3-month survival in geriatric patients hospitalized for COVID-19. METHODS: Intervention group was defined as all participants supplemented with vitamin D3 prior to or during COVID-19 (n = 67). Supplements were either bolus vitamin D3 (ie, 50,000 IU per month, or 80,000 IU or 100,000 IU or 200,000 IU every 2-3 months), or daily supplementation with 800 IU. Comparator group involved those without vitamin D supplements (n = 28). Outcome was 3-month mortality. Covariables were age, sex, functional abilities, history of malignancies, cardiomyopathy, undernutrition, number of acute health issues, antibiotics use, systemic corticosteroids use, and 25(OH)D concentration. RESULTS: 76.1 % (n = 51) of participants survived at 3 months in Intervention group, compared to only 53.6 % (n = 15) in Comparator group (P = 0.03). The fully-adjusted hazard ratio for 3-month mortality was HR = 0.23 [95 %CI: 0.09;0.58](P = 0.002) in Intervention group compared to Comparator group. Intervention group had also longer survival time (log-rank P = 0.008). CONCLUSIONS: Vitamin D3 supplementation was associated with better 3-month survival in older COVID-19 patients.

Role of vitamin D in treating COVID-19-associated coagulopathy: problems and perspectives.

Aggressive inflammatory response leading to hypercoagulability has been found to be associated with disease severity in COVID-19 patients and portends bad treatment outcome. A state of acute disseminated intravascular coagulation (DIC), along with pulmonary embolism and/or deep vein thrombosis, has been observed in critically ill ICU patients. Autopsy reports of COVID-19 patients demonstrated microthrombi in lungs and in other organs, as well as marked inflammatory changes, characteristic clinicopathological features that exacerbate disease severity. Vitamin D supplementation was recommended by many clinicians across the globe to improve clinical symptoms of COVID-19 patients, mainly because of its immunomodulatory roles on immune cells. Furthermore, vitamin D and its associated molecules are also known to directly or indirectly regulate various thrombotic pathways. We propose that vitamin D supplementation not only attenuates the risk of Acute Respiratory Disease Syndrome (ARDS) but it also may have a role in reducing coagulation abnormalities in critically ill COVID-19 patients. The overarching goal of this review is to discuss the effects of vitamin D on coagulation pathways and other intertwined processes leading to thrombosis. Many clinical trials are currently investigating the efficacy of vitamin D supplementation in reducing the risk of COVID-19 infection. However, randomized placebo control clinical trials are also necessary to ascertain the effect of vitamin D supplementation on reducing the risk of coagulopathy in COVID-19 patients.

l-Cysteine Stimulates the Effect of Vitamin D on Inhibition of Oxidative Stress, IL-8, and MCP-1 Secretion in High Glucose Treated Monocytes.

Objective: Vitamin D deficiency is common in the general population and diabetic patients, and supplementation with vitamin D is widely used to help lower oxidative stress and inflammation. The cytokine storm in SARS-CoV2 infection has been linked with both diabetes and Vitamin D deficiency. This study examined the hypothesis that supplementation with vitamin D, in combination with l-cysteine (LC), is better at reducing oxidative stress and thereby, more effective, at inhibiting the secretion of the pro-inflammatory cytokines, Interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) in U937 monocytes exposed to high glucose concentrations. Methods: U937 monocytes were pretreated with 1,25 (OH)2 vitamin D (VD, 10 nM) or LC (250 µM) or VD + LC for 24 h and then exposed to control or high glucose (HG, 25 mM) for another 24 h. Results: There were significantly greater reactive oxygen species (ROS) levels in monocytes treated with HG than those in controls. Combined supplementation with VD and LC showed a more significant reduction in ROS (46%) in comparison with treatment with LC (19%) or VD (26%) alone in monocytes exposed to HG. Similarly, VD supplementation, together with LC, caused a more significant inhibition in the secretion of IL-8 (36% versus 16%) and MCP-1 (46% versus 26%) in comparison with that of VD (10 nM) alone in high-glucose treated monocytes. Conclusions: These results suggest that combined supplementation with vitamin D and LC has the potential to be more effective than either VD or LC alone in lowering the risk of oxidative stress and inflammation associated with type 2 diabetes or COVID-19 infection. Further, this combined vitamin D with LC/N-acetylcysteine may be a potent alternative therapy for SARS-CoV2 infected subjects. This approach can prevent cellular damage due to cytokine storm in comorbid systemic inflammatory conditions, such as diabetes, obesity, and hypertension.

The importance of vitamin d metabolism as a potential prophylactic, immunoregulatory and neuroprotective treatment for COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic has led to a declaration of a Public Health Emergency of International Concern by the World Health Organization. As of May 18, 2020, there have been more than 4.7 million cases and over 316,000 deaths worldwide. COVID-19 is caused by a highly infectious novel coronavirus known as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), leading to an acute infectious disease with mild-to-severe clinical symptoms such as flu-like symptoms, fever, headache, dry cough, muscle pain, loss of smell and taste, increased shortness of breath, bilateral viral pneumonia, conjunctivitis, acute respiratory distress syndromes, respiratory failure, cytokine release syndrome (CRS), sepsis, etc. While physicians and scientists have yet to discover a treatment, it is imperative that we urgently address 2 questions: how to prevent infection in immunologically naive individuals and how to treat severe symptoms such as CRS, acute respiratory failure, and the loss of somatosensation. Previous studies from the 1918 influenza pandemic have suggested vitamin D's non-classical role in reducing lethal pneumonia and case fatality rates. Recent clinical trials also reported that vitamin D supplementation can reduce incidence of acute respiratory infection and the severity of respiratory tract diseases in adults and children. According to our literature search, there are no similar findings of clinical trials that have been published as of July 1st, 2020, in relation to the supplementation of vitamin D in the potential prevention and treatment for COVID-19. In this review, we summarize the potential role of vitamin D extra-renal metabolism in the prevention and treatment of the SARS-CoV-2 infection, helping to bring us slightly closer to fulfilling that goal. We will focus on 3 major topics here: 1. Vitamin D might aid in preventing SARS-CoV-2 infection: Vitamin D: Overview of Renal and Extra-renal metabolism and regulation. Vitamin D: Overview of molecular mechanism and multifaceted functions beyond skeletal homeostasis. Vitamin D: Overview of local immunomodulation in human infectious diseases. Anti-viral infection. Anti-malaria and anti-systemic lupus erythematosus (SLE). 2. Vitamin D might act as a strong immunosuppressant inhibiting cytokine release syndrome in COVID-19: Vitamin D: Suppression of key pro-inflammatory pathways including nuclear factor kappa B (NF-kB), interleukin-6 (IL-6), and tumor necrosis factor (TNF). 3. Vitamin D might prevent loss of neural sensation in COVID-19 by stimulating expression of neurotrophins like Nerve Growth Factor (NGF): Vitamin D: Induction of key neurotrophic factors. .

Risk Factors of Hypovitaminosis D in HIV-Infected Patients on Suppressive Antiretroviral Therapy.

Low serum vitamin D levels are very common in human immunodeficiency virus (HIV)-infected patients. In our cross-sectional study, we investigated the association between 25-hydroxyvitamin D (25(OH)D) levels and serum inflammation markers [C-reactive protein (CRP), white blood cells (WBC), D-dimers, platelet count (PLT)] in 148 HIV-infected patients on combined antiretroviral therapy [28 on tenofovir alafenamide (TAF)] and 40 healthy controls. The controls were significantly older (56.6 ± 19.1 years for HIV(-) vs. 45.1 ± 11.8 years for HIV(+); p = .001) and more females were observed in this group (65% for HIV(-) vs. 16.7% for HIV(+); p = .001). The vitamin D serum level was comparable in the two studied groups (74.2 ± 35.9 nmol/L for HIV(+) vs. 78.0 ± 27.6 nnmol/L for HIV(-), p = .545). In HIV-infected group, a significant positive correlation between CD4+ cell percentage and vitamin D level was observed (r = 0.17; p = .036). Furthermore, the significant negative correlation between vitamin D level and CD8+ cell percentage, PLT, CRP, and D-dimers was seen. In univariate analysis, only TAF use and AIDS status was associated with vitamin D level deficiency. No other antiretroviral (ARV) drug nor gender or smoking had influence on vitamin D serum level. In multivariate analysis, only AIDS status and CRP level were correlated with vitamin D level (slope estimate = 11.6 and p = .032 and slope estimate = -0.83 and p = .002; respectively). In summary, we report that low vitamin D level may be associated with high CRP level in HIV-infected patients on suppressive antiretroviral therapy, especially in AIDS phase. More larger studies are required to assess our observation concerning TAF use and vitamin D level in HIV-positive patients.

Considerations for Obesity, Vitamin D, and Physical Activity Amid the COVID-19 Pandemic.

As the biomedical community races to disentangle the unknowns associated with severe acute respiratory syndrome coronavirus 2, the virus responsible for causing coronavirus disease, the link between diminished immune function and individuals with obesity raises important questions about the possibility for greater viral pathogenicity in this population. Increased adiposity may undermine the pulmonary microenvironment wherein viral pathogenesis and immune cell trafficking could contribute to a maladaptive cycle of local inflammation and secondary injury. A further challenge to those with obesity during the current pandemic may involve vitamin D deficiency or insufficiency. In the interest of personal and public health, we caution decision- and policy makers alike not to pin all hope on a proverbial "silver bullet." Until further breakthroughs emerge, we should remember that modifiable lifestyle factors such as diet and physical activity should not be marginalized. Decades of empirical evidence support both as key factors promoting health and wellness.

Hypovitaminosis Din Postherpetic Neuralgia-High Prevalence and Inverse Association with Pain: A Retrospective Study.

Hypovitaminosis D (25-hydroxyvitamin D (25(OH)D) <75 nmol/L) is associated with neuropathic pain and varicella-zoster virus (VZV) immunity. A two-part retrospective hospital-based study was conducted. Part I (a case-control study): To investigate the prevalence and risk of hypovitaminosis D in postherpetic neuralgia (PHN) patients compared to those in gender/index-month/age-auto matched controls who underwent health examinations. Patients aged ≥50 years were automatically selected by ICD-9 codes for shingle/PHN. Charts were reviewed. Part II (a cross-sectional study): To determine associations between 25(OH)D, VZV IgG/M, pain and items in the DN4 questionnaire at the first pain clinic visit of patients. Independent predictors of PHN were presented as adjusted odds ratios(AOR) and 95% confidence intervals (CI). Prevalence (73.9%) of hypovitaminosis D in 88 patients was high. In conditional logistic regressions, independent predictors for PHN were hypovitaminosis D (AOR3.12, 95% CI1.73-5.61), malignancy (AOR3.21, 95% CI 1.38-7.48) and Helicobacter pylori-related peptic ulcer disease (AOR3.47, 95% CI 1.71-7.03). 25(OH)D was inversely correlated to spontaneous/brush-evoked pain. Spontaneous pain was positively correlated to VZV IgM. Based on the receiver operator characteristic curve, cutoffs for 25(OH)D to predict spontaneous and brush-evoked pain were 67.0 and 169.0 nmol/L, respectively. A prospective, longitudinal study is needed to elucidate the findings.

Tenofovir disoproxil fumarate appears to disrupt the relationship of vitamin D and parathyroid hormone.

BACKGROUND: Tenofovir disoproxil fumarate (TDF) increases serum parathyroid hormone (PTH) and 1,25 dihydroxy vitamin D (1,25-(OH)2D), and decreases bone mineral density (BMD). Optimal treatment of TDF-associated BMD loss requires an understanding of the primary cause of these abnormalities. METHODS: Secondary review of data from two studies of TDF use in youth, comparing the relationship of PTH, 25-hydroxy vitamin D (25-OHD) and 1,25-(OH)2D in three groups with varying exposures to TDF: youth without HIV enrolled in a trial of TDF/emtricitabine (FTC) for HIV pre-exposure prophylaxis (PrEP) at baseline (no TDF exposure) and after 12 weeks of TDF (short-term TDF exposure); and youth with HIV treated with TDF-containing combination antiretroviral therapy (cART) for at least 6 months at study entry (long-term TDF exposure). Relationships were evaluated by correlation analyses. RESULTS: Participants ranged in age from 17 to 24 years and >50% were Black/African American. In persons not treated with TDF, PTH had the physiologically appropriate negative correlation with 25-OHD (r=-0.3504, P=0.004). Correlations between PTH and 25-OHD in groups treated with TDF were weaker or absent. With longer term TDF treatment in persons with HIV, 25-OHD and 1,25-(OH)2D had the positive correlation similar to that found in vitamin D deficiency. CONCLUSIONS: TDF changes the relationship of 25-OHD to PTH, suggesting that in persons using TDF for PrEP or cART, a higher than usual target for serum 25-OHD concentration might be needed to reduce PTH and optimize bone health. CLINICAL TRIALS REGISTRATION: NCT01751646 (ATN 109) and NCT01769469 (ATN 117).

Vitamin D status in perinatally HIV-infected Thai children receiving antiretroviral therapy.

BACKGROUND: Low vitamin D level is associated with adverse health outcomes and compromises HIV treatment response. We assess vitamin D status in HIV-infected Thai children receiving combination antiretroviral therapy (cART). METHODS: A cross-sectional study in perinatally HIV-infected children. Vitamin D deficiency and vitamin D insufficiency were defined as serum 25-hydroxyvitamin D (25-OHD) level <20, and 21-29 ng/mL, respectively. RESULTS: Eighty participants were enrolled. Their median age was 12.2 years. The median CD4 lymphocyte count was 784 cell/mm3; 95% had HIV RNA <50 copies/mL. The median (interquartile range, IQR) 25-OHD level was 33.5 (26.2-39.8) ng/mL. Thirty-four (43%) participants had low vitamin D level; 26 (33%) and 8 (10%) had vitamin D insufficiency and deficiency, respectively. In multivariate analysis, only geographic location was significantly associated with low vitamin D level. CONCLUSIONS: Most of perinatally HIV-infected children receiving cART had low vitamin D level. Calcium and vitamin D supplement might be beneficial.

Low vitamin D levels are associated with the presence of serum cryoglobulins in patients with chronic HCV infection.

BACKGROUND/AIM: Mixed Cryoglobulinemia (MC) represents the most frequent extrahepatic manifestation of chronic Hepatitis C Virus (HCV) infection. Its pathogenic mechanisms involve HCV-induced chronic stimulation of B-lymphocytes. We aimed to investigate the relationship between serum levels of vitamin D (a regulator of immune response) and the presence of serum cryoglobulins in the setting of HCV infection. PATIENTS AND METHODS: We evaluated the serum concentration of 25(OH)vitamin D and cryoglobulins in 106 patients with chronic HCV infection. RESULTS: Thirty patients (28.3%) showed the presence of serum cryoglobulins. For the cohort overall, the median serum 25(OH)vitamin D level was 10.95 ng/ml. Patients with serum cryoglobulins had significantly lower levels of 25(OH)vitamin D (5.61 ng/ml) than those without (13.65 ng/ml, p=0.029). At multivariate analysis, severe hypovitaminosis [i.e. 25(OH)vitamin D <13 ng/ml] was the only independent predictor of cryoglobulinemia (odds ratio=3.108). CONCLUSION: Severe deficiency of vitamin D was independently associated with mixed cryoglobulinemia in patients with HCV infection.

Risk factors associated with hypovitaminosis D in HIV/aids-infected adults / Fatores de risco associados à hipovitaminose D em indivíduos adultos infectados pelo HIV/aids

Objective To investigate risk factors associated with hypovitaminosis D in adult patients infected with HIV/aids, at a referral hospital in Maceió, Brazil. Subjects and methods This cross-sectional study involved 125 patients evaluated from April to September 2013 by means of interviews, review of medical records, physical examination, and laboratory tests. The data were analyzed using the SPSS® software, version 17.0; the prevalence of hypovitaminosis D and mean levels of vitamin D were determined. The association between hypovitaminosis D and the independent variables was assessed using the Chi-square or the Fisher’s exact tests; mean vitamin D concentrations were analyzed using Kolmogorov-Smirnov, Mann-Whitney, and Kruskal-Wallis tests. The level of significance was set at 5% across tests. Results The prevalence of hypovitaminosis D was 24%, with a significant association with higher household income (p < 0.05). Higher vitamin D levels were associated with female gender (p < 0.001), no use of sunscreen (p < 0.05), and previous opportunistic infections (p < 0.01). Lower values were associated with the use of antiretroviral medication (p < 0.05), overweight and obesity (p < 0.01). Conclusion Lower vitamin D concentrations were significantly associated with well-known risk factors for hypovitaminosis D: use of sunscreen, antiretroviral medication, overweight, and obesity. The prevalence of hypovitaminosis D in this study, considering values > 20 ng/mL or > 30 ng/mL as vitamin D sufficiency, was lower to that of previous studies with HIV-infected patients, a fact that might be related to the low latitude and high intensity of solar radiation of the location of the present study. .

Objetivo Investigar fatores de risco associados à hipovitaminose D em pacientes adultos infectados por HIV/aids, num centro de referência em Maceió-AL. Sujeitos e métodos Por meio de desenho transversal, 125 pacientes foram avaliados por entrevista, revisão de prontuário, exame físico e laboratorial, no período de abril a setembro de 2013. Os dados foram analisados por meio do software SPSS®, versão 17.0, sendo determinados a prevalência de hipovitaminose D e os níveis médios de vitamina D. Para avaliação da associação entre hipovitaminose D e as variáveis pesquisadas, foram utilizados o teste Qui-quadrado ou o teste exato de Fisher, enquanto para os níveis médios de vitamina D foram utilizados os testes Kolmogorov-Smirnov, Mann-Whitney e Kruskal-Wallis. O nível de significância foi de 5% para todos os testes. Resultados Foi observada prevalência de hipovitaminose D de 24% com associação significativa com maior renda familiar (p < 0,05); níveis de vitamina D mais altos nas mulheres (p < 0,001), em pacientes que não faziam uso de filtro solar (p < 0,05) e naqueles com infecções oportunistas pregressas (p < 0,01). Valores mais baixos foram associados ao uso de antirretrovirais (p < 0,05), sobrepeso e obesidade (p < 0,01). Conclusão Níveis mais baixos de vitamina D estiveram significativamente associados com tradicionais fatores de risco para hipovitaminose D como uso de filtro solar e antirretrovirais, sobrepeso e obesidade. A prevalência de hipovitaminose encontrada, considerando suficiência de vitamina D tanto para valores acima de 20 ng/mL quanto de 30 ng/mL, foi inferior a estudos anteriores em pacientes infectados pelo HIV, fato que pode estar relacionado às características da localidade do estudo, com baixa latitude e elevada incidência solar. .

Lack of association between serum 25-hydroxyvitamin D levels and cervical human papillomavirus infection in systemic lupus erythematosus.

Our objective was to evaluate whether vitamin D deficiency is associated with cervical human papilloma virus (HPV) infection in women with SLE. This is a cross-sectional study of 67 women with SLE. A structured questionnaire was administered to ascertain the possible risk factors associated with cervical HPV infection. A gynaecological evaluation and cervical cytology screening were made. HPV detection and genotyping was made by PCR and linear array assay. Serum 25 hydroxyvitamin D levels were quantified by chemiluminescence immunoassay. Mean age and disease duration were 44.8 ± 10.6 and 42.5 ± 11.8 years, respectively. Demographic characteristics were similar in patients with and without deficiency (<20 ng/ml and ≥20 ng/ml). There were 28.4% of women with cervical HPV infection and 68.4% had high-risk HPV infections. Patients with 25 hydroxyvitamin D levels <20 ng/ml had a higher prevalence of cervical HPV infection than those with levels ≥20 ng/ml (30.7% vs. 25.8%; p = 0.72). We found no significant difference when high-risk HPV infection was evaluated (36.8% vs. 31.5%; p = 0.73). In conclusion, women with SLE have a high prevalence of vitamin D deficiency and cervical HPV infection. However, we found no association between vitamin D deficiency and cervical HPV.

Relationship of vitamin D insufficiency to AIDS-associated Kaposi's sarcoma outcomes: retrospective analysis of a prospective clinical trial in Zimbabwe.

OBJECTIVES: The prevalence of vitamin D insufficiency in Africans with AIDS-associated Kaposi sarcoma (AIDS-KS) and the role of vitamin D in AIDS-KS progression are unknown. We hypothesized that a high prevalence of vitamin D deficiency would be found in Zimbabweans with AIDS-KS and that low baseline vitamin D would correlate with progression of AIDS-KS. METHODS: Ninety subjects were enrolled in a prospective pilot study investigation of the effect of antiretroviral therapy in the treatment of AIDS-KS in Harare, Zimbabwe. Co-formulated abacavir, lamivudine, and zidovudine was initiated; chemotherapy was provided at the discretion of the provider. Participants were followed for 96 weeks. 25-Hydroxyvitamin D was measured in stored specimens collected at study entry. The relationship between vitamin D and clinical response was described by odds ratio and 95% confidence interval. RESULTS: Samples were available for 85 participants; 45 (53%) subjects had inadequate (<75 nmol/l) 25-hydroxyvitamin D. HIV-1 RNA was significantly higher among those with insufficient vitamin D (4.7 vs. 4.5 log, p = 0.04). Tumor response, survival, and KS-IRIS were not associated with vitamin D (p ≥ 0.3). CONCLUSIONS: Vitamin D insufficiency was common among Zimbabweans with AIDS-KS but not associated with outcomes after initiation of antiretroviral therapy.

Vitamin D deficiency is associated with severity of liver disease in HIV/HCV coinfected patients.

OBJECTIVE: To study the association of plasma 25-hydroxy vitamin D (25(OH)D) levels in HIV/HCV coinfected patients with severity of liver disease and virological response to hepatitis C virus (HCV) therapy with pegylated-interferon-alpha plus ribavirin (pegIFNα/RBV). METHODS: A cross-sectional study in 174 HIV/HCV coinfected patients that underwent a liver biopsy previously to start HCV therapy and a retrospective study of 125 of them. Plasma 25(OH)D levels were quantified by enzyme immunoassay. Liver biopsies were evaluated by METAVIR score. A sustained virological response (SVR) was defined as an undetectable serum HCV viral load (<10 IU/mL) up through 24 weeks after the end of HCV treatment. RESULTS: The median of plasma 25(OH)D level was 48 nmol/L (p25th: 32.5; p75th: 56.1) and 27 (15.5%) had 25(OH)D deficiency (<25 nmol/L). The percentage of 25(OH)D deficiency was higher in patients with significant fibrosis (F ≥ 2) (92.6% vs. 57.1%; p = 0.010) and moderate necroinflammatory activity grade (A ≥ 2) (85.2% vs. 60%; p = 0.043). However, adjusted logistic regression analyses showed that 25(OH)D deficiency was only associated with severity of liver disease [F ≥ 2 (OR = 8.47 (95% of confidence interval (CI) = 1.88; 38.3); p = 0.005) and A ≥ 2 (OR = 3.25 (95%CI = 1.06; 10.1); p = 0.040)]. Moreover, any significant relationship was found between 25(OH)D deficiency and SVR after HCV therapy. CONCLUSION: Plasma 25(OH)D deficiency was associated with liver disease severity in HIV/HCV coinfected patients, but it was not associated with HCV treatment failure.

Association of higher plasma vitamin D binding protein and lower free calcitriol levels with tenofovir disoproxil fumarate use and plasma and intracellular tenofovir pharmacokinetics: cause of a functional vitamin D deficiency?

Tenofovir disoproxil fumarate (TDF) causes bone, endocrine, and renal changes by an unknown mechanism(s). Data are limited on tenofovir pharmacokinetics and these effects. Using baseline data from a multicenter study of HIV-infected youth on stable treatment with regimens containing TDF (n = 118) or lacking TDF (n = 85), we measured cross-sectional associations of TDF use with markers of renal function, vitamin D-calcium-parathyroid hormone balance, phosphate metabolism (tubular reabsorption of phosphate and fibroblast growth factor 23 [FGF23]), and bone turnover. Pharmacokinetic-pharmacodynamic associations with plasma tenofovir and intracellular tenofovir diphosphate concentrations were explored among those receiving TDF. The mean age was 20.9 (standard deviation [SD], 2.0) years; 63% were male; and 52% were African American. Compared to the no-TDF group, the TDF group showed lower mean estimated glomerular filtration rates and tubular reabsorption of phosphate, as well as higher parathyroid hormone and 1,25-dihydroxy vitamin D [1,25-OH(2)D] levels. The highest quintile of plasma tenofovir concentrations was associated with higher vitamin D binding protein, lower free 1,25-OH(2)D, higher 25-OH vitamin D, and higher serum calcium. The highest quintile of intracellular tenofovir diphosphate concentration was associated with lower FGF23. Higher plasma tenofovir concentrations were associated with higher vitamin D binding protein and lower free 1,25-OH(2)D, suggesting a functional vitamin D deficiency explaining TDF-associated increased parathyroid hormone. The finding of lower FGF23 accompanying higher intracellular tenofovir diphosphate suggests that different mechanisms mediate TDF-associated changes in phosphate handling. Separate pharmacokinetic properties may be associated with distinct TDF toxicities: tenofovir with parathyroid hormone and altered calcium balance and tenofovir diphosphate with hypophosphatemia and FGF23 regulation. (The clinical trial registration number for this study is NCT00490412 and is available online at http://clinicaltrials.gov/ct2/show/NCT00490412.).

Vitamin D in HIV-Infected Patients.

Observational studies have noted very high rates of low 25(OH)D (vitamin D) levels in both the general and HIV-infected populations. In HIV-infected patients, low 25(OH)D levels are likely a combination of both traditional risk factors and HIV-specific and antiretroviral therapy-specific contributors. Because of this unique risk profile, HIV-infected persons may be at greater risk for low 25(OH)D levels and frank deficiency and/or may respond to standard repletion regimens differently than HIV-uninfected patients. Currently, the optimal repletion and maintenance dosing regimens for HIV-infected patients remain unknown, as do potential benefits of supplementation that may be unique to the HIV-infected population. This paper reviews data published on HIV infection and vitamin D health in adults over the last year.

Osteoprotegerin and bone turnover markers in heavily pretreated HIV-infected patients.

OBJECTIVES: To characterize osteoprotegerin (OPG) levels, bone remodelling and bone mineral density (BMD) in heavily pretreated HIV-infected patients on antiretroviral therapy, and to evaluate the clinical factors associated with bone density decline. METHODS: Heavily pretreated (> 5 years) HIV-positive patients were enrolled in this cross-sectional, observational study, which was based on a total body bone densitometry examination and a comprehensive evaluation of bone and mineral parameters. RESULTS: Sixty-eight patients (55 male and 13 female) with a median age of 41 years (range 25-60 years) were included in the study. Their antiretroviral treatment lasted for 82 months. On the basis of the World Health Organization criteria, nine patients (13.2%) were osteoporotic [T-score < -2.5 standard deviation (SD)] and 19 patients (27.9%) were osteopenic (T-score between -1 and -2.5). The principal outcomes associated with the presence of a low BMD were high OPG and lysylpyridinoline/creatinine ratio (Dpd) values. Most of the patients (39 of 48; 81.25%) showed vitamin D insufficiency [Vitamin D (25(OH)D) < 18 ng/mL] with secondary hyperparathyroidism (13 of 50 patients: 26%), which proved to be correlated to osteocalcin (BGP) levels [parathyroid hormone (PTH) vs. BGP: r = 0.34; P < 0.01]. There was an inverse correlation between T-scores and serum osteocalcin and alkaline phosphatase (AP) levels, on one hand, and Dpd, on the other. High AP and Dpd values were associated with relative risks of 4.1 [95% confidence interval (CI) = 1.01-17.6] and 7.2 (95% CI = 1.67-31.03), respectively, of a pathological T-score. Multivariate analysis revealed that the factors associated with the presence of osteopenia or osteoporosis were older age and lower body mass index. CONCLUSIONS: About 40% of our heavily pretreated subjects with advanced HIV infection had a low BMD, and 56% (24 of 44 patients) showed a high bone turnover rate with marked osteoclast activation. High OPG levels may protect against bone resorption.