Oral intermittent vitamin D substitution: influence of pharmaceutical form and dosage frequency on medication adherence: a randomized clinical trial

Vitamin D Supplementation and the Incidence of Fractures in the Elderly Healthy Population: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Although a well-established component of bone metabolism, the efficacy and safety of vitamin D supplementation for the prevention of fractures in elderly healthy individuals is still unclear.

PURPOSE

To perform a meta-analysis comparing vitamin D supplementation with placebo and its contributions on fracture incidence.

METHODS

This meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO), under protocol CRD42023484979. We systematically searched PubMed, Embase, and Cochrane Central databases from inception to November 2023 for randomized controlled trials (RCTs) comparing vitamin D supplementation versus placebo in individuals with 60 years of age or more and without bone related medical conditions such as cancer and osteoporosis.

RESULTS

Seven RCTs with 71,899 patients were included, of whom 36,822 (51.2%) were women. There was no significant difference in total fracture incidence (RR 1.03; 95% CI 0.93-1.14; p = 0.56; I2 = 58%) between groups or subgroups. However, women had an increased risk for hip fractures (164 vs. 121 events; RR 1.34; 95% CI 1.06-1.70; p = 0.01; I2 = 0%). There was no significant difference in non-vertebral fractures, osteoporotic fractures development, or falls (RR 1.02; 95% CI 0.94-1.12; p = 0.6; I2 = 47%; RR 0.97; 95% CI 0.87-1.08; p = 0.63; I2 = 0%; RR 1.01; 95% CI 0.97-1.04; p = 0.66; I2 = 55%, respectively).

CONCLUSION

Vitamin D supplementation does not reduce the total fracture development rate in the elderly healthy population, and it may increase the incidence of hip fractures among elderly healthy women. This finding suggests refraining from prescribing high intermittent doses of vitamin D, without calcium, to individuals aged 60 or older with unknown vitamin D serum concentration or osteoporosis status and inadequate calcium intake.

Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows

The 6th International Conference, "Controversies in Vitamin D," was convened to discuss controversial topics, such as vitamin D metabolism, assessment, actions, and supplementation. Novel insights into vitamin D mechanisms of action suggest links with conditions that do not depend only on reduced solar exposure or diet intake and that can be detected with distinctive noncanonical vitamin D metabolites. Optimal 25-hydroxyvitamin D (25(OH)D) levels remain debated. Varying recommendations from different societies arise from evaluating different clinical or public health approaches. The lack of assay standardization also poses challenges in interpreting data from available studies, hindering rational data pooling and meta-analyses. Beyond the well-known skeletal features, interest in vitamin D's extraskeletal effects has led to clinical trials on cancer, cardiovascular risk, respiratory effects, autoimmune diseases, diabetes, and mortality. The initial negative results are likely due to enrollment of vitamin D-replete individuals. Subsequent post hoc analyses have suggested, nevertheless, potential benefits in reducing cancer incidence, autoimmune diseases, cardiovascular events, and diabetes. Oral administration of vitamin D is the preferred route. Parenteral administration is reserved for specific clinical situations. Cholecalciferol is favored due to safety and minimal monitoring requirements. Calcifediol may be used in certain conditions, while calcitriol should be limited to specific disorders in which the active metabolite is not readily produced in vivo. Further studies are needed to investigate vitamin D effects in relation to the different recommended 25(OH)D levels and the efficacy of the different supplementary formulations in achieving biochemical and clinical outcomes within the multifaced skeletal and extraskeletal potential effects of vitamin D.

Supplementing Vitamin D in Different Patient Groups to Reduce Deficiency

INTRODUCTION

Studies indicate a high prevalence of vitamin D deficiency in both the general population and at-risk groups. Given the association between vitamin D deficiency and various diseases, addressing this concern becomes crucial, especially in situations where routine monitoring is challenging.

MATERIALS AND METHODS

A systematic literature review of the current knowledge on vitamin D dosing in diverse at-risk populations and the application of the findings to a broader clinical perspective.

RESULTS

The reviewed studies revealed a high prevalence of vitamin D deficiency among patients with musculoskeletal disorders, systemic connective tissue diseases, corticosteroid use, endocrine and metabolic conditions, malabsorption syndromes, obesity, chronic kidney disease, cancer, and central nervous system diseases. Vitamin D deficiency was often more severe compared to the general population. Higher dosages of vitamin D beyond the recommended levels for the general population were shown to be effective in improving vitamin D status in these at-risk individuals. Additionally, some studies suggested a potential link between intermittent vitamin D administration and improved adherence.

CONCLUSION

Simplified dosing could empower clinicians to address vitamin D deficiency, particularly in high-risk populations, even without routine monitoring. Further research is needed to establish the optimal dosing regimens for specific at-risk populations.

Controlled randomized open label clinical study comparing the safety and efficacy of loading schedules in Vitamin D deficient patients

Rapidly restoring vitamin D levels to normal might be desirable in certain clinical situations. Larger doses of supplementation, have been shown to increase bone loss and the risk of falls. The optimal way to perform vitamin D loading safely and effectively is still not well elucidated. Our study was aimed to assess the safety and efficacy of two oral vitamin D loading protocols. Sixty-nine subjects with vitamin D deficiency (25OH-vitamin D (25(OH)D) < 20ng/ml) were included. Thirty-five participants received 30 000 IU of vitamin D₃ per week for 10 weeks (group Slower Loading Dose (SLD)) and thirty-four received 30 000 IU twice weekly for 5 weeks (group Moderate Loading Dose (MLD)) resulting in a loading dose of 300 000 IU for all subjects. Following this initial loading phase, both groups received 30 000 IU biweekly for 4 weeks to test whether the recommended daily vitamin D supplementation in range of 2,000 IU dose-equivalent could maintain the achieved levels. Seventy-nine percent of those subjects treated in group SLD and everyone in group MLD achieved a 25(OH)D level of 30ng/ml, which is the lower limit of the recommended normal range in Hungary. The mean increase in 25(OH)D was significantly higher in group MLD than in group SLD (38.6±1.80ng/ml vs 46,6±1.80ng/ml). No significant decrease was observed with the administration of the maintenance dose. There were no clinically significant changes in serum or urine calcium, and bone biomarkers in either group. Both protocols were found to be safe and effective, but the five-week dosing caused a significantly greater increase in 25(OH)D. A maintenance dose applied for four weeks after the loading protocol did not raise 25(OH)D levels further but maintained the achieved increase. The administration of 30 000 IU of vitamin D₃ twice weekly for five weeks is a rapid, effective and safe way to treat vitamin D deficiency in vitamin D deficient patients.

Vitamin D, Menopausal Health and COVID-19: Critical Appraisal of Current Data

Inconsistency exists across studies conducted in postmenopausal women regarding the effect of vitamin D deficiency (VDD) and supplementation on several aspects of menopausal health, such as fractures, vasomotor symptomatology, cardiovascular disease (CVD), cancer and infections, including coronavirus disease 2019 (COVID-19). The aim of this review is to critically summarize the evidence provided by observational studies and randomized controlled trials (RCTs) of vitamin D supplementation in postmenopausal women with VDD. Observational studies have found that VDD is associated with an increased risk of falls and fractures after the menopause. VDD also has a negative effect on menopausal symptomatology. VDD, especially its severe form, is associated with an increased risk of CVD risk factors and CVD events. VDD is associated with increased risk and mortality from several cancer types and risk of infections. The evidence from RCTs regarding the effect of vitamin D supplementation on falls, fractures, menopausal symptoms, cardiovascular disease, cancer and infections is not robust. Thus, skeletal health may benefit only when vitamin D is co-administered with calcium, especially in those ≥70 years old and with severe VDD. There is no evidence of a favorable effect on menopausal symptoms or risk of CVD or cancer, except for a modest reduction in cancer-related mortality. Inconsistency still exists regarding its effect on infection risk, disease severity and mortality due to COVID-19.

Clinical Practice in the Prevention, Diagnosis and Treatment of Vitamin D Deficiency: A Central and Eastern European Expert Consensus Statement

Vitamin D deficiency has a high worldwide prevalence, but actions to improve this public health problem are challenged by the heterogeneity of nutritional and clinical vitamin D guidelines, with respect to the diagnosis and treatment of vitamin D deficiency. We aimed to address this issue by providing respective recommendations for adults, developed by a European expert panel, using the Delphi method to reach consensus. Increasing the awareness of vitamin D deficiency and efforts to harmonize vitamin D guidelines should be pursued. We argue against a general screening for vitamin D deficiency but suggest 25-hydroxyvitamin D (25(OH)D) testing in certain risk groups. We recommend a vitamin D supplementation dose of 800 to 2000 international units (IU) per day for adults who want to ensure a sufficient vitamin D status. These doses are also recommended for the treatment of vitamin D deficiency, but higher vitamin D doses (e.g., 6000 IU per day) may be used for the first 4 to 12 weeks of treatment if a rapid correction of vitamin D deficiency is clinically indicated before continuing, with a maintenance dose of 800 to 2000 IU per day. Treatment success may be evaluated after at least 6 to 12 weeks in certain risk groups (e.g., patients with malabsorption syndromes) by measurement of serum 25(OH)D, with the aim to target concentrations of 30 to 50 ng/mL (75 to 125 nmol/L).

Vitamin D oral intermittent treatment (DO IT) study, a randomized clinical trial with individual loading regimen

Comparison of several regimens of oral vitamin D including an individually calculated loading regimen with the aim of achieving serum values > 75 nmol/l. Interventional, randomized, 3-arm study in vitamin D-deficient outpatients. Participants were allocated to supplementation of 24,000 IU vitamin D monthly over three months, using either a monthly drinking solution (Vi-De 3) or capsule (D3 VitaCaps), or an individualized loading regimen with the capsules taken weekly. For the loading regimen, the cumulative dose was calculated according to baseline 25-hydroxy-vitamin D (25(OH)D) serum value and body weight. Main inclusion criteria were age ≥ 18 years and 25(OH)D serum concentration < 50 nmol/l. The primary outcome was 25(OH)D serum concentration one week after treatment termination. Secondary endpoints were patient's preferences and adverse events. Full datasets were obtained from 52 patients. Mean 25(OH)D values were statistically significant higher after a loading regimen compared to a monthly administration of 24,000 IU vitamin D (76.4 ± 15.8 vs 61.4 ± 10.8 nmol/l; p < 0.01). All patients treated with the loading regimen reached sufficient 25(OH)D values > 50 nmol/l. Serum 25(OH)D values > 75 nmol/l were observed more frequently in patients taking the loading regimen (47% vs 11% drinking solution vs 12% capsules). Vitamin D-related adverse effects did not occur in any treatment groups. Capsules were preferred by 88.5% of the patients. Compared to treatments with monthly intake of 24,000 IU vitamin D, the intake of an individually calculated weekly loading regimen was able to raise serum concentrations > 50 nmol/l in all cases within a safe range.

Vitamin D and Lipid Profiles in Postmenopausal Women: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

Background and Aim: It is known that hyperlipidemia and low vitamin D level are risk factors associated with cardiovascular disease (CVD). However, the effect of vitamin D administration on lipid profiles in postmenopausal women remains unclear. This study aims to evaluate the effect of vitamin D on lipid profiles in postmenopausal women based on meta-analysis and systemic review. Methods: The literature search was performed in multiple databases (Scopus, PubMed/Medline, Web of Science, and Embase) from 1997 to 2021. The statistical analysis was performed using the Stata software version 14 (Stata Corp. College Station, Texas, United States). The effects of vitamin D administration of the lipid profiles, including Triacylglycerol (TG), LDL-Cholesterol (LDL-C), HDL-Cholesterol (HDL-C), and Total Cholesterol (TC) were evaluated by the Der Simonian and Laird random effects model. The weighted mean difference (WMD) and 95% confidence intervals (CI) were calculated. Results: The level of TG changed significantly by -3.76 mg/dl (CI: -6.12 to -1.39, p = 0.004) and HDL-C by 0.48 mg/dl (CI: -0.80 to -0.15, p = 0.004) in vitamin D administration group [11 eligible trials (placebo = 505 participants, vitamin D intervention = 604 participants)] compared to the control group in the postmenopausal women. Taking into account this comparison between groups, in contrast, the level of LDL-Cholesterol (LDL-C) (WMD: 0.73 mg/dl, 95% CI: -1.88, 3.36, p = 0.583) and TC (WMD: 0.689 mg/dl, CI: -3.059 to 4.438, p = 0.719) did not change significantly. Conclusion: In conclusion, the vitamin D administration in postmenopausal women, decreased the concentrations of TG, and HDL-C, but have no effects on LDL-C and TC.