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Got It, Hide thisMartineau AR, Jolliffe DA, Hooper RL, et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. 2017 Feb 15;356:i6583.
In children and adults, do vitamin D supplements reduce risk for acute respiratory tract infections (ARTIs)?
ARTIs include the common cold, bronchitis, and pneumonia. Some studies have found that people with low vitamin D levels have an increased risk for ARTIs. People may have low vitamin D levels when they don’t have regular exposure to sunlight or don’t get enough vitamin D in the foods they eat. This review looks at whether vitamin D supplements can reduce your risk for getting an ARTI.
The researchers did a systematic review of studies available up to December 2015. They found 25 randomized controlled trials (RCTs) with 11,321 people (about 50% girls or women). Most people were younger than 16 years of age, 28% were between 16 and 65 years of age, and 11% (about 1,200 people) were older than 65 years of age.
The key features of the RCTs were:
The evidence for the effect of vitamin D3 supplements on ARTIs was of high quality (high confidence in results).
Compared with placebo, vitamin D3 supplements:
In children and adults, vitamin D3 supplements reduce acute respiratory tract infections.
Note: Vitamin D3 supplements are not safe for everyone. Ask your doctor if taking vitamin D3 supplements is a good idea for you.
Outcomes | Number of trials and people | Rate of events with vitamin D3 supplements* | Rate of events with placebo | Absolute effect of vitamin D3 supplements |
Any ARTI | 25 trials (10,933 people) | 39% | 42% | About 3 fewer people out of 100 had an ARTI (from as few as 1 person to as many as 5 people)† |
ARTI-related hospitalization or emergency department visit | 11 trials (7,872 people) | 1.0% | 1.2% | No difference in effect‡ |
Death | 25 trials (11,224 people) | 1.2% | 0.9% | No difference in effect‡ |
Serious adverse events | 25 trials (11,224 people) | 3.9% | 4.0% | No difference in effect‡ |