The BMJ Today: Vitamin D, probiotics, and polio

We have been longing for a final word on whether vitamin D supplements improve health. An umbrella review published today included 107 systematic literature reviews and 74 meta-analyses of observational studies looking at serum levels of vitamin D, as well as 87 meta-analyses of randomised trials testing vitamin D supplements. A total of 137 outcomes were included, spanning a wide array of diseases.

We’ve also published a systematic review and meta-analysis of 73 cohort studies with over 800 000 participants and 22 randomised trials with 30 000 participants that examined the link between vitamin D and deaths due to cardiovascular disease, cancer, and other causes.

In a research news piece summarising the studies, Zosia Kmietowicz writes, “multiple claims for the benefits of vitamin D supplementation are unfounded.” The editorialists suggest doctors should avoid measuring 25-hydroxyvitamin D in asymptomatic patients without bone disease. Supplementation with vitamin D may seem like a cheap, better than nothing attempt at helping people improve health, but it may also harm, by increasing the risk of hypercalcaemia, and providing false reassurance of a prescription prevention pill, making it easier for people to lead poorer lifestyles. Still, for hope of a final word on vitamin D, we now turn to bigger and better trials that are under way, like VITAL, the results of which are due in 2017.

Elsewhere Sung et al report on a randomised placebo controlled trial that shows that probiotics don’t seem to help colicky babies, breast and bottle fed alike.

And, as India celebrates being free of new cases of polio for three years, it can turn its attention to survivors of the disease. Some of these people may have post-polio syndrome, which usually occurs 15 to 40 years after acute poliomyelitis and includes muscle weakness, fatigue, joint and muscle pain, intolerance to cold, and difficulties sleeping, breathing, or swallowing. Loss of muscle function and pain can be helped by “simple things like changing callipers, reducing daily activities, gentle exercises, and resting where possible.” A number of programmes are under way to help survivors of polio, including disability pensions for those with multiple or severe disabilities, who get 200 rupees a month from the central government, and possibly the same amount or up to 1000 rupees a month from state governments.

Kristina Fister is an associate editor, BMJ.