Trial reportMedicine and science in sports and exercise2021
Influence of Vitamin D Supplementation by Simulated Sunlight or Oral D3 on Respiratory Infection during Military Training.
Trial report in Medicine and science in sports and exercise, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
13 citing papers in PubMed, 1 synthesis or guideline pooled it, 24 citations in OpenAlex.
- Select Dietary Supplement Ingredients for Preserving and Protecting the Immune System in Healthy Individuals: A Systematic Review.Nutrients · 2022Pooled it
- Effects of Vitamin D Supplementation and Baseline Vitamin D Status on Acute Respiratory Infections and Cathelicidin: A Randomized Controlled Trial.Open forum infectious diseases · 2024Trial
- Infection as an Exertional Heat Illness Risk Factor: A Prospective Cohort Study.Medicine and science in sports and exercise · 2026Article
- A Comparison of Training, Injury, Illness, Sleep, Wellbeing and Stress Between Developing Elite and Recreational Athletes.European journal of sport science · 2025Article
- Comparative effectiveness of oral nutritional supplements in preventing respiratory tract infections among adults: a systematic review and network meta-analysis.EClinicalMedicine · 2025Article
- Inflammation in cancer: therapeutic opportunities from new insights.Molecular cancer · 2025Review
- High dose vitamin D supplementation decreases the risk of deficiency in male conscripts, but has no effect on physical performance-A randomized study.Journal of experimental orthopaedics · 2024Article
- Sex differences in iron status during military training: a prospective cohort study of longitudinal changes and associations with endurance performance and musculoskeletal outcomes.The British journal of nutrition · 2024Article
- Nutrition, Immune Function, and Infectious Disease in Military Personnel: A Narrative Review.Nutrients · 2023Review
- Vitamin D status modulates innate immune responses and metabolomic profiles following acute prolonged cycling.European journal of nutrition · 2023Article
- Distinguishing science from pseudoscience in commercial respiratory interventions: an evidence-based guide for health and exercise professionals.European journal of applied physiology · 2023Review
- Article
- 25-Hydroxyvitamin D potentializes extracellular cathelicidin release from human PBMC stimulated ex vivo with either bacterial (LPS) or viral (P: IC) mimetics.Journal of physiology and biochemistry · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
15 authors at 8 institutions in 2 countries.
Funding
Abstract
purposeThis study aimed to determine the relationship between vitamin D status and upper respiratory tract infection (URTI) of physically active men and women across seasons (study 1) and then to investigate the effects on URTI and mucosal immunity of achieving vitamin D sufficiency (25(OH)D ≥50 nmol·L-1) by a unique comparison of safe, simulated sunlight or oral D3 supplementation in winter (study 2).
methodsIn study 1, 1644 military recruits were observed across basic military training. In study 2, a randomized controlled trial, 250 men undertaking military training received placebo, simulated sunlight (1.3× standard erythemal dose, three times per week for 4 wk and then once per week for 8 wk), or oral vitamin D3 (1000 IU·d-1 for 4 wk and then 400 IU·d-1 for 8 wk). URTI was diagnosed by a physician (study 1) and by using the Jackson common cold questionnaire (study 2). Serum 25(OH)D, salivary secretory immunoglobulin A (SIgA), and cathelicidin were assessed by liquid chromatography-mass spectrometry LC-MS/MS and enzyme-linked immunosorbent assay.
resultsIn study 1, only 21% of recruits were vitamin D sufficient during winter. Vitamin D-sufficient recruits were 40% less likely to suffer URTI than recruits with 25(OH)D <50 nmol·L-1 (OR = 0.6, 95% confidence interval = 0.4-0.9), an association that remained after accounting for sex and smoking. Each URTI caused, on average, three missed training days. In study 2, vitamin D supplementation strategies were similarly effective to achieve vitamin D sufficiency in almost all (≥95%). Compared with placebo, vitamin D supplementation reduced the severity of peak URTI symptoms by 15% and days with URTI by 36% (P < 0.05). These reductions were similar with both vitamin D strategies (P > 0.05). Supplementation did not affect salivary secretory immunoglobulin A or cathelicidin.
conclusionVitamin D sufficiency reduced the URTI burden during military training.
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Registered trials
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