One of the biggest
observational studies looking at multivitamins and health involved over 160,000 postmenopausal women aged 50 to 79 years . Over 40 percent of women were taking a multivitamin supplement , yet over the eight years of the study , there was no link between taking these supplements and the risk of developing cancer , cardiovascular disease , or dying earlier .
For heart disease , the
most recent systematic review and meta-analysis of 18 observational studies involving over two million participants found no association between multivitamin supplementation and cardiovascular disease outcomes or lifespan .
Randomised-controlled trials are superior for investigating any direct effects of multivitamins on health outcomes . But , way back in 2006 , a
comprehensive review looking at only randomised-controlled clinical trials found that the use of multivitamins did not reduce the risk of any chronic disease .
In more recent research , a 2015
critical review also found that the majority of scientific studies reported no significant effect of multivitamins on chronic disease . The review did note some benefit of multivitamins in reducing the risk of developing cancer in men , yet no strong evidence shows that women may also benefit .
There is
some evidence that multivitamins that include high doses of antioxidants may help to reduce the risk of cataracts and age-related macular degeneration , but we are still waiting on higher-quality studies to confirm this .
Multivitamins can help with deficiencies
It is not all negative news for multivitamins though . Taking a multivitamin supplement helps people obtain the recommended intakes of vitamins and minerals when they cannot meet these needs from food alone . There are many situations where this is the case such as :
} people more likely to have a poor food intake such as those on restricted diets or the elderly
} women planning pregnancy where taking folic acid and other nutrients such as iodine , iron and vitamin D before and during pregnancy is well-supported by scientific evidence
} people following a vegan diet where vitamin B12 deficiency can be an issue } people who are chronic drinkers of alcohol .
Food is more than vitamins and minerals
All this discussion on multivitamin supplements can obscure the forest for the trees . Humans eat food and food is a complex source of vitamins , minerals and phytochemicals
A COMPREHENSIVE REVIEW LOOKING AT ONLY RANDOMISED-CONTROLLED CLINICAL TRIALS FOUND THAT THE USE OF MULTIVITAMINS DID NOT REDUCE THE RISK OF ANY CHRONIC DISEASE .
( plant chemicals ), which all work together to keep us healthy . Supplements tend to work in isolation and only contain a fraction of the nutrients that can be found in a diverse diet .
A key example of this are polyphenols , which are linked to a host of protective health benefits ( against cancer , diabetes and inflammation ). There are over 8,000 different types of polyphenols found in coffee , fruits , grains , legumes , tea and vegetables . Yet it ’ s rare to find any of these added to a broad-spectrum multivitamin .
What to look for in a supplement
If you do decide to take a multivitamin supplement , then what should you look for ? Firstly , it should deliver close to the
recommended daily intake for most of the vitamins and minerals .
Choose a multivitamin tailored to your age , gender , and other characteristics such as if you are pregnant . Multivitamins for women usually contain more iron for example , whereas those for seniors typically provide more calcium and vitamins D and B12 .
Summary
Multivitamins have their use for people with vitamin and mineral deficiencies , but they don ’ t appear to offer many health benefits for the general population . If you feel that you could be lacking in certain vitamins and minerals , it may be better to look at changing your diet and lifestyle rather than reaching for supplements . If you need help , see your doctor or a dietitian .
YMCA HEALTHY LIVING MAGAZINE 9