Metabolic activation of tachysterol3 to biologically active hydroxyderivatives that act on VDR, AhR, LXRs, and PPARγ receptors.

CYP11A1 and CYP27A1 hydroxylate tachysterol3 , a photoproduct of previtamin D3 , producing 20S-hydroxytachysterol3 [20S(OH)T3 ] and 25(OH)T3 , respectively. Both metabolites were detected in the human epidermis and serum. Tachysterol3 was also detected in human serum at a concentration of 7.3 ± 2.5 ng/ml. 20S(OH)T3 and 25(OH)T3 inhibited the proliferation of epidermal keratinocytes and dermal fibroblasts and stimulated the expression of differentiation and anti-oxidative genes in keratinocytes in a similar manner to 1,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ]. They acted on the vitamin D receptor (VDR) as demonstrated by image flow cytometry and the translocation of VDR coupled GFP from the cytoplasm to the nucleus of melanoma cells, as well as by the stimulation of CYP24A1 expression. Functional studies using a human aryl hydrocarbon receptor (AhR) reporter assay system revealed marked activation of AhR by 20S(OH)T3 , a smaller effect by 25(OH)T3 , and a minimal effect for their precursor, tachysterol3 . Tachysterol3 hydroxyderivatives showed high-affinity binding to the ligan-binding domain (LBD) of the liver X receptor (LXR) α and ß, and the peroxisome proliferator-activated receptor γ (PPARγ) in LanthaScreen TR-FRET coactivator assays. Molecular docking using crystal structures of the LBDs of VDR, AhR, LXRs, and PPARγ revealed high docking scores for 20S(OH)T3 and 25(OH)T3 , comparable to their natural ligands. The scores for the non-genomic-binding site of the VDR were very low indicating a lack of interaction with tachysterol3 ligands. Our identification of endogenous production of 20S(OH)T3 and 25(OH)T3 that are biologically active and interact with VDR, AhR, LXRs, and PPARγ, provides a new understanding of the biological function of tachysterol3 .

Calcifediol: a review of its pharmacological characteristics and clinical use in correcting vitamin D deficiency.

BACKGROUND: In addition to the role of vitamin D in bone mineralization, calcium and phosphate homeostasis, and skeletal health, evidence suggests an association between vitamin D deficiency and a wide range of chronic conditions. This is of clinical concern given the substantial global prevalence of vitamin D deficiency. Vitamin D deficiency has traditionally been treated with vitamin D3 (cholecalciferol) or vitamin D2 (ergocalciferol). Calcifediol (25-hydroxyvitamin D3) has recently become available more widely. METHODS: By means of targeted literature searches of PubMed, this narrative review overviews the physiological functions and metabolic pathways of vitamin D, examines the differences between calcifediol and vitamin D3, and highlights clinical trials conducted with calcifediol in patients with bone disease or other conditions. RESULTS: For supplemental use in the healthy population, calcifediol can be used at doses of up to 10 µg per day for children ≥ 11 years and adults and up to 5 µg/day in children 3-10 years. For therapeutic use of calcifediol under medical supervision, the dose, frequency and duration of treatment is determined according to serum 25(OH)D concentrations, condition, type of patient and comorbidities. Calcifediol differs pharmacokinetically from vitamin D3 in several ways. It is independent of hepatic 25-hydroxylation and thus is one step closer in the metabolic pathway to active vitamin D. At comparable doses to vitamin D3, calcifediol achieves target serum 25(OH)D concentrations more rapidly and in contrast to vitamin D3, it has a predictable and linear dose-response curve irrespective of baseline serum 25(OH)D concentrations. The intestinal absorption of calcifediol is relatively preserved in patients with fat malabsorption and it is more hydrophilic than vitamin D3 and thus is less prone to sequestration in adipose tissue. CONCLUSION: Calcifediol is suitable for use in all patients with vitamin D deficiency and may be preferable to vitamin D3 for patients with obesity, liver disease, malabsorption and those who require a rapid increase in 25(OH)D concentrations.

Bone Fragility in Hereditary Connective Tissue Disorders: A Systematic Review and Meta-Analysis.

OBJECTIVE: To investigate bone fragility in patients with hereditary connective tissue disorders (HCTD), including Ehlers-Danlos syndrome (EDS), Marfan's syndrome (MFS) and Loeys-Dietz syndrome (LDS). METHODS: From inception to June 2022, potentially eligible studies were identified in the Medline and EMBASE databases using search strategy that included terms for "HCTD", "Fracture" and "Osteoporosis". Eligible studies must consist of a group of patients with HCTD and report prevalence/incidence of fracture/osteoporosis in their participants, with or without comparison with healthy individuals. Point estimates with standard errors were obtained from each study and combined using the generic inverse variance method. RESULTS: Among the 4206 articles identified, 19 studies were included. The pooled prevalence of fracture in EDS, MFS, and LDS were 44% (95% confidence interval [CI], 25% to 65%, I2 88%), 17% (95% CI, 11% to 26%, I2 68%), 69% (95% CI, 47% to 85%, I2 83%), respectively. The pooled prevalence of osteoporosis in EDS was 17% (95% CI, 8% to 34%, I2 96%). EDS was associated with fracture [pooled odds ratio {OR} 4.90 (95% CI, 1.49 - 16.08, I2 86%)], but not osteoporosis [pooled OR 1.34 (95% CI, 0.28 - 6.36, I2 87%). One study reported a 5% (95% CI, 3% to 8%) prevalence of osteoporosis in MFS, which was associated with fracture [incidence rate ratio 1.35 (95% CI, 1.18 - 1.55)] and osteoporosis [subhazard ratio 3.97 (95% CI, 2.53 - 6.25)]. CONCLUSION: EDS was associated with fracture, which could be independent of osteoporosis status. MFS had a milder degree of increased risk of fracture and osteoporosis. Despite no data from cohort studies, there was a significantly higher rate of fracture in LDS.

Association of vitamin D status with COVID-19 and its severity : Vitamin D and COVID-19: a narrative review.

Vitamin D is associated with biological activities of the innate and adaptive immune systems, as well as inflammation. In observational studies, an inverse relationship has been found between serum 25-hydroxyvitamin D (25(OH)D) concentrations and the risk or severity of coronavirus disease 2019 (COVID-19). Several mechanisms have been proposed for the role of vitamin D in COVID-19, including modulation of immune and inflammatory responses, regulation of the renin-angiotensin-aldosterone system, and involvement in glucose metabolism and cardiovascular system. Low 25(OH)D concentrations might predispose patients with COVID-19 to severe outcomes not only via the associated hyperinflammatory syndrome but also by worsening preexisting impaired glucose metabolism and cardiovascular diseases. Some randomized controlled trials have shown that vitamin D supplementation is beneficial for reducing severe acute respiratory syndrome coronavirus 2 RNA positivity but not for reducing intensive care unit admission or all-cause mortality in patients with moderate-to-severe COVID-19. Current evidence suggests that taking a vitamin D supplement to maintain a serum concentration of 25(OH)D of at least 30 ng/mL (preferred range 40-60 ng/mL), can help reduce the risk of COVID-19 and its severe outcomes, including mortality. Although further well designed studies are warranted, it is prudent to recommend vitamin D supplements to people with vitamin D deficiency/insufficiency during the COVID-19 pandemic according to international guidelines.

The lower basal metabolic rate is associated with increased risk of osteosarcopenia in postmenopausal women.

BACKGROUND: The goal of this study is to clarify clinical, functional, and biochemical features of postmenopausal women who are at risk of developing osteosarcopenia. METHODS: This is a cross-sectional study undertaken to investigate the co-accordance of osteoporosis and sarcopenia and common risk factors on 305 postmenopausal Iranian women. Sarcopenia and osteoporosis were defined based on the European Working Group on sarcopenia in Older People guidelines and WHO criteria, respectively. Confounding factors including age, menopausal age, obesity, sun exposure, physical activity, macronutrient composition, and calcium and vitamin D supplementations were considered for all participants. A multivariate model was used to consider the common risk factors of both disorders; osteoporosis and sarcopenia. RESULTS: The mean age was 57.9 years ± 6.0 SD (range: 48-78 years) and 37.4% of patients were 60 years or older. Among all participants, 35.7% were obese (BMI ≥ 30 kg/m2). Approximately 45% of all the study population had insufficient physical activity and at least half of participants had insufficient intake of protein. There was a significant correlation between bone density and muscle mass and basal metabolic rate (BMR) (p < 0.01). In multivariate-multivariable regression model, after Bonferroni correction for obesity, lower BMR was the only one associated with both lower muscle mass and bone density in lumbar and hip sites (p < 0.007). CONCLUSIONS: Our data suggest that low BMR might be an early predictor for concordance of osteoporosis and sarcopenia in postmenopausal women.

The coronavirus disease (COVID-19) - A supportive approach with selected micronutrients.

Worldwide the pandemic of COVID-19 spreads rapidly and has had an enormous public health impact with substantial morbidity and mortality especially in high-risk groups, such as older people and patients with comorbidities like diabetes, dementia or cancer. In the absence of a vaccine against COVID-19 there is an urgent need to find supportive therapies that can stabilize the immune system and can help to deal with the infection, especially for vulnerable groups such as the elderly. This is especially relevant for our geriatric institutions and nursing homes. A major potential contributing factor for elderly is due to their high incidence of malnutrition: up to 80% among the hospitalized elderly. Malnutrition results when adequate macronutrients and micronutrients are lacking in the diet. Often missing in public health discussions around preventing and treating COVID-19 patients are nutritional strategies to support optimal function of their immune system. This is surprising, given the importance that nutrients play a significant role for immune function. Several micronutrients, such as vitamin D, retinol, vitamin C, selenium and zinc are of special importance supporting both the adaptive and innate immune systems. As suboptimal status or deficiencies in these immune-relevant micronutrients impair immune function and reduces the resistance to infections, micronutrient deficiencies should therefore be corrected as soon as possible, especially in the elderly and other vulnerable groups. According to epidemiological, experimental and observational studies, some case reports and a few intervention studies the supplementation of vitamin D and/or zinc are promising. The multiple anti-inflammatory and immunomodulatory effects of Vitamin D could explain its protective role against immune hyper reaction and cytokine storm in patients with severe COVID-19. A randomized, placebo-controlled intervention study even shows that high dose vitamin D supplementation promotes viral clearance in asymptomatic and mildly symptomatic SARS-CoV-2 positive individuals. Besides, the data of a recent prospective study with COVID-19 patients reveal that a significant number of them were zinc deficient. The zinc deficient patients had more complications and the deficiency was associated with a prolonged hospital stay and increased mortality. Thus, immune-relevant micronutrients may help to increase the physiological resilience against COVID-19.

Self-identified Race and COVID-19-Associated Acute Kidney Injury and Inflammation: a Retrospective Cohort Study of Hospitalized Inner-City COVID-19 Patients.

BACKGROUND: Black individuals have been disproportionately affected by the coronavirus disease 2019 (COVID-19). However, it remains unclear whether there are any biological factors that predispose Black patients to COVID-19-related morbidity and mortality. OBJECTIVE: To compare in-hospital morbidity, mortality, and inflammatory marker levels between Black and White hospitalized COVID-19 patients. DESIGN AND PARTICIPANTS: This single-center retrospective cohort study analyzed data for Black and White patients aged ≥18 years hospitalized with a positive SARS-CoV-2 PCR test between March 1, 2020, and August 4, 2020. MAIN MEASURES: The exposure was self-identified race documented in the medical record. The primary outcome of was in-hospital death. Secondary outcomes included intensive care unit admission, hospital morbidities, and inflammatory marker levels. KEY RESULTS: A total of 1,424 Black and White patients were identified. The mean ± SD age was 56.1 ± 17.4 years, and 663 (44.5%) were female. There were 683 (48.0%) Black and 741 (52.0%) White patients. In the univariate analysis, Black patients had longer hospital stays (8.1 ± 10.2 vs. 6.7 ± 8.3 days, p = 0.011) and tended to have higher rates of in-hospital death (11.0% vs. 7.3%), myocardial infarction (6.9% vs. 4.5%), pulmonary embolism (PE; 5.0% vs. 2.3%), and acute kidney injury (AKI; 39.4% vs. 23.1%) than White patients (p <0.05). However, after adjusting for potential confounders, only PE (adjusted odds ratio [aOR] 2.07, 95% CI, 1.13-3.79) and AKI (aOR 2.16, 95% CI, 1.57-2.97) were statistically significantly associated with Black race. In comparison with White patients, Black patients had statistically significantly higher peak plasma D-dimer (standardized ß = 0.10), erythrocyte sedimentation rate (standardized ß = 0.13), ferritin (standardized ß = 0.09), and lactate dehydrogenase (standardized ß = 0.11), after adjusting for potential confounders (p<0.05). CONCLUSIONS: Black hospitalized COVID-19 patients had increased risks of developing PE and AKI and higher inflammatory marker levels compared with White patients. This observation may be explained by differences in the prevalence and severity of underlying comorbidities and other unmeasured biologic risk factors between Black and White patients. Future research is needed to investigate the mechanism of these observed differences in outcomes of severe COVID-19 infection in Black versus White patients.

Sun-induced production of vitamin D3 throughout 1 year in tropical and subtropical regions: relationship with latitude, cloudiness, UV-B exposure and solar zenith angle.

This study evaluated the differences in vitamin D3 synthesis in two different latitudes throughout 1 year using an in vitro model, which simulates cutaneous vitamin D photoproduction. Borosilicate ampoules containing 7-dehydrocholesterol (7-DHC) were exposed to sunlight hourly throughout the daylight hours, 1 day per month for a year, in Fortaleza (latitude 03° 43' 01" S-LAT3° S) and Sao Paulo (latitude 23° 32' 53" S-LAT23° S). Later, vitamin D3 and photoisomers of 7-DHC (tachysterol and lumisterol) were measured by a high-performance liquid chromatography system (HPLC). Vitamin D synthesis weighted UV radiation (UVBVitD) and solar zenith angle (SZA) were calculated during the same periods for both latitudes. Vitamin D3 synthesis occurred throughout the year in both locations, as expected in latitudes lower than 35°. Median of photoconversion to vitamin D3 through the year was higher in LAT3°S [median (IQR): LAT 3°S 4.1% (6.0); LAT 23°S 2.9% (4.5); p value = 0.020]. Vitamin D3 production strongly correlated with UV-B (LAT3° S, r = 0.917; p < 0.0001 and at LAT23° S, r = 0.879; p < 0.0001) and SZA (LAT3° S, r = - 0.924; p < 0.0001 and in LAT23°S, r = - 0.808; p < 0.0001). Vitamin D3 production starts later in LAT23° S, especially in winter. Lowest percentages were observed in June in both cities, although, compared to LAT3° S, in LAT 23° S the conversion was over 50% lower in the winter period. Cloudiness impaired photoproduction of Vitamin D3 even in summer months in both latitudes. Our results provide data to help guide medical recommendations for sensible sun exposure to promote the cutaneous production of vitamin D3 at different latitudes, seasonality, time of day and cloudiness status in Brazil.

Vitamin D and Its Potential Benefit for the COVID-19 Pandemic.

Vitamin D is known not only for its importance for bone health but also for its biologic activities on many other organ systems. This is due to the presence of the vitamin D receptor in various types of cells and tissues, including the skin, skeletal muscle, adipose tissue, endocrine pancreas, immune cells, and blood vessels. Experimental studies have shown that vitamin D exerts several actions that are thought to be protective against coronavirus disease (COVID-19) infectivity and severity. These include the immunomodulatory effects on the innate and adaptive immune systems, the regulatory effects on the renin-angiotensin-aldosterone-system in the kidneys and the lungs, and the protective effects against endothelial dysfunction and thrombosis. Prior to the COVID-19 pandemic, studies have shown that vitamin D supplementation is beneficial in protecting against risk of acquiring acute respiratory viral infection and may improve outcomes in sepsis and critically ill patients. There are a growing number of data connecting COVID-19 infectivity and severity with vitamin D status, suggesting a potential benefit of vitamin D supplementation for primary prevention or as an adjunctive treatment of COVID-19. Although the results from most ongoing randomized clinical trials aiming to prove the benefit of vitamin D supplementation for these purposes are still pending, there is no downside to increasing vitamin D intake and having sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at a level of least 30 ng/mL (75 nmol/L) and preferably 40 to 60 ng/mL (100-150 nmol/L) to minimize the risk of COVID-19 infection and its severity.

Association of Vitamin D Status With Hospital Morbidity and Mortality in Adult Hospitalized Patients With COVID-19.

OBJECTIVE: To determine the association between vitamin D status and morbidity and mortality in adult hospitalized coronavirus disease 2019 (COVID-19) patients METHODS: We performed a retrospective chart review study in COVID-19 patients aged ≥18 year hospitalized at Boston University Medical Center between March 1 and August 4, 2020. All studied patients tested positive for COVID-19 and had serum levels of 25-hydroxyvitamin D (25[OH]D) results measured within 1 year prior to the date of positive tests. Medical information was retrieved from the electronic medical record and was analyzed to determine the association between vitamin D status and hospital morbidity and mortality. RESULTS: Among the 287 patients, 100 (36%) were vitamin D sufficient (25[OH]D >30 ng/mL) and 41 (14%) died during hospitalization. Multivariate analysis in patients aged ≥65 years revealed that vitamin D sufficiency (25[OH]D ≥30 ng/mL) was statistically significantly associated with decreased odds of death (adjusted OR 0.33, 95% CI, 0.12-0.94), acute respiratory distress syndrome (adjusted OR 0.22, 95% CI, 0.05-0.96), and severe sepsis/septic shock (adjusted OR 0.26, 95% CI, 0.08-0.88), after adjustment for potential confounders. Among patients with body mass index <30 kg/m2, vitamin D sufficiency was statistically significantly associated with a decreased odds of death (adjusted OR 0.18, 95% CI, 0.04-0.84). No significant association was found in the subgroups of patients aged <65 years or with body mass index ≥30 kg/m2. CONCLUSION: We revealed an independent association between vitamin D sufficiency defined by serum 25(OH)D ≥30 ng/mL and decreased risk of mortality from COVID-19 in elderly patients and patients without obesity.

Treatment With 25-Hydroxyvitamin D3 (Calcifediol) Is Associated With a Reduction in the Blood Neutrophil-to-Lymphocyte Ratio Marker of Disease Severity in Hospitalized Patients With COVID-19: A Pilot Multicenter, Randomized, Placebo-Controlled, Double-Blinded Clinical Trial.

OBJECTIVE: The goal of this randomized, double-blinded, placebo-controlled clinical trial was to investigate the therapeutic efficacy of oral 25-hydroxyvitamin D3 (25(OH)D3) in improving vitamin D status in vitamin D-deficient/vitamin D-insufficient patients infected with the SARS-CoV-2 (COVID-19) virus. METHODS: This is a multicenter, randomized, double-blinded, placebo-controlled clinical trial. Participants were recruited from 3 hospitals that are affiliated to [Institution Blinded for Review] and [Institution Blinded for Review]. RESULTS: A total 106 hospitalized patients who had a circulating 25(OH)D3 concentration of <30 ng/mL were enrolled in this study. Within 30 and 60 days, 76.4% (26 of 34) and 100% (24 of 24) of the patients who received 25(OH)D3 had a sufficient circulating 25(OH)D3 concentration, whereas ≤12.5% of the patients in the placebo group had a sufficient circulating 25(OH)D3 concentration during the 2-month follow-up. We observed an overall lower trend for hospitalization, intensive care unit duration, need for ventilator assistance, and mortality in the 25(OH)D3 group compared with that in the placebo group, but differences were not statistically significant. Treatment with oral 25(OH)D3 was associated with a significant increase in the lymphocyte percentage and decrease in the neutrophil-to-lymphocyte ratio in the patients. The lower neutrophil-to-lymphocyte ratio was significantly associated with reduced intensive care unit admission days and mortality. CONCLUSION: Our analysis indicated that oral 25(OH)D3 was able to correct vitamin D deficiency/insufficiency in patients with COVID-19 that resulted in improved immune function by increasing blood lymphocyte percentage. Randomized controlled trials with a larger sample size and higher dose of 25(OH)D3 may be needed to confirm the potential effect of 25(OH)D3 on reducing clinical outcomes in patients with COVID-19.

Is the natural UV zone important for successful captive propagation of the Panther Chameleon (Furcifer pardalis); are different UVB irradiance exposures that generate a similar dose equally successful?

While we generally understand the optimal ultraviolet B (UVB) environment for the growth and reproduction of female Panther Chameleons Furcifer pardalis, we do not know the relative importance of UVB irradiance and dose for optimal husbandry outcomes. Accordingly, we experimented with Panther Chameleon females to test the hypothesis that UVB dose (irradiance × exposure duration) determines the outcome, regardless of the combination of UVB irradiance and exposure duration generating the dose. We varied UVB irradiance and exposure duration across treatment groups while keeping dose similar and within a range previously documented to result in reproductive success. The growth rate, age of maturity, and measurable vitamin D status were not significantly different among the treatment groups. Individuals in all groups produced viable eggs that successfully hatched. Thus, we found some support for the hypothesis that the UVB dose determines the outcome regardless of UVB irradiance. However, mean egg vitamin D3 concentration and percent hatching were higher in the highest UVB irradiance group, despite similar doses among the three groups. Preliminary field data reveal that this species occupies UV irradiance Zone 4 in Madagascar, the highest zone for reptiles recorded. Only the irradiance of the high UVB irradiance group in our experiment approached this zone and resulted in the best reproductive success. Biosynthesis of vitamin D3 and provisioning to eggs is more efficient when exposure to UVB irradiance is similar to that in their natural environment. Establishing an optimal UVB environment, based on knowledge of the natural UVB environment, is important for the propagation of Panther Chameleons in captivity.

COVID-19 and Vitamin D: A lesson from the skin.

The negative outcomes of COVID-19 diseases respiratory distress (ARDS) and the damage to other organs are secondary to a "cytokine storm" and to the attendant oxidative stress. Active hydroxyl forms of vitamin D are anti-inflammatory, induce antioxidative responses, and stimulate innate immunity against infectious agents. These properties are shared by calcitriol and the CYP11A1-generated non-calcemic hydroxyderivatives. They inhibit the production of pro-inflammatory cytokines, downregulate NF-κΒ, show inverse agonism on RORγ and counteract oxidative stress through the activation of NRF-2. Therefore, a direct delivery of hydroxyderivatives of vitamin D deserves consideration in the treatment of COVID-19 or ARDS of different aetiology. We also recommend treatment of COVID-19 patients with high-dose vitamin D since populations most vulnerable to this disease are likely vitamin D deficient and patients are already under supervision in the clinics. We hypothesize that different routes of delivery (oral and parenteral) will have different impact on the final outcome.

Alcohol and Bone Turnover Markers among People Living with HIV and Substance Use Disorder.

BACKGROUND: Although unhealthy alcohol use and low bone density are prevalent among people living with HIV (PLWH), it is not clear whether alcohol use is associated with bone turnover markers (BTMs), and if so, at what quantity and frequency. The study objective was to examine the association between alcohol and BTMs in PLWH with substance use disorder. METHODS: We studied a prospective cohort recruited from 2 HIV clinics who met criteria for DSM-IV substance dependence or reported ever injection drug use. Outcomes were BTM of (i) bone formation (serum procollagen type 1 N-terminal propeptide [P1NP]) and (ii) bone resorption (serum C-telopeptide type 1 collagen [CTx]). Alcohol consumption measures included (i) mean number of drinks/d (Timeline Follow-Back [TLFB]) (primary predictor), (ii) any alcohol use on ≥20 of the past 30 days, and phosphatidylethanol (PEth), a biomarker of recent alcohol consumption. Linear regression analysis examined associations between (i) each alcohol measure and each BTM and (ii) change in alcohol and change in BTM over 12 months. RESULTS: Among 198 participants, baseline characteristics were as follows: The median age was 50 years; 38% were female; 93% were prescribed antiretroviral medications; 13% had ≥20 drinking days/month; mean drinks/day was 1.93 (SD 3.89); change in mean drinks/day was -0.42 (SD 4.18); mean P1NP was 73.1 ng/ml (SD 34.5); and mean CTx was 0.36 ng/ml (SD 0.34). Higher drinks/day was significantly associated with lower P1NP (slope -1.09 ng/ml; 95% confidence interval [CI] -1.94, -0.23, per each additional drink). On average, those who drank on ≥ 20 days/month had lower P1NP (-15.45 ng/ml; 95% CI: -26.23, -4.67) than those who did not. Similarly, PEth level ≥ 8ng/ml was associated with lower P1NP. An increase in drinks/d was associated with a decrease in P1NP nonsignificantly (-1.14; 95% CI: -2.40, +0.12; p = 0.08, per each additional drink). No significant associations were detected between either alcohol measure and CTx. CONCLUSIONS: In this sample of PLWH with substance use disorder, greater alcohol consumption was associated with lower serum levels of bone formation markers.

Diagnosis and management of pediatric metabolic bone diseases associated with skeletal fragility.

PURPOSE OF REVIEW: The goal of this review is to give an overview of diagnosis and up-to-date management of major pediatric metabolic bone diseases that are associated with bone fragility, including nutritional rickets, hypophosphatemic rickets, osteogenesis imperfecta, Ehlers--Danlos syndrome, Marfan's syndrome, hypophosphatasia, osteopetrosis and skeletal fluorosis. RECENT FINDINGS: During the past decade, a number of advanced treatment options have been introduced and shown to be an effective treatment in many metabolic bone disorders, such as burosumab for hypophosphatemic rickets and asfotase alfa for hypophosphatasia. On the other hand, other disorders, such as nutritional rickets and skeletal fluorosis continue to be underrecognized in many regions of the world. Genetic disorders of collagen-elastin, such as osteogenesis imperfecta, Ehlers--Danlos syndrome and Marfan's syndrome are also associated with skeletal fragility, which can be misdiagnosed as caused by non-accidental trauma/child abuse. SUMMARY: It is essential to provide early and accurate diagnosis and treatment for pediatric patients with metabolic bone disorders in order to maintain growth and development as well as prevent fractures and metabolic complications.

Sunlight, UV Radiation, Vitamin D, and Skin Cancer: How Much Sunlight Do We Need?

Vitamin D is the sunshine vitamin for good reason. During exposure to sunlight, the ultraviolet B photons enter the skin and photolyze 7-dehydrocholesterol to previtamin D3 which in turn is isomerized by the body's temperature to vitamin D3. Most humans have depended on sun for their vitamin D requirement. Skin pigment, sunscreen use, aging, time of day, season, and latitude dramatically affect previtamin D3 synthesis. Vitamin D deficiency was thought to have been conquered, but it is now recognized that more than 50% of the world's population is at risk for vitamin D deficiency. This deficiency is in part due to the inadequate fortification of foods with vitamin D and the misconception that a healthy diet contains an adequate amount of vitamin D. Vitamin D deficiency causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis and increase risk of fracture in adults. The vitamin D deficiency pandemic has other serious consequences including increased risk of common cancers, autoimmune diseases, infectious diseases, and cardiovascular disease. There needs to be a renewed appreciation of the beneficial effect of moderate sensible sunlight for providing all humans with their vitamin D requirement for health.

Longitudinal association of 25-hydroxyvitamin D with adipokines and markers of glucose metabolism among Brazilian pregnant women.

This study aimed to evaluate the longitudinal association of vitamin D status with glycaemia, insulin, homoeostatic model assessment of insulin resistance, adiponectin and leptin. A prospective cohort with 181 healthy, pregnant Brazilian women was followed at the 5th-13th, 20th-26th and 30th-36th gestational weeks. In this cohort, 25-hydroxyvitamin D (25(OH)D) plasma concentrations were analysed using liquid chromatography-tandem MS. Vitamin D status was categorised as sufficient or insufficient using the Endocrine Society Practice Guidelines (≥75/<75 nmol/l) and the Institute of Medicine (≥50/<50 nmol/l) thresholds. Linear mixed-effect regression models were employed to evaluate the association between vitamin D status and each outcome, considering interaction terms between vitamin D status and gestational age (P<0·1). At baseline, 70·7 % of pregnant women had 25(OH)D levels <75 nmol/l and 16 % had levels <50 nmol/l. Women with sufficient vitamin D status at baseline, using both thresholds, presented lower glycaemia than those with insufficient 25(OH)D. Pregnant women with 25(OH)D concentrations <75 nmol/l showed lower insulin (ß=-0·12; 95 % CI -0·251, 0·009; P=0·069) and adiponectin (ß=-0·070; 95 % CI -0·150, 0·010; P=0·085) concentrations throughout pregnancy than those with 25(OH)D levels ≥75 nmol/l. Pregnant women with 25(OH)D <50 nmol/l at baseline presented significantly higher leptin concentrations than those with 25(OH)D levels ≥50 nmol/l (ß=-0·253; 95 % CI -0·044, 0·550; P=0·095). The baseline status of vitamin D influences the biomarkers involved in glucose metabolism. Vitamin D-sufficient women at baseline had higher increases in insulin and adiponectin changes throughout gestation than those who were insufficient.

Vitamin D deficiency and its relationship to cancer stage in patients who underwent thyroidectomy for papillary thyroid carcinoma.

PURPOSE: As imaging technology improves and more thyroid nodules and malignancies are identified, it is important to recognize factors associated with malignancy and poor prognosis. Vitamin D has proven useful as a prognostic tool for other cancers and may be similarly useful in thyroid cancer. This study explores the relationship of Vitamin D to papillary thyroid carcinoma stage while accounting for socioeconomic covariates. MATERIALS AND METHODS: The medical records of all patients who underwent thyroidectomy at one institution between 2000 and 2015 were reviewed. Subjects with non-papillary thyroid cancer pathology, prior malignancy, and without Vitamin D levels were excluded. The remaining 334 patient records were examined for cancer stage, Vitamin D levels, Vitamin D deficiency listed in history, and demographic and comorbid factors. RESULTS: Vitamin D laboratory values showed no significant relationship to cancer stage (p = 0.871), but patients with Vitamin D deficiency documented in the medical record were more likely to have advanced disease (28.6% versus 14.7%; p = 0.028). The patients with documented Vitamin D deficiency also had lower 25-hydroxyvitamin D nadirs (21.5 ng/mL versus 26.5 ng/mL, p = 0.008) and were more likely to be on Vitamin D supplementation (92.6% versus 41.8%, p < 0.001). CONCLUSIONS: The results suggest that Vitamin D deficiency may have value as a negative prognostic indicator in papillary thyroid cancer and that pre-operative laboratory evaluation may be less useful. This is important because Vitamin D deficiency is modifiable. While different racial subgroups had different rates of Vitamin D deficiency, neither race nor socioeconomic status showed correlation with cancer stage.

Dietary Protein and Preservation of Physical Functioning Among Middle-Aged and Older Adults in the Framingham Offspring Study.

Dietary protein may help prevent age-related declines in strength and functional capacity. This study examines the independent relationship between dietary protein and longitudinal changes in physical functioning among adults participating in the Framingham Offspring Study from examination 5 (1991-1995) to examination 8 (2005-2008). Protein intakes were derived from 3-day diet records during examinations 3 and 5; functional status was determined over 12 years using 7 items selected from standardized questionnaires. Multivariable models adjusted for age, sex, education, physical activity, smoking, height, and energy intake. Functional tasks that benefitted most from a higher-protein diet (≥1.2 g/kg/day vs. <0.8 g/kg/day) were doing heavy work at home, walking 1/2 mile (0.8 km), going up and down stairs, stooping/kneeling/crouching, and lifting heavy items. Those with higher protein intakes were 41% less likely (95% CI: 0.43, 0.82) to become dependent in 1 or more of the functional tasks over follow-up. Higher physical activity and lower body mass index were both independently associated with less functional decline. The greatest risk reductions were found among those with higher protein intakes combined with either higher physical activity, more skeletal muscle mass, or lower body mass index. This study demonstrates that dietary protein intakes above the current US Recommended Daily Allowance may slow functional decline in older adults.

Alcohol Consumption and Bone Mineral Density in People with HIV and Substance Use Disorder: A Prospective Cohort Study.

BACKGROUND: People living with HIV (PLWH) commonly have low bone mineral density (BMD) (low bone mass and osteoporosis) and are at high risk for fractures. Fractures and low BMD are significant causes of morbidity and mortality, increasingly relevant as PLWH age. Alcohol use is common among PLWH and known to affect bone health. The association between alcohol use and changes in BMD among PLWH is not well understood. METHODS: We conducted a 3.5-year prospective cohort study of 250 PLWH with substance use disorder or ever injection drug use. Annual alcohol consumption was measured as a mean of grams per day of alcohol, mean number of heavy drinking days per month, mean number of days abstinent per month, and any heavy drinking, using the 30-day Timeline Followback method twice each year. The primary outcome was annual change in BMD measured each year by dual energy X-ray absorptiometry in grams per square centimeter (g/cm2 ) at the femoral neck. Additional dependent variables included annual change in total hip and lumbar spine BMD, >6% annual decrease in BMD at any site, and incident fractures in the past year. Regression models adjusted for relevant covariates. RESULTS: The median age of participants was 50 years. The median duration of HIV infection was 16.5 years and the mean time since antiretroviral therapy initiation was 12.3 years. At study entry, 67% of participants met criteria for low BMD (46% low bone mass, 21% osteoporosis). Median follow-up was 24 months. We found no significant associations between any measure of alcohol consumption and changes in BMD (g/cm2 ) at the femoral neck (adjusted ß for g/d of alcohol = -0.0032, p = 0.7487), total hip, or lumbar spine. There was no significant association between any measure of alcohol consumption and >6% annual decrease in BMD at any site, or incident fractures. CONCLUSIONS: In this sample of PLWH and substance use disorders or ever injection drug use, we detected no association between any of the alcohol measures used in the study and changes in BMD or incident fractures.