A multistage double-blind placebo-controlled study to assess the safety and efficacy of transdermal vitamin D phosphate supplementation (TransVitD)

BACKGROUND

Lifestyle changes have meant that it is problematic for many people across the globe to maintain adequate vitamin D concentrations. As UV-catalysed production in the skin, which uses vitamin D-binding protein to facilitate systemic absorption, is the primary source of vitamin D, it is questionable if oral supplementation of this vitamin is the optimal means to replace it. However, supplementing an oil-soluble vitamin via the skin is problematic as it gets stuck in the stratum corneum after topical application. This clinical study will test if a new vitamin D ester, vitamin D phosphate, which is more water-soluble compared to vitamin D, administered via a transdermal patch, can be used to improve vitamin D status.

METHOD

This is a two-part study comprising a dose-escalation with the vitamin D phosphate transdermal patch followed by a randomised, double-blind, placebo-controlled, multiarmed, multistage clinical trial. It is a single-centred, 12-week study that will enrol a maximum of 100 participants. The dose escalation study will monitor safety and tolerability using serum calcium and 25(OH)D3 levels. The blinded, randomised trial will test different dose frequencies for 4 weeks compared to a placebo. Then, after an interim analysis, the best dosing frequency will be assessed against a placebo. The primary outcome for the multistage clinical study will be the percentage change in 25(OH)D3 concentration in the serum (ng/mL) at weeks 4 and 8 compared to baseline. The secondary outcome measures include percentage change in serum vitamin D-binding protein levels, skin interstitial fluid biomarker concentrations, and nail appearance after 4 and 8 weeks compared to baseline.

DISCUSSION

This study will determine if a vitamin D phosphate transdermal patch can improve vitamin D status. In addition, it could provide a better understanding of how vitamin D is absorbed directly into the skin after application by measuring the serum vitamin D-binding protein and skin biomarker responses to transdermal supplementation.

TRIAL REGISTRATION

Clinical Trials.gov NCT06098846, registered on 23rd October 2023.

Can the use of vitamin D-fortified sunscreen cream be the solution to the vitamin D deficiency pandemic?

Current approaches to vitamin D supplementation are generally limited to its oral intake. In this experimental study, the effects of applying vitamin D-fortified sunscreen creams to the skin on the absorption, and therefore levels of serum vitamin D metabolites were investigated. Forty 8-week-old male Wistar Albino rats were used in the study. Eight rats (Group B) were sacrificed to determine the baseline values of biochemical parameters. The remaining 32 rats were randomly divided into 4 equal groups as follows: Group S, only the back skin of the rats were shaved; Group SD, only vitamin D3 diluted with sunflower oil was applied to the shaved area; Group SC, only sunscreen cream was applied to the shaved area; and Group SDC, sunscreen cream fortified with vitamin D3 was applied to the shaved area. Serum 25(OH)D3 and 24,25(OH)2D3 levels were determined at the end of 8 weeks. Mean (± SD) serum 25(OH)D3 levels of groups B, S, SD, SC, and SDC were determined as 17.7 ± 5.7, 13.5 ± 3.1, 54.1 ± 13.0, 19.6 ± 2.7, 67.2 ± 16.5 ng/mL, respectively. There were statistically significant differences in serum 25(OH)D3 values between groups S and SD (p < 0.001) and between groups SC and SDC (p = 0.002). A positive correlation was found between serum 25(OH)D3 and 24,25(OH)2D3 parameters (r = 0.772; p < 0.001). With this study, it was concluded that vitamin D-fortified sunscreen cream increases serum vitamin D levels by exerting transdermal activity. Further studies are required to confirm this observations.

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.

Novel Therapeutic Hybrid Systems Using Hydrogels and Nanotechnology: A Focus on Nanoemulgels for the Treatment of Skin Diseases

Topical and transdermal drug delivery are advantageous administration routes, especially when treating diseases and conditions with a skin etiology. Nevertheless, conventional dosage forms often lead to low therapeutic efficacy, safety issues, and patient noncompliance. To tackle these issues, novel topical and transdermal platforms involving nanotechnology have been developed. This review focuses on the latest advances regarding the development of nanoemulgels for skin application, encapsulating a wide variety of molecules, including already marketed drugs (miconazole, ketoconazole, fusidic acid, imiquimod, meloxicam), repurposed marketed drugs (atorvastatin, omeprazole, leflunomide), natural-derived compounds (eucalyptol, naringenin, thymoquinone, curcumin, chrysin, brucine, capsaicin), and other synthetic molecules (ebselen, tocotrienols, retinyl palmitate), for wound healing, skin and skin appendage infections, skin inflammatory diseases, skin cancer, neuropathy, or anti-aging purposes. Developed formulations revealed adequate droplet size, PDI, viscosity, spreadability, pH, stability, drug release, and drug permeation and/or retention capacity, having more advantageous characteristics than current marketed formulations. In vitro and/or in vivo studies established the safety and efficacy of the developed formulations, confirming their therapeutic potential, and making them promising platforms for the replacement of current therapies, or as possible adjuvant treatments, which might someday effectively reach the market to help fight highly incident skin or systemic diseases and conditions.

Using a Topical Formulation of Vitamin D for the Treatment of Vitiligo: A Systematic Review

Vitamin D is one significant prohormone substance in human organ systems. It is a steroidal hormone produced in the skin upon exposure to UVB rays. This paper presents a systematic review of the utilization of topical vitamin D, specifically cholecalciferol, calcipotriol, and tacalcitol, in the treatment of vitiligo. It considers the role of vitamin D in stimulating the synthesis of melanin and melanogenesis, which can help with the process of repigmentation. The inclusion of calcipotriol or tacalcitol in Narrowband Ultraviolet Phototherapy (NB-UVB) has shown the potential to enhance therapeutic outcomes for vitiligo. However, their effectiveness in combination with Psoralens Long Wave Ultraviolet Radiation (PUVA) and Monochromatic Excimer Light (MEL) treatment for vitiligo is limited. In contrast, combining topical corticosteroids with vitamin D analogues has demonstrated superior efficacy in treating vitiligo compared to using vitamin D analogues alone, while also providing the added benefit of reducing corticosteroid-related adverse effects. In addition, treating stable vitiligo with topical cholecalciferol and microneedling has shown success. Future studies are needed to ascertain an efficient method of administering vitamin D topically as an anti-vitiligo agent.

Preparation and Evaluation of Vitamin D3 Supplementation as Transdermal Film-Forming Solution

Vitamin D3 is available in oral and injectable dosage forms. Interest in the transdermal route as an alternative to the oral and parenteral routes has grown recently. In this study, several film-forming solutions for the transdermal delivery of vitamin D3 were prepared. They contained 6000 IU/mL of vitamin D3 that formed a dry and acceptable film in less than 5 min after application. The formulations consisted of ethanol and acetone 80:20, and one or more of the following ingredients: Eudragit L100-55, PVP, PG, limonene, oleic acid, camphor, and menthol. Vitamin D3 release was studied from both the film-forming solution and pre-dried films using a Franz diffusion cell. The film-forming solution released a significant amount of vitamin D3 compared to the dry film, which is attributed mostly to the saturation driving force due to the evaporation of volatile solvents. In vitro permeation studies through artificial skin Strat M® membrane revealed that the cumulative amount of vitamin D3 permeated after 24 h under the experimental conditions was around 800 IU across 3.14 cm2. The cumulative permeation curve showed faster permeation in earlier stages. Young's modulus, viscosity, and pH of the formulations were determined. Most of the formulations were stable for 3 weeks.

Evaluation of the safety, tolerability and plasma vitamin D response to long-term use of patented transdermal vitamin D patches in healthy adults: a randomised parallel pilot study

Background

Vitamin D delivered transdermally may suppress hyperactivity in nociceptor pain receptors and alter pain intensity, offering a useful addition to localised pain management in varying clinical settings. Currently, little is known about long-term usage of continuous-release vitamin D patches.

Method

We conducted a randomised parallel pilot trial to evaluate safety and tolerability of daily application of patented (US8821921B2) transdermal vitamin D patches over 8 weeks and assess time-level profile of serum vitamin D. Compliance, tolerance and sun exposure were monitored daily, serum 25(OH)D measured 2-weekly and dietary intake and safety markers 4-weekly.

Results

Thirty healthy adults were randomised to two treatment groups: big patch and small patch. mean age was 36 years (20-68 years) with a 63% female to 37% male split. Patches differed in size but contained identical ingredients including 30 000 IU cholecalciferol. Physical and blood safety markers remained stable, within normal clinical parameters, and with no clinically meaningful changes throughout. Five big patch participants experienced skin irritation, which was mild and occasional for three, but continuous for two leading to patch withdrawal. There were no skin reactions in small patch group. average, serum 25(OH)D levels increased by +14 nmol/L (SD 11.63, range, -4 to 40 nmol/L) between baseline and week 8, with no significant differences between patch sizes. There was a shift in overall vitamin D status between baseline and week 8 (23% deficient (<30 nmol/L) decreasing to 0%, and normal (>50 nmol/L) increasing from 37% to 70% at week 8).

Conclusion

Based on these results, long-term (8 weeks) application of patented transdermal vitamin D patches was found to be safe. There may be minor skin tolerance issues with big patches for some, which appears to relate to patch size. Larger trials are warranted to explore the increase in vitamin D levels beyond 8 weeks.

Trial registration number

NCT04851990.

Skin as an endocrine organ: A narrative review

Skin being the largest organ of the body, is equipped with numerous functional properties. Over the past few years, intricate research into the biology of skin has led to a gamut of discoveries. Skin is now regarded as one of the most vital endocrine organs. The skin contains equivalents of the hypothalamo-pituitary-adrenal axis, hypothalamo-pituitary-thyroid axis and the appendages produce multiple hormones such as Vitamin D, sex steroids, retinoids and opioids. In this article, we will explore the role of skin as a target and source of some of the hormones of the human body, and briefly touch on the clinical applications.

An Update on Vitamin D Deficiency in the twenty-first century: nature and nurture

PURPOSE OF REVIEW

Here, we review the most up-to-date understanding of the pathogenesis, prevention and treatment of vitamin D deficient rickets in children. This will include recent advances in the genetic determinants of abnormal vitamin D metabolism, with the intention of aiding clinicians with establishing the diagnosis and implementing treatment plans for children presenting with vitamin D deficiency rickets.

RECENT FINDINGS

Vitamin D deficiency rickets is a frequently encountered, but entirely preventable, disorder of bone mineral metabolism. Risk factors for developing vitamin D deficiency rickets include inadequate exposure to sunlight, exclusive breast feeding without vitamin D supplementation and inadequate intake of vitamin D, calcium or phosphorus. Other factors that may influence the development of vitamin D deficiency and/or rickets include genetic alterations or medications that alter vitamin D metabolism.

SUMMARY

Vitamin D levels in individuals are influenced by environmental factors, as well as genetic factors. A thorough understanding of these factors is critical for the evaluation and treatment of a child presenting with rickets. There remains a great need for additional research to determine ideal vitamin D status across diverse populations, and to better understand how vitamin D status affects overall health.

Association between vitamin D3 levels and insulin resistance: a large sample cross-sectional study

Previous studies have shown that vitamin D3 may be a potential factor in insulin resistance, but the relationship between vitamin D3 and insulin resistance still remains controversial. At present, more research is needed to explore the relationship between vitamin D3 and insulin resistance. The samples from 2009 to 2018 in NHANES database were analyzed to Investigate the relationship and the potential mechanism. We performed a cross-sectional study of five periods in the NHANES database. Finally, 9298 participants were selected through strict inclusion and exclusion criteria, Multivariate logistic regression analysis and curve fitting were conducted to explore the relationship between vitamin D3 level and insulin resistance. Moreover, subgroup analysis was used to further prove the association. The results revealed that there was a strong association between vitamin D3 and insulin resistance (OR 0.82, 95% CI 0.72-0.93). However, subgroup analyses indicated that this correlation varied between individuals and races. There was a negative correlation between vitamin D3 level and insulin resistance, which provides a new proof for exploring the influencing factors of insulin resistance. More well-designed studies are still needed to further elaborate on these associations.

Vitamin D toxicity related to its physiological and unphysiological supply

Vitamin D is defined as a nutrient despite its rare occurrence in food. Vitamin D status is determined mainly by solar UV light action in skin. However, the strategy to combat vitamin D deficiency has been to increase oral intake of vitamin D in greater amounts than could be obtained from food. Persistent large intakes of vitamin D can cause hypercalcaemic toxicity. Although the amounts recommended to prevent deficiency are far less than those causing such toxicity, the possibility of other toxic actions from increased intake of vitamin D has been ignored. Animal experiments have demonstrated that moderate amounts of oral vitamin D over time result in atherosclerosis. Differences in the fate of vitamin D could explain this angiotoxicity.

Efficacy of transdermal delivery of liposomal micronutrients through body oil massage on neurodevelopmental and micronutrient deficiency status in infants: results of a randomized placebo-controlled clinical trial

BACKGROUND

Micronutrient deficiency is a known cause of adverse neurodevelopment and growth. Poor adherence to oral regimes of micronutrient supplements is a known challenge during the implementation of supplementation programs. The present study evaluates the benefits of liposomal encapsulated micronutrient fortified body oils (LMF oil) that can be used for infant body massage in terms of neurodevelopment and prevention of deficiency.

STUDY DESIGN

Double-blind randomized clinical trial.

METHODS

A total of 444 healthy infants aged 4-7 weeks were randomized to receive either LMF oil (containing iron, vitamin D, folate, and vitamin B12) or placebo oil for gentle body massage till 12 months of age. Blood samples were collected at 6 and 12 months for transferrin saturation (TSAT), hemoglobin, and 25-hydroxy vitamin (25-OH-D) levels. Mental and motor development was assessed at 12 months using developmental assessment for Indian Infants (DASII).

RESULTS

A total of 391 infants completed the study. There was no significant improvement in the hemoglobin in the intervention group at 12 months of age as compared to the placebo group [- 0.50 vs.-0.54 g%]. There was a marginally significant improvement in 25-OH-D at 12 months in the LMF oil group [+ 1.46vs.-0.18 ng/ml, p = 0.049]. In the subgroup of infants with moderate anemia, the intervention prevented the decline in hemoglobin at 12 months of age [adjusted mean change + 0.11vs.-0.51 g%, p = 0.043]. The mental or motor developmental quotients in the intervention group were not significantly different from those in the placebo group.

CONCLUSION

Use of LMF oil for prevention of nutritional deficiency did not offer significant protection against nutritional anemia but prevented vitamin D deficiency to some extent with improvement in 25-OH-D at 12 months. In the subgroup of infants with moderate anemia, the intervention prevented the decline in hemoglobin at 12 months of age. The intervention did not result in significant improvement in mental or motor development. Further evaluation with increased doses needs to be undertaken.

TRIAL REGISTRATION

CTRI no: CTRI/2017/11/010710 ; dated 30/11/2017.

Assessment of a Novel Vitamin D3 Formulation with Nanostructured Lipid Carriers for Transdermal Delivery

OBJECTIVE

Develop and assess a transdermal emulsion loaded with nanostructured lipid carriers for vitamin D3 supplementation.

METHODS

Vitamin D3 loaded nanostructured lipid carriers, produced via high shear homogenization and ultrasonication, were assessed for their particle size, distribution, morphology, zeta potential, entrapment efficiency, and cytotoxicity. They were incorporated into a transdermal vehicle, and the stability and ex vivo permeation were evaluated.

RESULTS

Spherical nanoparticles were developed with a particle size of 192.5 nm, a polydispersity index of 0.13, a zeta potential of -29.0 mV, and an entrapment efficiency of 99.75%. They were stable (particle size and distribution) for 15 days when stored in a refrigerator and for 30 days at room temperature and 32 °C. The nanoparticles decreased the drug cytotoxicity against fibroblasts, as shown by IC50 (nanoparticle: 32.48 μg mL-1; vitamin D3: 16.73 μg mL-1). The emulsion loaded with nanoparticles minimized the degradation of vitamin D3 when compared with the nanoparticle dispersion. Additionally, the emulsion provided the skin permeation of vitamin D3 following the recommended daily allowance.

CONCLUSION

To the best of our knowledge, this is the first study to use nanostructured lipid carriers for transdermal delivery of vitamin D. The developed formulation is a promising strategy to overcome the vitamin D3 variable oral bioavailability. It also represents a comfortable route of administrationd. Thus it could be beneficial for patients and clinicians. However, further studies are needed to allow the permeation of larger amounts of vitamin D3, and the combination of these nanoparticles with microneedles would be interesting.

Strategies for transdermal drug delivery against bone disorders: A preclinical and clinical update

The transdermal drug delivery system is an exceptionally safe and well-tolerable therapeutic approach that has immense potential for delivering active components against bone-related pathologies. However, its use is limited in the current clinical practices due to the low skin permeability of most active drugs in the formulation. Thus, innovations in the methodologies of skin permeation enhancement techniques are suggested to overcome this limitation. Although various transdermal drug delivery systems are studied to date, there are insufficient studies comparing the therapeutic efficacy of transdermal delivery systems to oral delivery systems. Thus, creating a decision-making dilemma between oral or transdermal therapies. Therefore, a timely review is inevitable to develop a platform for future researchers to develop next-generation transdermal drug delivery strategies against skeletal diseases that must be convenient and cost-effective for the patients with improved therapeutic efficacy. Here, we will outline the most recent strategies that can overcome the choice limitation of the drug and enhance the transdermal adsorption of various types of drugs to treat bone disorders. For the first time, in this review paper, we will highlight the preclinical and clinical studies on the different transdermal delivery methods. Thus, providing insight into the current therapeutic approaches and suggesting new directions for the advancements in transdermal drug delivery systems against bone disorders.

The efficacy of different vitamin D supplementation delivery methods on serum 25(OH)D: A randomised double-blind placebo trial

BACKGROUND

The use of vitamin D supplementation has increased due to greater recognition of widespread deficiency.

AIMS

There has been little research on the effectiveness of different delivery methods and therefore the aim of was to test the efficacy of different delivery methods on serum 25(OH)D.

METHODS

Using a randomised repeated measures double-blind placebo design (registered under ClinicalTrials.gov Identifier no. NCT03463642), changes in serum 25(OH)D over a 4-week period using a capillary spot method were monitored. 62 female participants blindly chose a number related to a supplementation delivery method: pill placebo, pill, oral liquid, oral liquid placebo, Skin oil application (SOA) placebo, SOA plus vitamin D₃ suspension, or SOA plus vitamin D₃ suspension with essential oil enhancer; active vitamin D supplements contained 100,000IU. Participants took their allocated supplements over a 24-hr period with serum 25(OH)D retested 4 weeks later. Liquid chromatography-tandem mass spectrometry method was applied to dried blood spot samples by an independent laboratory.

RESULTS

ANCOVA reported a significant difference between the groups (F_1,6 = 146.68; p < 0.001, eta² = 0.51). Separate analysis within the delivery methods (pill, SOA, oral liquid) indicated significant differences between the active and placebo supplementation groups (p < 0.01). Post hoc analysis of absolute changes indicated vit D pill and SOA + vit D + essential oil had significant increases (p < 0.05) in serum 25(OH)D compared to all other interventions with no significant difference between them.

CONCLUSIONS

In human participants vitamin D oral pill has the greatest effect on serum 25(OH)D levels. Skin oil application delivery of vitamin D using a penetrator enhancer has also been shown to be an effective method of delivery.