Explore the vast range of titles available.

Vitamin D 3 is an essential micronutrient that supports innate immunity and modulates adaptive responses, with in vitro studies implicating epigenetic mechanisms. Yet, in vivo evidence for such regulation remains scarce. Here, we assessed genome-wide epigenomic and transcriptomic responses to vitamin D 3 in a high responder from the VitDHiD repeated-measures, non-randomized interventional N-of-1 study, in which the participant received monthly oral boluses of 80,000 IU vitamin D 3 over three months. Peripheral blood mononuclear cells (PBMCs) were collected at baseline (day 0) and at 24 and 48 h post-supplementation (days 1 and 2) for ATAC-seq and RNA-seq profiling. ATAC-seq identified > 3,500 regions with increased chromatin accessibility, predominantly at promoters, indicating a strong epigenomic activation. Motif enrichment revealed immune-regulatory transcription factors, but not vitamin D receptor (VDR) motifs, suggesting indirect or cooperative modes of regulation. RNA-seq detected 380 vitamin D–responsive genes with time-dependent expression changes, including DUSP6 and FOS , enriched in pathways related to innate immunity and interferon signaling. Integrative analysis linked 306 differentially expressed genes to vitamin D–sensitive chromatin regions. Many of these overlap with VDR binding sites or promoters of neighboring non-target genes, suggesting potential long-range regulation. Shared enhancers and promoters among neighboring genes indicated redundancy in regulatory architecture. Analysis of PBMCs from 13 participants in the VitDPAS non-randomized interventional cohort study, each receiving a single vitamin D 3 bolus, confirmed the main findings from the N-of-1 study but also revealed pronounced inter-individual variability in epigenomic and transcriptomic responses. Together, these results provide in vivo evidence that vitamin D signaling directly and indirectly modulates chromatin accessibility and gene expression, emphasizing its role as an epigenetic regulator of immune function and supporting its potential in personalized nutrition and immune health strategies.

The VitDPAS study (NCT06104111) was designed as a medical experiment to assess the in vivo effects of vitamin D on immune responses. This study enrolled 45 healthy individuals from Olsztyn, Poland, who received a body weight-adjusted bolus dose of vitamin D 3 (1,000 IU/kg). Transcriptome-wide differential gene expression analysis of peripheral blood mononuclear cells, collected before and 24 h after supplementation, identified 758 significantly responsive genes ( p  < 0.05). By correlating individual gene expression changes with alterations in vitamin D status, participants were categorized into three response groups: 17 high responders, 19 mid responders, and 9 low responders. A comparative analysis with the VitDHiD study (NCT03537027), conducted on a Finnish cohort of 25 healthy participants, revealed 232 overlapping target genes, enabling an integrated assessment of vitamin D responsiveness across all 70 individuals. Applying a more stringent statistical threshold (false discovery rate < 0.05) highlighted 26 shared target genes, demonstrating a consistent in vivo response to vitamin D 3 across both cohorts. The modulation of inflammatory processes, mediated primarily via tumor necrosis factor and nuclear factor κB signaling pathways, emerged as a shared effect, highlightening the immunomodulatory potential of vitamin D as a key function of the vitamin in healthy individuals.

Vitamin D intervention studies are designed to evaluate the impact of the micronutrient vitamin D[sub.3] on health and disease. The appropriate design of studies is essential for their quality, successful execution, and interpretation. Randomized controlled trials (RCTs) are considered the “gold standard” for intervention studies. However, the most recent large-scale (up to 25,000 participants), long-term RCTs involving vitamin D[sub.3] did not provide any statistically significant primary results. This may be because they are designed similarly to RCTs of a therapeutic drug but not of a nutritional compound and that only a limited set of parameters per individual were determined. We propose an alternative concept using the segregation of study participants into different groups of responsiveness to vitamin D[sub.3] supplementation and in parallel measuring a larger set of genome-wide parameters over multiple time points. This is in accordance with recently developed mechanistic modeling approaches that do not require a large number of study participants, as in the case of statistical modeling of the results of a RCT. Our experience is based on the vitamin D intervention trials VitDmet, VitDbol, and VitDHiD, which allowed us to distinguish the study participants into high, mid, and low vitamin D responders. In particular, investigating the vulnerable group of low vitamin D responders will provide future studies with more conclusive results both on the clinical and molecular benefits of vitamin D[sub.3] supplementation. In conclusion, our approach suggests a paradigm shift towards detailed investigations of transcriptome and epigenome-wide parameters of a limited set of individuals, who, due to a longitudinal design, can act as their own controls.

Vitamin D intervention studies are designed to evaluate the impact of the micronutrient vitamin D3 on health and disease. The appropriate design of studies is essential for their quality, successful execution, and interpretation. Randomized controlled trials (RCTs) are considered the “gold standard” for intervention studies. However, the most recent large-scale (up to 25,000 participants), long-term RCTs involving vitamin D3 did not provide any statistically significant primary results. This may be because they are designed similarly to RCTs of a therapeutic drug but not of a nutritional compound and that only a limited set of parameters per individual were determined. We propose an alternative concept using the segregation of study participants into different groups of responsiveness to vitamin D3 supplementation and in parallel measuring a larger set of genome-wide parameters over multiple time points. This is in accordance with recently developed mechanistic modeling approaches that do not require a large number of study participants, as in the case of statistical modeling of the results of a RCT. Our experience is based on the vitamin D intervention trials VitDmet, VitDbol, and VitDHiD, which allowed us to distinguish the study participants into high, mid, and low vitamin D responders. In particular, investigating the vulnerable group of low vitamin D responders will provide future studies with more conclusive results both on the clinical and molecular benefits of vitamin D3 supplementation. In conclusion, our approach suggests a paradigm shift towards detailed investigations of transcriptome and epigenome-wide parameters of a limited set of individuals, who, due to a longitudinal design, can act as their own controls.

Vitamin D intervention studies are designed to evaluate the impact of the micronutrient vitamin D on health and disease. The appropriate design of studies is essential for their quality, successful execution, and interpretation. Randomized controlled trials (RCTs) are considered the \"gold standard\" for intervention studies. However, the most recent large-scale (up to 25,000 participants), long-term RCTs involving vitamin D did not provide any statistically significant primary results. This may be because they are designed similarly to RCTs of a therapeutic drug but not of a nutritional compound and that only a limited set of parameters per individual were determined. We propose an alternative concept using the segregation of study participants into different groups of responsiveness to vitamin D supplementation and in parallel measuring a larger set of genome-wide parameters over multiple time points. This is in accordance with recently developed mechanistic modeling approaches that do not require a large number of study participants, as in the case of statistical modeling of the results of a RCT. Our experience is based on the vitamin D intervention trials VitDmet, VitDbol, and VitDHiD, which allowed us to distinguish the study participants into high, mid, and low vitamin D responders. In particular, investigating the vulnerable group of low vitamin D responders will provide future studies with more conclusive results both on the clinical and molecular benefits of vitamin D supplementation. In conclusion, our approach suggests a paradigm shift towards detailed investigations of transcriptome and epigenome-wide parameters of a limited set of individuals, who, due to a longitudinal design, can act as their own controls.

Vitamin D is an essential micronutrient that supports innate immunity and modulates adaptive responses, with in vitro studies implicating epigenetic mechanisms. Yet, in vivo evidence for such regulation remains scarce. Here, we assessed genome-wide epigenomic and transcriptomic responses to vitamin D in a high responder from the VitDHiD repeated-measures, non-randomized interventional N-of-1 study, in which the participant received monthly oral boluses of 80,000 IU vitamin D over three months. Peripheral blood mononuclear cells (PBMCs) were collected at baseline (day 0) and at 24 and 48 h post-supplementation (days 1 and 2) for ATAC-seq and RNA-seq profiling. ATAC-seq identified > 3,500 regions with increased chromatin accessibility, predominantly at promoters, indicating a strong epigenomic activation. Motif enrichment revealed immune-regulatory transcription factors, but not vitamin D receptor (VDR) motifs, suggesting indirect or cooperative modes of regulation. RNA-seq detected 380 vitamin D-responsive genes with time-dependent expression changes, including DUSP6 and FOS, enriched in pathways related to innate immunity and interferon signaling. Integrative analysis linked 306 differentially expressed genes to vitamin D-sensitive chromatin regions. Many of these overlap with VDR binding sites or promoters of neighboring non-target genes, suggesting potential long-range regulation. Shared enhancers and promoters among neighboring genes indicated redundancy in regulatory architecture. Analysis of PBMCs from 13 participants in the VitDPAS non-randomized interventional cohort study, each receiving a single vitamin D bolus, confirmed the main findings from the N-of-1 study but also revealed pronounced inter-individual variability in epigenomic and transcriptomic responses. Together, these results provide in vivo evidence that vitamin D signaling directly and indirectly modulates chromatin accessibility and gene expression, emphasizing its role as an epigenetic regulator of immune function and supporting its potential in personalized nutrition and immune health strategies.

The VitDPAS study (NCT06104111) was designed as a medical experiment to assess the in vivo effects of vitamin D on immune responses. This study enrolled 45 healthy individuals from Olsztyn, Poland, who received a body weight-adjusted bolus dose of vitamin D (1,000 IU/kg). Transcriptome-wide differential gene expression analysis of peripheral blood mononuclear cells, collected before and 24 h after supplementation, identified 758 significantly responsive genes (p < 0.05). By correlating individual gene expression changes with alterations in vitamin D status, participants were categorized into three response groups: 17 high responders, 19 mid responders, and 9 low responders. A comparative analysis with the VitDHiD study (NCT03537027), conducted on a Finnish cohort of 25 healthy participants, revealed 232 overlapping target genes, enabling an integrated assessment of vitamin D responsiveness across all 70 individuals. Applying a more stringent statistical threshold (false discovery rate < 0.05) highlighted 26 shared target genes, demonstrating a consistent in vivo response to vitamin D across both cohorts. The modulation of inflammatory processes, mediated primarily via tumor necrosis factor and nuclear factor κB signaling pathways, emerged as a shared effect, highlightening the immunomodulatory potential of vitamin D as a key function of the vitamin in healthy individuals.