Multivitamins don't prevent infections in all elderly, suggests study

Previous research has shown that when taking vitamin E supplements, elderly people in nursing homes were 20 per cent less likely to get a cold and also had less colds over the study period than a placebo group.

Other trials have found other supplements, especially of trace elements, have reduced infections in older people in care.

But for those living at home, where risk of infection is lower than in residential care, multivitamin supplements may not offer the same benefit, suggests the new research published in this week's British Medical Journal​ (vol 331, pp 324-7).

The researchers at Aberdeen University recruited 910 men and women aged 65 or over who did not take vitamins or minerals and randomised them to receive either a daily multivitamin and multimineral supplement or a placebo for one year.

During this time, participants were asked to record contacts with primary care for infection, number of days with infection and quality of life. Numbers of antibiotic prescriptions and hospital admissions were also taken into account.

At least 10 per cent of older people are thought to have a vitamin or mineral deficiency, which can lead to poor immunity and increased risk of infection. Some vitamins and minerals are known to boost the immune system.

But taking the multivitamin and mineral supplement did not affect incidence of infection or overall quality of life in the Scottish subjects.

"Regular use of commonly available multivitamin and multimineral supplements is unlikely to reduce the number of self-reported infections or associated use of health services for people living at home,"​ write the authors.

Their findings are consistent with several other studies in this area, including a meta-analysis of eight different trials published in the BMJ in April that found no benefit of multivitamins on infections in the elderly.

But the Scottish authors note: "We cannot exclude the possibility that the intakes provided in the supplement were inadequate to affect the immune system."​

This area of research is increasingly important as the elderly population grows in numerous countries around the world. People over the age of 65 are set to make up a quarter of the total European population by 2020. This population segment is more prone to infection than others.

At least a quarter of older people in the UK already take nutritional supplements but while they may have other health benefits, it is not yet clear whether this practice can reduce common infections.

The authors add that it remains to be seen whether older people living in care would benefit from supplementation.