Pediatric sepsis responds to Vitamin D — faster forms likely work better

Question: Can Sepsis in children be treated by fast-acting Vitamin D?

Claude AI - April 2026

Short answer: yes, with caveats — the evidence supports rapid vitamin D repletion as adjunctive therapy in pediatric sepsis, particularly in deficient children, but it's not a replacement for antibiotics and supportive care.

RCT trial with 150,000 IU: reduced Septic Shock from 20% to 7%

Wang et al. 2020 (PICU, China, n=109) — the most directly relevant pediatric RCT. Children with vitamin D deficiency and sepsis received a single 150,000 IU oral cholecalciferol bolus or placebo. Ang-II, IL-6, and TNF-α concentrations were all reduced after vitamin D supplementation. The cv-SOFA score (1.76 ± 0.8 vs. 2.3 ± 1.1) and incidence of septic shock (7% vs. 20%) were lower in the treatment group than in the control group. The duration of ventilation and mortality rates did not differ between two groups. A 13-percentage-point absolute reduction in progression to septic shock is clinically meaningful even if mortality wasn't powered.

(Wang "Effects of a single dose of vitamin D in septic children: a randomized, double-blinded, controlled trial." Journal of International Medical Research 48(5): 0300060520926890 DOI: 10.1177/0300060520926890)

Neonatal sepsis trials are more modest in dosing — typically 400 vs 800 IU/day cholecalciferol — and show CRP/IL-6 improvements but with the obvious limitation that those doses don't rapidly raise 25(OH)D.

VITdAL-PICU (Children's Hospital of Eastern Ontario, NCT02452762) established that high loading doses can safely and rapidly normalize 25(OH)D in critically ill children, providing the dosing groundwork for the larger VITdALIZE-KIDS Phase III trial that is now testing whether rapid repletion improves PICU outcomes.

Why "fast-acting" matters here

Cholecalciferol bolus dosing works but takes days for the liver to 25-hydroxylate it. Sepsis kills on a timescale of hours. Two routes get around this:

Calcifediol (25-OH-D3) — bypasses hepatic hydroxylation. Oral calcifediol increases the serum 25(OH)D levels more rapidly and is about 3.2-fold more potent than cholecalciferol. The Castillo Córdoba COVID-19 trial in adults showed dramatic ICU-admission reductions, and adult sepsis data (Quraishi et al. with 200,000–400,000 IU cholecalciferol) showed High-dose cholecalciferol supplementation rapidly and safely improves 25-hydroxyvitamin D and bioavailable 25-hydroxyvitamin D levels in patients with severe sepsis or septic shock. Changes in bioavailable 25-hydroxyvitamin D are associated with concomitant increases in circulating LL-37 levels. That cathelicidin signal is the mechanistic link to bacterial killing.
Liposomal/nanoemulsion D3 — your area of recent research. The PK case for these in deficient populations is the same case as for calcifediol: get circulating 25(OH)D into the immunologically useful range (>50 ng/mL) within hours rather than days. No published pediatric sepsis RCT yet uses these forms specifically — that's a real gap in the literature.

Mechanism (why it works at all)

The cathelicidin/LL-37 pathway requires adequate intracellular 25(OH)D for macrophages to mount their antimicrobial response. Septic patients are typically deficient on admission, and their VDBP levels drop, further reducing bioavailable 25(OH)D. Fixing the substrate problem fast lets the innate immune machinery actually work — which is why Leaf et al. saw cathelicidin mRNA changes within 24 hours after IV calcitriol in adult sepsis.

* The honest caveats*

Pediatric trial sample sizes are small (~100 each). The shock-incidence signal is real but needs replication.
Mortality benefit has not been demonstrated in children — only in the severe-deficiency subgroup of adult VITdAL-ICU.
Calcifediol is not widely available pediatrically in the US; off-label adult formulations don't have pediatric dose-finding data.
This is adjunctive. Nothing replaces source control, antibiotics, and resuscitation.

Neonate sepsis 2.3 X more likely if <30 ng of vitamin D - May 2026

_A systematic review and meta-analysis of Vitamin D status and clinical outcomes in critically ill neonates _

Front. Nutr., Sec. Clinical Nutrition

PDF should be available later in 2027

Chai-Hoon Nowel Tan 1. Charmaine Shi Mei Lee , Eirena Beh 1, Darolyn Jia Lin Tan 1, Ruther Teo Zheng 1, Daniel Chan 1,3 - Singapore

Introduction Vitamin D is key in immunoregulation and impacts critical care outcomes. With a high prevalence of neonatal Vitamin D deficiency (VDD), we aim to evaluate its association with clinical outcomes in the neonatal intensive care unit (NICU).

Methods Systematic search of PubMed, EMBASE, Web of Science and Scopus was conducted. Primary outcomes included mortality and incidence of sepsis, while secondary outcomes were length of stay (LOS), incidence of bronchopulmonary dysplasia (BPD), and need for mechanical ventilation (MV). Eligible studies included preterm and term NICU neonates with 25-hydroxyvitamin D levels reported on admission. Definition of VDD was based on individual studies due to significant inter-study heterogeneity, however further sub-analyses with VDD definitions of ≤ 30ng/mL and Vitamin D sufficient (VDS) >30ng/mL were performed to evaluate possible dose-response relationships. Pooled estimates were calculated with random-effects model due to study heterogeneity.

Results Among 2735 articles, 18 studies met predefined inclusion criteria (n = 1981 patients). VDD was associated with

*increased incidence of sepsis (odds ratio [OR] 2.31, 95%CI 1.50-3.57), *length of hospital stay (mean difference 4.52 days, 95% CI 1.66-7.37) and *need for MV (OR 1.67, 95%CI 1.09-2.55), in comparison to VDS neonates.

Further subgroup analyses for * preterm (OR 2.05, 95%CI 1.04-4.04) and *term neonates (OR 3.96, 95%CI 1.68-9.35)

continued to show significant association between VDD and sepsis. No differences were observed between both groups for mortality and incidence of BPD. Further subgroup analyses based on Vitamin D levels found that those ≤ 30ng/ml had no significant difference (mean difference 0 days, 95%CI -1.89 - 1.89) in terms of length of hospital stay.

Conclusion VDD in critically ill neonates is significantly associated with increased odds of sepsis, need for MV, and longer LOS. However, these findings are limited by significant heterogeneity across studies. This warrants further interventional studies, involving both term and preterm neonates, to examine the potential of optimization of Vitamin D levels to improve critical care outcomes in NICU.