The scientific body of evidence would suggest there is little benefit to be gained by taking a multivitamin supplement if you are in good general health.
The Department of Health says that if you eat a healthy balanced diet, you don't need to take supplements, unless you have been advised to do so by your doctor.
The exception is that women of childbearing age who are sexually active are advised to take a 400ug folic-acid supplement every day, regardless of how healthy their diet is.
Many don’t, despite the evidence that doing so can prevent neural-tube defects in their babies.
A prospective Irish observational study examined maternal supplement use and found that only 200 out of the 450 mothers complied with the recommendation to take folic acid before conception.
Only 10 per cent consumed a multivitamin and mineral supplement during pregnancy. Despite the recommendation that all infants should be given 5ug of vitamin D from birth to one year, the study found vitamin D was given to fewer than 3.5 per cent of infants at six months of age.
The most recent national nutrition survey in 2011 reported that 28 per cent of Irish adults took a food supplement. Of the 211 different samples consumed, 30 per cent were multivitamin and mineral combinations, 20 per cent were fish oils and it was unclear how many took vitamin D supplements.
In its latest literature, the department suggests that you talk to your pharmacist or doctor about taking a vitamin D supplement as the typical Irish diet is low in this vitamin.
So while the evidence is there to demonstrate that certain population groups would benefit from specific supplements, few are taking them.
For some the cost is excessive. For others, compliance is the issue. Supplements lie forgotten at the back of many kitchen presses.
Multivitamins are frequently bought on a friend’s recommendations or as an impulse purchase from a pharmacy display.
Busy people may not know whether their diet is balanced or robust enough, and perhaps a supplement seems like a good safety net or nutritional insurance. Many expect a multivitamin and mineral preparation to boost energy levels or, at least, to offer protection from common infections.
Seeking answers
Questions worth considering with the help of your GP or other health professional include: What do you think the supplement will actually do? Is there any evidence it will work? Is it worth the money? Are you taking it just in case? Are there possible side effects?
Vitamin C supplements have been studied for years regarding prevention and treatment of colds. Results are inconsistent. A meta-analysis of 29 trials involving more than 11,000 participants found that supplementing with 200mg of vitamin C did not reduce the frequency of colds, but that it may slightly reduce their severity and duration.
Studies have also found that you may need to take a zinc supplement for at least five months before the risk of catching a cold is reduced. This can set you back about €44. Multiply that by four for a spouse and two children, and ask yourself whether it is worth it.
The Physicians Health Study involved nearly 15,000 male doctors, of whom half were chosen at random to take a daily multivitamin, and half were given a placebo. At the end of the 11-year study, Harvard researchers found that taking a multivitamin supplement did not reduce the risk of heart attacks, strokes, and death from cardiovascular disease.
However, it reduced the risk of being diagnosed with a new cancer by 8 per cent. This meant that out of every 1,000 men who took a multivitamin, 13 fewer were diagnosed with cancer.
The researchers concluded that it was unlikely that a multivitamin could replace a healthy diet that is high in fruit and vegetables.
As already mentioned, certain supplements certainly have benefits and may be of use depending on personal circumstances.
However, the heaviest users of vitamin and mineral supplements in the US are those who probably need them the least. They are well educated, have higher incomes, exercise and have healthy diets.
Fussy eaters
For younger family members,
Feed Your Child Well: Handbook for Parents in Ireland
, by three paediatric dietitians, is a better purchase than many food supplements targeting children.
The book suggests that if fussy eating continues for longer than four weeks, a multivitamin supplement with iron should be considered, but only after consultation with a health professional.
Again, certain toddlers and children who are vegetarian or vegan, or who have otherwise limited diets resulting from dental or digestive conditions, should discuss food supplements with their doctor.
Always check that the supplement is suitable for children and check the dosage.
Do you give your children supplements, and why?
Louise Reynolds
, consultant dietitian and mother of four children aged 13, 11, eight and six: “No I don’t. I did give them vitamin D as babies and tried to keep that going but, to be honest, the problem is compliance. I forget. I did buy fish oil supplements a few years ago but they were having none of it. They eat lots of fruit and veg, I use fortified milk for vitamin D, and they are big milk drinkers. The older two are great fish eaters. The younger two are getting there with oily fish, and fish pie is a family favourite.”
David Cunningham, cofounder of The Yoga Shala studio in Galway and chief executive of Counterweight Ireland, has four children: "We give the kids vitamins and the best food we can. All fish and vegetables, no meat. They eat everything we eat as adults. We also give vitamin D drops.You hear so much advice it's hard to know where to draw the line on supplements. With four children, it's expensive."
Dara Morgan, dietitian in private practice, Co Louth, has children who are five, eight and 10: "I don't give my children food supplements. My elder two girls eat a very varied diet and love their food. My boy, although somewhat fussier than his sisters, is improving all the time in terms of the variety he eats. I'm a real believer in food first when it comes to nutrition.
“The one food supplement I might consider for them is vitamin D and I’m watching this area of nutritional research with great interest. Food sources are few and far between and, bearing in mind our northerly latitude, the fact that we tend to reach for the sunscreen for our children at the first sight of summer sun and reports that vitamin D deficiency is more prevalent than previously thought, it’s one I wouldn’t rule out.
“My children all love salmon and the girls adore mackerel, both of which are good sources of vitamin D and are eaten regularly in our house but getting my own vitamin D status checked is on my to-do list.”
Paula Mee is a dietitian and a member of the Irish Nutrition and Dietetic Institute. See medfit.ie; @paula_mee
