Vitamin D may prevent asthma worsening for some

Conclusion This review gathers the available trial evidence to address the specific question of whether giving people with asthma vitamin D supplements could have an effect on how many asthma exacerbations they have. The review has many strengths. It only included double-blind trials, where participants and assessors didn't know if people were taking vitamin D or a placebo. Researchers also made careful attempts to gather all relevant data and information on confounding factors, and all but one trial had a low risk of bias. But there are some limitations to bear in mind: With the relatively small number of trials and participants, the outcome of interest – exacerbations needing steroid treatment – was quite rare. Three trials recorded no exacerbations, and a third only one. Analyses based on a small number of events can give less precise risk estimates. The main aim was to see whether a person's vitamin D levels to begin with had an effect. The researchers found there was: the benefit was only seen in people who were vitamin D deficient to start with. But only 92 people fell into this category, so again the small number of events in this sample may give a less reliable result. The dosing and duration of treatment varied from study to study. Along with the small sample and low number of events, this makes it difficult to know what could be an optimal dose for children or adults to take. This study, and the research it's based on, isn't able to tell us whether ther...
Source: NHS News Feed - Category: Consumer Health News Tags: Heart/lungs Source Type: news