In our regular column on research that's relevant to physiotherapists, Janet Wright looks at the latest clinical findings.
Confused about vitamin D?
During the past few years deficiency in this ‘sunshine vitamin’ has been linked with numerous health problems including heart disease, cancers and infections. Yet many questions remain about the nature of the link and about the role of supplements.
Our bodies make vitamin D naturally from the effect of sunshine on our skin, and use it to build strong bones. But fear of skin cancer has made people cover up more in recent years, and those of us living far from the Equator may not get enough during the winter anyway.
Researchers are still discovering its benefits. Children whose mothers had higher levels of vitamin D during pregnancy have a stronger grip at the age of four, according to a study from the Southampton Women’s Survey.
The authors are still investigating whether supplementation is required. Supplements can be prescribed to people who have, or are at risk of, a specific condition. But they are not for everyone.
Recent reports suggest that supplements are not required for general health or even to keep bones strong.
Mark Bolland and colleagues did a meta-analysis of published studies into vitamin D supplements’ effects on cardiovascular disease, cancers and fractures. They found little clear evidence of benefit, except that vitamin D plus calcium reduced hip fractures among elderly women in care homes.
‘In view of our findings, there is little justification for prescribing vitamin D supplements to prevent myocardial infarction or ischaemic heart disease, stroke or cerebrovascular disease, cancer, or fractures, or to reduce the risk of death in unselected community-dwelling individuals,’ the authors report.
Some research suggests that rather than causing disease, vitamin D deficiency might actually be caused by the inflammatory processes involved in diseases.
This ‘would explain why low vitamin D status is reported in a wide range of disorders,’ say Philippe Autier and colleagues. ‘In elderly people, restoration of vitamin D deficits due to ageing and lifestyle changes induced by ill health could explain why low-dose supplementation leads to slight gains in survival.’
Supplementation could even be risky. Commenting in the Lancet, orthopaedic specialist Karl Michaëlsson concludes that ‘vitamin D supplementation might actually cause net harm’ when taken by people who don’t need it.
Harvey NC et al.
Maternal antenatal vitamin D status and offspring muscle development: findings from the Southampton Women’s Survey.
Journal of Clinical Endocrinology & Metabolism 2014; http://dx.doi.org/10.1210/jc.2013-3241 Bolland MJ et al.
The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis.
Lancet Diabetes & Endocrinology 2014; http://dx.doi.org/10.1016/S2213-8587(13)70212-2 Michaëlsson K. The puzzling world of vitamin D insufficiency.
Lancet Diabetes & Endocrinology 2014; http://dx.doi.org/10.1016/S2213-8587(14)70008-7 Autier P et al.
Vitamin D status and ill health: a systematic review.
Lancet Diabetes & Endocrinology 2014; http://dx.doi.org/10.1016/S2213-8587(13)70165-7
Dementia - Exercise can help older people with dementia
Exercise can ease some of the symptoms of dementia, according to a Cochrane review of 16 randomised controlled trials with a total of 937 participants.
‘There was promising evidence that exercise programmes can significantly improve the cognitive functioning of people with dementia and their ability to perform daily activities,’ say Dorothy Forbes and colleagues.
Exercise might even delay the need for a patient to go into a care home.
Dorothy Forbes and colleagues were looking at the impact of dementia on healthcare services and on family members who were carers, as well as on the patients themselves.
One study showed that the pressure on family carers might be reduced if they supervised their relative in an exercise programme.
‘Healthcare providers who work with people with dementia and their caregivers should feel confident in promoting exercise among this population, as decreasing the progression of cognitive decline and dependence … will have significant benefits for people with dementia and their family caregivers’ quality of life,’ the authors conclude.
They warn, however, that there was a lot of variation among results of the trials.
Forbes D et al.
Exercise programmes for people with dementia. Cochrane Database of Systematic Reviews 2013;
Comments & Conclusions
- Giving brief advice in primary care is a cost-effective means of increasing adults’ physical activity, researchers report. Anokye NK et al. British Journal of Sports Medicine 2014, http://dx.doi.org/10.1136/bjsports-2013-092897 This appears in a special issue devoted to exercise, February 2014, volume 2, issue 3:http://bjsm.bmj.com/content/48/3.toc
- Middle-aged men who were fit in their teens are less likely than others to have a heart attack, a study of nearly 750,000 men has found. But fit teenagers who were overweight had a higher risk, despite their fitness, than those who were thin even ifunfit. Högström G et al. European Heart Journal 2014; http://dx.doi.org/10.1093/eurheartj/eht527
- Some 85 per cent of patients diagnosed with chronic obstructive pulmonary disease could have had an earlier diagnosis if their symptoms hadn’t been missed during an earlier visit to a doctor or clinic. Jones RCM et al. Lancet 2014; http://dx.doi.org/10.1016/S2213-2600(14)70008-6
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