Skip to main content
Evidence-Based Supplement Research
Evidence-Based Supplement Research
Pillser
Search
Sign UpLog In

A 12-week double-blind randomised controlled trial investigating the effect of dietary supplementation with 125 μg/d vitamin D in adults with asthma.

  • 2024-05-16
  • The British journal of nutrition 132(6)
    • Stephanie Watkins
    • Tanja Harrison
    • Sohail Mushtaq

Study Design

Type
Randomized Controlled Trial (RCT)
Sample size
n = 32
Population
32 adults with mild to moderate asthma
Methods
12-week placebo-controlled randomised controlled trial administering a daily 125 µg vitamin D3 supplement
Blinding
Double-blind
Duration
12 weeks
Vitamin D deficiency has previously been linked to higher rates of exacerbation and reduced lung function in asthmatics. Previous randomised controlled trials investigating the effect of vitamin D supplementation have mainly focused on children with asthma. Trials involving adults have typically used bolus dosing regimens, and the main outcomes have been patient-focused without investigating underlying inflammation. The present study aimed to conduct a 12-week placebo-controlled randomised controlled trials administering a daily 125 µg vitamin D3 supplement to adults with mild to moderate asthma. A total of 32 participants were randomised to receive either the 125 μg vitamin D3 supplement or an identical matching placebo. The primary outcome of the study was lung function measured by the ratio of FEV1:FVC (effect size 2·5) with secondary outcomes including asthma symptoms and inflammatory biomarkers. There was a small but statistically significant higher increase in the mean (±sd) ratio of FEV1:FVC from baseline to post-intervention in the vitamin D group (+0·05 ± 0·06) compared with the placebo group (+0·006 ± 0·04, P = 0·04). There was no effect of the intervention on asthma control test scores, or the inflammatory biomarkers measured. There was a moderate, significant association between baseline plasma 25(OH)D concentration and baseline plasma IL-10 (r = 0·527, P = 0·005) and TNF-α (r = −0·498. P = 0·008) concentrations. A daily vitamin D3 supplement led to slightly improved lung function in adult asthmatics and may be a useful adjunct to existing asthma control strategies, particularly for individuals with suboptimal vitamin D status.

Research Insights

  • Vitamin D→Improved Asthma Control Test Score

    There was no effect of the intervention on asthma control test scores

    Effect
    Neutral
    Effect size
    Small
    Dose
    125 μg/d
  • Vitamin D→Improved Lung Function

    There was a small but statistically significant higher increase in the mean (±sd) ratio of FEV1:FVC from baseline to post-intervention in the vitamin D group (+0·05 ± 0·06) compared with the placebo group (+0·006 ± 0·04, P = 0·04).

    Effect
    Beneficial
    Effect size
    Small
    Dose
    125 μg/d
  • Vitamin D→Reduced Inflammatory Markers

    There was no effect of the intervention on asthma control test scores, or the inflammatory biomarkers measured.

    Effect
    Neutral
    Effect size
    Small
    Dose
    125 μg/d
Back to top