Characterization of vitamin D deficiency and use of a standardized supplementation protocol in orthopaedic trauma patients.

PURPOSE: The objectives of this study were to assess the incidence of vitamin D deficiency in orthopaedic trauma patients, evaluate the safety and efficacy of a vitamin D supplementation protocol, and investigate the utility of vitamin D supplementation in reducing nonunions. METHODS: Three hundred seventy patients with operative tibia and/or fibula fractures were retrospectively reviewed. Both overall and matched cohorts were analysed. RESULTS: Ninety-eight per cent (n = 210) were found to have vitamin D insufficiency (serum 25(OH)D level < 30 ng/ml). There were no cases of vitamin D toxicity following vitamin D replacement. Median follow-up vitamin D level was 22.7 ng/mL. No statistical difference between union rates was found between either the two consecutive cohorts or matched cohorts. CONCLUSION: This vitamin D replacement protocol was a safe treatment for hypovitaminosis D, but post hoc analysis shows there would need to be over 1200 matched patients to achieve adequate power.

Monthly Increase in Vitamin D Levels upon Supplementation with 2000 IU/Day in Healthy Volunteers: Result from "Integriamoci", a Pilot Pharmacokinetic Study.

Vitamin D (VD) is a calcium- and phosphate-controlling hormone used to treat bone disorders; yet, several other effects are progressively emerging. VD deficiency is highly prevalent worldwide, with suboptimal exposure to sunlight listed among the leading causes: oral supplementation with either cholecalciferol or calcitriol is used. However, there is a scarcity of clinical studies investigating how quickly VD concentrations can increase after supplementation. In this pilot study, the commercial supplement ImmuD3 (by Erboristeria Magentina®) was chosen as the source of VD and 2000 IU/day was administered for one month to 21 healthy volunteers that had not taken any other VD supplements in the previous 30 days. Plasma VD levels were measured through liquid chromatography coupled to tandem mass spectrometry after 7, 14, and 28 days of supplementation. We found that 95% of the participants had insufficient VD levels at baseline (<30 ng/mL; median 23.72 ng/mL; IQR 18.10-26.15), but after 28 days of supplementation, this percentage dropped to 62% (median 28.35 ng/mL; IQR 25.78-35.20). The median increase in VD level was 3.09 ng/mL (IQR 1.60-5.68) after 7 days and 8.85 ng/mL (IQR 2.85-13.97F) after 28 days. This study suggests the need for continuing VD supplementation and for measuring target level attainment.

Coronavirus disease 2019, vitamin D and kidney function.

PURPOSE OF REVIEW: The purpose of this review is to summarize the emerging studies analyzing the association between vitamin D and risk of COVID-19 infection and severity, as well as the early interventional studies investigating the protective effect of vitamin D supplementation against COVID-19. RECENT FINDINGS: Studies investigating the association between vitamin D levels and risk of COVID-19 infection and risk of severe disease and mortality among those infected have yielded mixed results. Thus far, the majority of studies investigating the association between vitamin D and COVID-19 have been observational and rely on vitamin D levels obtained at the time of admission, limiting causal inference. Currently, clinical trials assessing the effects of vitamin D supplementation in individuals with COVID-19 infection are extremely limited. Randomized, interventional trials may offer more clarity on the protective effects of vitamin D against COVID-19 infection and outcomes. SUMMARY: Decreased levels of vitamin D may amplify the inflammatory effects of COVID-19 infection, yet, data regarding the mortality benefits of vitamin D supplementation in COVID-19-infected individuals are still limited. Current observational data provides the impetus for future studies to including randomized controlled trials to determine whether vitamin D supplementation in COVID-19-infected individuals with kidney disease can improve mortality outcomes.

Metabolic effects of cholecalciferol supplementation in patients with calcium nephrolithiasis and vitamin D deficiency.

INTRODUCTION: In this paper, we investigated whether cholecalciferol supplementation may increase the risk of stone recurrence in patients with calcium nephrolithiasis and Vitamin D deficiency. METHODS: Thirty-three stone formers (56 ± 17 years old, 12 males) with 25(OH)D < 20 ng/mL were considered. Calcium excretion and urine supersaturation with calcium oxalate (ßCaOx) and brushite (ßbsh) were evaluated, both before and after cholecalciferol supplementation. Values of ß > 1 mean supersaturation. Cholecalciferol was prescribed as oral bolus of 100,000-200,000 IU, followed by weekly (5000-10,000 IU) or monthly (25,000-50,000 IU) doses. Calcium intake varied between 800 and 1000 mg/day. In urine, total nitrogen (TNE) was taken as an index of protein intake, sodium as a marker of dietary intake, and net acid excretion (NAE) as an index of acid-base balance. RESULTS: TNE, sodium, and NAE did not change during the study (p = ns). Compared to baseline values, after cholecalciferol, both serum calcium and phosphate did not vary (p = ns); 25(OH)D increased from 11.8 ± 5.5 to 40.2 ± 12.2 ng/mL (p < 0.01); 1.25(OH)2D increased from 41.6 ± 17.6 to 54 ± 16 pg/mL (p < 0.01); PTH decreased from 75 ± 27.2 to 56.7 ± 21.1 pg/mL (p < 0.01); urinary calcium increased from 2.7 ± 1.5 to 3.6 ± 1.6 mg/Kg b.w. (p < 0.01); ßbsh increased from 0.9 ± 0.7 to 1.3 ± 1.3 (p = 0.02); whereas ßCaOx varied but not significantly. Before cholecalciferol supplementation, 6/33 patients were hypercalciuric (i.e., urine Ca ≥ 4 mg/Kg b.w.) and increased to 13/33 after cholecalciferol supplementation (pX2 = 0.03). CONCLUSIONS: Cholecalciferol supplementation may increase calcium excretion, or reveal an underlying condition of absorptive hypercalciuria. This may increase both urine supersaturation with calcium salts and stone-forming risk.

Vitamin D3 reduces risk of cardiovascular and liver diseases by lowering homocysteine levels: double-blinded, randomised, placebo-controlled trial.

The objective of this study was to evaluate the effect of vitamin D3 on total homocysteine (tHcy) and C-reactive protein (CRP) levels and liver and kidney function tests in overweight women with vitamin D deficiency. Therefore, a randomised, double-blind placebo, controlled clinical trial was conducted on 100 eligible women. Subjects were randomly divided into two groups: the placebo (n 50) and the vitamin D (n 50) which received 1250 µg vitamin D3 per week for 2 months. The participants' 25-hydroxyvitamin D (25(OH)D), tHcy, CRP, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine and estimated glomerular filtration rate (eGFR) were measured and compared before and after treatment. Results showed that the tHcy, CRP, AST, ALT and eGFR levels after the 2nd month of vitamin D3 intervention were significantly (P < 0·001) decreased and the 25(OH)D, urea and creatinine levels were significantly (P < 0·001) increased in the treatment group. In the placebo group, no significant changes were identified throughout the follow-up period. In conclusion, vitamin D3 intervention with a treatment dose of 1250 µg/week for at least 2 months may help in lowering Hcy and CRP levels and may improve liver function tests, which in turn might help in minimising the risk of CVD and liver diseases among overweight women but negatively affect kidney function.

Nutrition and the Covid-19 pandemic: Three factors with high impact on community health.

AIMS: In the course of the COVID-19 pandemic, multiple suggestions have been delivered through websites and social media referring to natural substances and various kinds of supplements with thaumaturgical properties in preventing and/or fighting the coronavirus infection. Indeed, there is no clinical trial evidence that a dietary or pharmacological supplementation of any particular substance will increase the effectiveness of the immune defences. There are however three nutritional issues that deserve special attention under the present circumstances, namely vitamin D deficiency, excess salt intake and inappropriate alcohol consumption. Here is a short review of the current knowledge about the possible role of these factors in the immunity defence system and their potential impact on the modulation of the immune response to SARS-COV2 infection. DATA SYNTHESIS: For all of these factors there is convincing evidence of an impact on the immune defence structure and function. In the absence of RCT demonstration that increased ingestion of any given substance may confer protection against the new enemy, special attention to correction of these three nutritional criticisms is certainly warranted at the time of COVID pandemic. CONCLUSIONS: We propose that the inappropriate intake of salt and alcohol and the risk of inadequate vitamin D status should be object of screening, in particular in subjects at high mortality risk from SARS-COV 2 infection, such as institutionalised elderly subjects and all those affected by predisposing conditions.

Vitamin D status and outcomes for hospitalised older patients with COVID-19.

PURPOSE: Older adults are more likely to be vitamin D deficient. The aim of the study was to determine whether these patients have worse outcomes with COVID-19. METHODS: We conducted a prospective cohort study between 1 March and 30 April 2020 to assess the importance of vitamin D deficiency in older patients with COVID-19. The cohort consisted of patients aged ≥65 years presenting with symptoms consistent with COVID-19 (n=105). All patients were tested for serum 25-hydroxyvitamin D (25(OH)D) levels during acute illness. Diagnosis of COVID-19 was confirmed via viral reverse transcriptase PCR swab or supporting radiological evidence. COVID-19-positive arm (n=70) was sub-divided into vitamin D-deficient (≤30 nmol/L) (n=39) and -replete groups (n=35). Subgroups were assessed for disease severity using biochemical, radiological and clinical markers. Primary outcome was in-hospital mortality. Secondary outcomes were laboratory features of cytokine storm, thoracic imaging changes and requirement of non-invasive ventilation (NIV). RESULTS: COVID-19-positive arm demonstrated lower median serum 25(OH)D level of 27 nmol/L (IQR=20-47 nmol/L) compared with COVID-19-negative arm, with median level of 52 nmol/L (IQR=31.5-71.5 nmol/L) (p value=0.0008). Among patients with vitamin D deficiency, there was higher peak D-dimer level (1914.00 µgFEU/L vs 1268.00 µgFEU/L) (p=0.034) and higher incidence of NIV support and high dependency unit admission (30.77% vs 9.68%) (p=0.042). No increased mortality was observed between groups. CONCLUSION: Older adults with vitamin D deficiency and COVID-19 may demonstrate worse morbidity outcomes. Vitamin D status may be a useful prognosticator.

The association between vitamin D deficiency and hospitalization outcomes in pediatric patients with sickle cell disease.

BACKGROUND: While there is a known association between low vitamin D levels and increased chronic pain in patients with Sickle Cell Disease (SCD), there are no reported studies evaluating the relationship of vitamin D levels and hospitalization outcomes in this population. The aim of this study was to assess this relationship with hospitalization outcomes defined as the number of emergency room (ER) visits, hospital admissions for pain crisis, and length of hospital stay. DESIGN: A retrospective chart review of all pediatric patients with SCD (1-21 years old) was performed from January 2015 to January 2016 in an urban-based hospital setting (n = 134). Those with at least one reported Vitamin D level who maintained follow up during the time studied were enrolled (n = 90). Patient hospitalizations rates were compared between vitamin D deficiency (<20 ng/ml) and sufficiency (>20 ng/ml). RESULTS: Patients with both SCD and vitamin D deficiency were more likely to have at least one Emergency Room visit (p < 0.01), at least one admission for pain crisis (p < 0.01), and a longer length of admission (p < 0.0001) when compared to patients with SCD and sufficient vitamin D levels. CONCLUSION: There is a significant association between vitamin D levels of <20 ng/ml and the number of ER visits, hospital admissions for pain crisis, and length of stay in patients with SCD. Further research is required to assess if correcting vitamin D levels may improve hospitalization outcomes in this population.

Vitamin D for the older patient: from hype to hope?

PURPOSE OF REVIEW: The review critically appraises the most recent and important meta-analyses that have assessed the effect of vitamin D supplementation on bone health in the older population. RECENT FINDINGS: Vitamin D status is generally lower in study participants with bone wasting. However, studies on the effects of vitamin D supplementation on bone health, summarized in different meta-analyses, have provided conflicting results, likely because of the heterogeneity between studies. Interventional studies performed using more physiological doses of vitamin D (i.e. avoiding very large, nonphysiological doses) or in study participants with low vitamin D status have provided more beneficial effects on bone health. SUMMARY: Meta-analyses assessing the impact of vitamin D in the treatment of osteoporosis are heterogeneous in their conception or their results and sometimes have included inappropriate studies to answer the useful research question for the clinician, making the interpretation and the clinical use of these conflicting meta-analyses quite difficult.

Vitamin D status and supplementation impacts on skeletal muscle function: comparisons between young athletes and older adults.

PURPOSE OF REVIEW: The present narrative review analyzes emerging research implicating vitamin D status and supplementation with skeletal muscle homeostasis and functions in two distinct segments of the adult population: young athletes and older adults. RECENT FINDINGS: Vitamin D deficiency compromises multiple indices of muscle function in young athletes and older adults. A variety of vitamin D3 (cholecalciferol) supplementation regimens may transition young athletes and older adults from deficient or inadequate to adequate vitamin D status. Vitamin D supplementation, used to treat a vitamin D deficiency, but not necessarily an inadequacy, promotes muscle anabolism in older adults. For both young athletes and older adults, vitamin D supplementation, which transitions them from inadequate to adequate vitamin D status, may not beneficially affect measures of muscle strength and power, or physical performance. Also, when vitamin D status is adequate, vitamin D supplementation to further increase serum 25(OH)D concentrations does not seem to confer additional benefits to muscle strength and power and physical performance. SUMMARY: The impacts of vitamin D status and supplementation on skeletal muscle homeostasis and functions seem comparable in young athletes who strive to maximize physical performance and older adults who seek to attenuate muscle mass and physical performance declines.

Protocol of the VICTORIA study: personalized vitamin D supplementation for reducing or preventing fatigue and enhancing quality of life of patients with colorectal tumor - randomized intervention trial.

BACKGROUND: Cancer-related fatigue represents one major cause of reduced quality of life in cancer patients and can seriously affect the physical, emotional, and cognitive functioning impeding coping with the disease. Options for effective treatment of cancer-related fatigue are limited, consisting only of non-pharmacologic interventions like physical activity, psychosocial, and mind-body interventions. Recent evidence suggests that vitamin D3 supplementation might alleviate cancer-related fatigue. However, confirmation in a randomized controlled trial is needed. METHODS: In this multicenter, randomized, double-blind, placebo-controlled trial, 456 colorectal cancer (CRC) patients aged 18 years and older are being recruited in three German rehabilitation clinics. Study inclusion requires hospitalization of at least 3 weeks at such a clinic, a diagnosis of non-metastatic CRC (stage I-III), surgical removal of the tumor within the past 9 months, and season-adapted vitamin D insufficiency or deficiency. Eligible patients are randomly assigned to a personalized regimen of vitamin D3 or placebo for 12 weeks. In the intervention group, a loading dose of 20,000 or 40,000 IU vitamin D3 will be administered daily during the first 11 days, followed by a maintenance dose of 2000 IU daily. Patients will complete questionnaires for secondary outcomes (fatigue subdomains, quality of life and subdomains, depression, functional well-being, and infection frequency). Blood and urine samples will be collected for analyses of safety parameters (hypervitaminosis D, hypercalcemia, hypercalciuria, and renal impairment) and efficacy biomarkers (25-hydroxyvitamin D, HbA1c, white blood cell count, leukocyte subtype counts, serum C-reactive protein, uric acid, creatinine, triglycerides, total, low- and high-density lipoprotein cholesterol). DISCUSSION: This trial tests whether a personalized vitamin D3 dosing regimen reduces or prevents fatigue among non-metastatic CRC patients by treating the underlying vitamin D deficiency/insufficiency. If efficacy can be confirmed, personalized vitamin D3 supplementation could be used as a tertiary prevention measure in addition to non-pharmacological treatments of cancer-related fatigue in CRC patients. We expect to detect an effect of vitamin D3 supplementation on secondary outcomes like quality of life, depression, functional well-being, infections, inflammatory biomarkers, diabetes mellitus, and dyslipidemia. TRIAL REGISTRATION: European Clinical Trials Database: EudraCT-No: 2019-000502-30, January 21, 2019; German Clinical Trials Register (DRKS): DRKS00019907 , April 30, 2019.

Vitamin deficiencies in pediatric eosinophilic esophagitis: A systematic review.

BACKGROUND: Nutritional deficiencies are seen in patients with food allergy. Low vitamin D levels have been found in patients with atopic conditions. Eosinophilic esophagitis (EoE) is a chronic immune antigen-mediated disease found to be highly associated in patients with atopic disease and treated with dietary elimination with recommendations to utilize a dietician to prevent nutritional deficiencies. Nonetheless, the relationship between EoE and vitamin deficiency remains unclear. We aimed to systematically review the evidence to support a possible association between vitamin deficiency and eosinophilic esophagitis. METHODS: Electronic searches were performed with keywords relating to EoE and vitamins among pediatric patients in MEDLINE, EMBASE, and The Cochrane Library. Summary estimates were calculated. Citations were reviewed against pre-defined criteria. (Inclusion: human subjects, aged 0-18, with eosinophilic esophagitis. Exclusion: adults over 18 years, non-English papers). RESULTS: The search yielded 1707 studies. Five of these studies with a total of 137 pediatric patients were included in the systematic review. Outcome measures were assessed at different points in EoE treatment across studies. The single common outcome measure across all included studies was vitamin D. Reported prevalence of low vitamin D varied in these studies (0%-52%). Vitamin D levels of children with EoE both pre- and post-intervention were low. CONCLUSIONS: There is limited published literature on vitamin deficiencies associated with EoE both pre- and post-intervention. The limited data on vitamin D suggest that insufficiency or deficiency may be present in these patients, but it remains unclear whether deficiency is caused by diet. More prospective, well-defined studies, in addition to routine reporting on dietary intake and nutritional status, are needed to make any conclusions or recommendations for screening.

'Scientific Strabismus' or two related pandemics: coronavirus disease and vitamin D deficiency.

The WHO has announced the novel coronavirus disease (COVID-19) outbreak to be a global pandemic. The distribution of community outbreaks shows seasonal patterns along certain latitude, temperature and humidity, that is, similar to the behaviour of seasonal viral respiratory tract infections. COVID-19 displays significant spread in northern mid-latitude countries with an average temperature of 5­11°C and low humidity. Vitamin D deficiency has also been described as pandemic, especially in Europe. Regardless of age, ethnicity and latitude, recent data showed that 40 % of Europeans are vitamin D deficient (25-hydroxyvitamin D (25(OH)D) levels <50 nmol/l), and 13 % are severely deficient (25(OH)D < 30 nmol/l). A quadratic relationship was found between the prevalences of vitamin D deficiency in most commonly affected countries by COVID-19 and the latitudes. Vitamin D deficiency is more common in the subtropical and mid-latitude countries than the tropical and high-latitude countries. The most commonly affected countries with severe vitamin D deficiency are from the subtropical (Saudi Arabia 46 %; Qatar 46 %; Iran 33·4 %; Chile 26·4 %) and mid-latitude (France 27·3 %; Portugal 21·2 %; Austria 19·3 %) regions. Severe vitamin D deficiency was found to be nearly 0 % in some high-latitude countries (e.g. Norway, Finland, Sweden, Denmark and Netherlands). Accordingly, we would like to call attention to the possible association between severe vitamin D deficiency and mortality pertaining to COVID-19. Given its rare side effects and relatively wide safety, prophylactic vitamin D supplementation and/or food fortification might reasonably serve as a very convenient adjuvant therapy for these two worldwide public health problems alike.

Vitamin D supplementation for sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is a genetic chronic haemolytic and pro-inflammatory disorder. With increased catabolism and deficits in energy and nutrient intake, individuals with SCD suffer multiple macro- and micro-nutritional deficiencies, including vitamin D deficiency. This is an update of a previous review. OBJECTIVES: To investigate the effects of vitamin D supplementation in children and adults with SCD and to compare different dose regimens. To determine the effects of vitamin D supplementation on general health (e.g. growth status and health-related quality of life), on musculoskeletal health (including bone mineral density, pain crises, bone fracture and muscle health), on respiratory health (including lung function, acute chest syndrome, acute exacerbation of asthma and respiratory infections) and the safety of vitamin D supplementation. SEARCH METHODS: We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 19 March 2020. We also searched database such as PubMed, clinical trial registries and the reference lists of relevant articles and reviews. Date of last search: 14 January 2020. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs comparing oral administration of any form of vitamin D supplementation at any dose and for any duration to another type or dose of vitamin D or placebo or no supplementation in people with SCD, of all ages, gender, and phenotypes. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data and assessed the risk of bias of the included studies. They used the GRADE guidelines to assess the quality of the evidence. MAIN RESULTS: Vitamin D versus placebo One double-blind RCT (n = 39) compared oral vitamin D3 (cholecalciferol) supplementation (20 participants) to placebo (19 participants) for six weeks. Only 25 participants completed the full six months of follow-up. The study had a high risk of bias due to incomplete outcome data, but a low risk of bias for randomisation, allocation concealment, blinding (of participants, personnel and outcome assessors) and selective outcome reporting; and an unclear risk of other biases. Vitamin D supplementation probably led to higher serum 25(OH)D levels at eight weeks, mean difference (MD) 29.79 (95% confidence interval (CI) 26.63 to 32.95); at 16 weeks, MD 12.67 (95% CI 10.43 to 14.90); and at 24 weeks, MD 15.52 (95% CI 13.50 to 17.54) (moderate-quality evidence). There was little or no difference in adverse events (tingling of lips or hands) between the vitamin D and placebo groups, risk ratio 3.16 (95% CI 0.14 to 72.84) (low-quality evidence). Vitamin D supplementation probably caused fewer pain days compared to the placebo group at eight weeks, MD -10.00 (95% CI -16.47 to -3.53) (low-quality evidence), but probably led to a lower (worse) health-related quality of life score (change from baseline in physical functioning PedsQL scores); at both 16 weeks, MD -12.56 (95% CI -16.44 to -8.69) and 24 weeks, MD -12.59 (95% CI -17.43 to -7.76), although this may not be the case at eight weeks (low-quality evidence). Vitamin D supplementation regimens compared Two double-blind RCTs (83 participants) compared different regimens of vitamin D. One RCT (n = 62) compared oral vitamin D3 7000 IU/day to 4000 IU/day for 12 weeks, while the second RCT (n = 21) compared oral vitamin D3 100,000 IU/month to 12,000 IU/month for 24 months. Both RCTs had low risk of bias for blinding (of participants, personnel and outcome assessors) and incomplete outcome data, but the risk of selective outcome reporting bias was high. The bias from randomisation and allocation concealment was low in one study but not in the second. There was an unclear risk of other biases. When comparing oral vitamin D 100,000 IU/month to 12,000 IU/month, the higher dose may have resulted in higher serum 25(OH)D levels at one year, MD 16.40 (95% CI 12.59 to 20.21) and at two years, MD 18.96 (95% CI 15.20 to 22.72) (low-quality evidence). There was little or no difference in adverse events between doses (low-quality evidence). There were more episodes of acute chest syndrome in the high-dose group, at one year, MD 0.27 (95% CI 0.02 to 0.52) but there was little or no difference at two years, MD 0.09 (95% CI -0.04 to 0.22) (moderate-quality evidence). At one year and two years there was also little or no difference between the doses in the presence of pain (moderate-quality evidence) or forced expiratory volume in one second % predicted. However, the high-dose group had lower values for % predicted forced vital capacity at both one and two years, MD -7.20% predicted (95% CI -14.15 to -0.25) and MD -7.10% predicted (95% CI -14.03 to -0.17), respectively. There were little or no differences between dose regimens in the muscle health of either hand or the dominant hand. The study comparing oral vitamin D3 7000 IU/day to 4000 IU/day (21 participants) did not provide data for analysis, but median serum 25(OH)D levels were reported to be lower in the low-dose group at both six and 12 weeks. At 12 weeks the median serum parathyroid hormone level was lower in the high-dose group. AUTHORS' CONCLUSIONS: We included three RCTs of varying quality. We consider that the current evidence presented in this review is not of sufficient quality to guide clinical practice. Until further evidence becomes available, clinicians should consider the relevant existing guidelines for vitamin D supplementation and dietary reference intakes for calcium and vitamin D. Well-designed RCTs of parallel design, are required to determine the effects and the safety of vitamin D supplementation as well as to assess the relative benefits of different doses in children and adults with SCD.

Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children.

BACKGROUND: Nutritional rickets is a disease which affects children, especially in low- and middle-income countries. It causes problems such as skeletal deformities and impaired growth. The most common cause of nutritional rickets is vitamin D deficiency. Vitamin D administered with or without calcium is commonly regarded as the mainstay of treatment. In some sunny countries, however, where children are believed to have adequate vitamin D production from exposure to ultraviolet light, but who are deficient in calcium due to low dietary intake, calcium alone has also been used in the treatment of nutritional rickets. Therefore, it is important to compare the effects of vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children living in different settings. OBJECTIVES: To assess the effects of vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children. SEARCH METHODS: We searched CENTRAL, MEDLINE, LILACS, WHO ICTRP Search Portal and ClinicalTrials.gov. The date of the last search of all databases was 25 July 2019. We applied no language restrictions. SELECTION CRITERIA: We included randomised controlled trials (RCT) involving children aged 0 to 18 years with nutritional rickets which compared treatment with vitamin D, calcium or a combination of vitamin D and calcium. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the title and abstracts of all studies, extracted data and assessed the risk of bias of included studies. We resolved any disagreements by consensus or recourse to a third review author. We conducted meta-analyses for the outcomes reported by study authors. For dichotomous outcomes, we calculated the risk ratio (RR) and 95% confidence interval (CI) and, for continuous outcomes, we calculated mean differences (MD) with 95% CIs. We assessed the certainty of the evidence of the included studies using GRADE. MAIN RESULTS: We identified 4562 studies; of these, we included four RCTs with 286 participants. The studies compared two or more of the following: vitamin D, calcium or vitamin D plus calcium. The number of participants randomised to receive vitamin D was 64, calcium was 102 and vitamin D plus calcium was 120. Two studies were conducted in India and two were conducted in Nigeria. None of the included studies had a low risk of bias in all domains. Three studies had a high risk of bias in at least one domain. The age of the participants ranged between six months and 14 years. The duration of follow-up ranged between 12 weeks and 24 weeks. Two studies compared vitamin D to calcium. There is low-certainty evidence that, at 24 weeks' follow-up, calcium alone improved the healing of rickets compared to vitamin D alone (RR 3.26, 95% CI 1.59 to 6.69; P = 0.001; 1 study, 71 participants). Comparing vitamin D to calcium showed no firm evidence of an advantage or disadvantage in reducing morbidity (fractures) (RR 0.27, 95% CI 0.03 to 2.32; P = 0.23; 1 study, 71 participants; very low-certainty evidence). Adverse events were not reported. Two studies compared vitamin D plus calcium to vitamin D at 12 or 24 weeks. Vitamin D plus calcium improved healing of rickets compared to vitamin D alone at 24 weeks' follow-up (RR 3.06, 95% CI 1.49 to 6.29; P = 0.002; 1 study, 75 participants; low-certainty evidence). There is no conclusive evidence in favour of either intervention for reducing morbidity (fractures) (RR 0.24, 95% CI 0.03 to 2.08; P = 0.20; 1 study, 71 participants; very low-certainty evidence) or adverse events (RR 4.76, 95% CI 0.24 to 93.19; P = 0.30; 1 study, 39 participants; very low-certainty evidence). All four included studies compared vitamin D plus calcium to calcium at different follow-up times. There is no conclusive evidence on whether vitamin D plus calcium in comparison to calcium alone improved healing of rickets at 24 weeks' follow-up (RR 1.17, 95% CI 0.72 to 1.90; P = 0.53; 2 studies, 140 participants; very low-certainty evidence). Evidence is also inconclusive for morbidity (fractures) (RR 0.89, 95% CI 0.06 to 13.76; P = 0.94; 1 study, 72 participants; very low-certainty evidence) and adverse events (RR 4.29, 0.22 to 83.57; P = 0.34; 1 study, 37 participants; very low-certainty evidence). Most of the evidence in the review is low or very low certainty due to risk of bias, imprecision or both. None of the included studies assessed all-cause mortality, health-related quality of life or socioeconomic effects. One study assessed growth pattern but this was not measured at the time-point stipulated in the protocol of our review (one or more years after commencement of therapy). AUTHORS' CONCLUSIONS: This review provides low-certainty evidence that vitamin D plus calcium or calcium alone improve healing in children with nutritional rickets compared to vitamin D alone. We are unable to make conclusions on the effects of the interventions on adverse events or morbidity (fractures).

Vitamin D levels were significantly higher during and after lifestyle intervention in pregnancy: A randomized controlled trial.

INTRODUCTION: Vitamin D deficiency is common in pregnancy, especially in obese women. Lifestyle intervention could potentially result in higher levels of vitamin D. We therefore aimed to study the effect of lifestyle intervention during pregnancy on serum levels of 25-hydroxyvitamin D (25(OH)D). MATERIAL AND METHODS: A total of 360 obese women were randomized before gestational age 14 weeks to lifestyle intervention (diet and exercise) or routine clinical follow up (controls). Clinical outcomes and levels of 25(OH)D were determined three times: At gestational age 12-15 weeks (baseline), gestational age 28-30 weeks and 6 months postpartum. RESULTS: A total of 304 (84%) women completed the intervention study and 238 (66%) attended postpartum follow up. Vitamin D levels were similar in the two groups at baseline. At gestational age 28-30 weeks and 6 months postpartum, 25(OH)D levels were significantly higher in the intervention group than in controls (75.6 vs 66.8 nmol/L, P = 0.009) and (54.8 vs 43.1 nmol/L, P = 0.013), respectively. Concurrently, vitamin D deficiency (25-hydroxyvitamin D <50 nmol/L) was less frequent in the intervention group than in controls: 15 vs 25% (P = 0.038) at gestational age 28-30 and 45 vs 63% (P = 0.011) 6 months postpartum, respectively. CONCLUSIONS: Lifestyle intervention during pregnancy was associated with significantly increased vitamin D levels in late pregnancy and postpartum compared with controls.

Effects of Vitamin D Supplementation on General and Central Obesity: Results from 20 Randomized Controlled Trials Involving Apparently Healthy Populations.

BACKGROUND: The obesity pandemic has been paralleled by a high prevalence of vitamin D deficiency (VDD). There is growing epidemiological evidence linking low vitamin D status with obesity events. In addition, observational studies also show that obesity may increase the risk of VDD. However, there is insufficient knowledge to understand whether there is a causality between the two. Moreover, the impact of vitamin D supplementation on obesity indices has shown inconsistent outcomes. OBJECTIVE: This meta-analysis aimed to assess whether vitamin D supplementation modified general and central obesity indices in apparently healthy populations. METHODS: A systematic retrieval of relevant randomized controlled trials (RCTs) was undertaken using Pubmed, Embase, Web of Knowledge and Chinese National Knowledge Infrastructure databases. The pooled weighted mean difference (WMD) and 95% confidence intervals (CI) were used to assess the changes in body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and 25-hydroxyvitamin D (25[OH]D) from baseline. RESULTS: Twenty RCTs involving 3,153 participants reporting either BMI, WC, WHR or 25(OH)D met the inclusion criteria. When compared with placebo, vitamin D supplementation had no significant decreases in BMI (WMD = -0.09 kg/m2, 95% CI -0.19 to 0.01, p = 0.08), WC (WMD = -0.71 cm, 95% CI -1.58 to 0.16, p = 0.112) or WHR (WMD = 0.00, 95% CI -0.01 to 0.01, p = 0.749). However, in the subgroups of females, Asia region studies and intervention duration ≥6 months, a beneficial and significant reduction in BMI and WC was noted (all p < 0.026). On the other hand, pooled results showed that there was a significant increase in serum 25(OH)D levels (WMD = 13.20 ng/mL, 95% CI 9.83-16.58, p < 0.001) after vitamin D intervention. No publication bias was found in our study. CONCLUSIONS: Overall, supplementation with vitamin D produced no significant effect on the BMI, WC or WHR of healthy adults.

Associations between hypovitaminosis D and COVID-19: a narrative review.

In the search for factors affecting incidence and lethality of the current COVID-19 pandemic, recent association studies explored the possible role of vitamin D deficiency. Altogether, these studies, in most cases based on cross-sectional analyses, could not yet provide a convincing demonstration of a cause-effect relationship. In this editorial, the authors describe the scientific evidence underlying a possible role of vitamin D in the prevention and development of the pandemic, considering its immunomodulatory role and antiviral effects. They conclude that further studies are needed to (1) better explore possible associations between vitamin D deficiency and COVID-19 morbidity and lethality, and (2) assess if compensating such deficiency could avoid or mitigate the worst manifestations of COVID-19. They highlight the need for public health campaigns to promote consumption of vitamin D-rich foods and proper sunlight exposition or, when this is not possible, controlled pharmaceutical supplementation, especially in countries with high prevalence of hypovitaminosis D.

Vitamin D effects and endocrine diseases.

A lack of vitamin D has been linked to autoimmune diseases including type 1 diabetes, autoimmune thyroiditis and to obesity. The prevalence of vitamin D deficiency is higher in diabetic or obese children and patients with thyroiditis compared to healthy controls. Moreover, low vitamin D values seem to be associated with major complications and poor glycemic control, in particular in obese children. Supplementation with vitamin D, which has immune-regulatory properties, may support our therapies and improve the outcomes in different diseases. Although some studies suggest a possible role of vitamin D in the etiology of autoimmune diseases and obesity, data on supplementation benefits are inconclusive and further studies are needed. In this paper, we focus on the current evidence regarding vitamin D function in endocrine diseases and possible benefits of its supplementation in pediatric age.

[Vitamin D in adolescents: summarizing guidelines for general practice]. / Vitamine D chez les adolescents: résumé des recommandations pour la pratique Clinique.

Vitamin D plays a critical role in bone health in adolescence. Is screening and treatment of vitamin D deficiency therefore necessary at this age? Inspired by a clinical case, we try to answer this question by presenting a summary of worldwide recommendations for vitamin D in adolescents.

La vitamine D joue un rôle indispensable pour la santé osseuse des adolescents. Faut-il de ce fait dépister et traiter d'éventuelles carences en vitamine D à cet âge ? À partir d'un cas clinique, nous tentons de répondre à cette question en présentant une synthèse des recommandations disponibles dans la littérature mondiale à propos de la vitamine D chez les adolescents.