Vitamin and mineral supplementation is big money in the Western world. There is very limited data regarding the size of the industry, but the National Institute of Complementary Medicine says that as of 2001, the worldwide value of vitamin sales was estimated to be $AUD49 billion. It’s big business here in Australia. The National Health Survey showed that as of 2011-12, almost 1 in 3 (29%) Australians used a dietary supplement. More than half (16%) of this was multi-vitamin or multi-mineral supplements, with the remainder being fish oil. Working in community pharmacy during my high school and university years, I saw first-hand how commonplace supplements have become.
There is a place for vitamin and mineral supplements. The question is whether that place is a niche market for the few who really need them, or a booming industry for the worried well. With such a large percentage of us taking vitamin pills, I thought I’d give a run-down of what the science says.
Fact: In wealthy countries, multivitamins are only needed in rare instances.
If you’re eating an average Western diet and don’t have a serious medical disease, chances are you’re wasting your money on that multivitamin. Multivitamins are usually only recommended in isolated cases, for example people suffering from malnutrition (including anorexia nervosa) and diseases of malabsorption, such as cystic fibrosis. In Australia, studies of the population’s nutritional intake that have been conducted by public health bodies have regularly shown that, with the exception of some isolated nutrients such as calcium, we are doing very well. In fact, with current obesity levels in Australia being unprecedented, overnutrition (eating too much) and overall diet quality are now considered to be larger issues here than undernutrition.
Fact: Individual vitamin and mineral supplementation can occasionally be necessary.
If you are deficient in a vitamin or mineral, you’ll usually only need that specific nutrient- not a multivitamin.
For example, if you avoid eating dairy products, you may need a calcium supplement (although trying to include more sources of calcium in your diet, such as canned fish with bones or lactose-free products, is recommended). If you have been diagnosed with iron deficiency anaemia, you may need iron tablets. Likewise for Vitamin D. For women planning on becoming pregnant in the next 3 months, and in the first 3 months of pregnancy, public health bodies recommend a folic acid and iodine supplement to support the healthy development of the baby. Vegans will need foods fortified with Vitamin B12 and calcium or a supplement, and should also consider an algal omega-3 supplement. People who drink a large quantity of alcohol on an ongoing basis should consider a thiamin supplement (as well as seeking professional support).
What you probably don’t need is a multivitamin containing everything else.
Fact: More of a good thing is not better.
A lot of us who take vitamin pills take them as a safety net. The idea that taking a pill to make up for those days where our diet isn’t so great, on the surface, seems to make sense. However there’s no evidence that getting more than the Recommended Dietary Intake (RDI)- the amount that meets the nutrient requirements of 99% of the healthy population- has any health benefits. While any excess of water-soluble vitamins will just go down the toilet (see below), fat-soluble vitamins (Vitamins A, D, E, K) are stored in your body. Excesses of these can do damage.
Here in Australia, vitamin supplements containing Vitamin A must show a disclaimer that states ‘WARNING – When taken in excess of 3000 micrograms retinol equivalents, vitamin A can cause birth defects’. 2 studies with very large sample sizes conducted in the 1990’s discovered that, rather than reducing the risk of lung cancer as had been expected, Vitamin A supplementation increased the risk, as well as increasing overall mortality. There is also some evidence that Vitamin E may increase the risk of heart failure and overall mortality. Being acidic, chewable Vitamin C may increase the risk of dental caries.
One thing to keep in mind, too, is that science is constantly learning more about the effects of many of these supplements. For now, it’s probably best to keep to your fruit and vegetables to be safe.
Fact: Water-soluble vitamins get flushed down the toilet.
‘Water-soluble’ literally means ‘dissolves in water’. Water-soluble vitamins are Vitamin C and the B-group vitamins (Thiamin, riboflavin, niacin (B6), folate/folic acid, Vitamin B12, biotin and pantothenic acid). Your body takes what it needs from food, and excretes the rest out in your urine.
Fact: Supplements are not all clinically tested.
In Australia, the Therapeutic Goods Administration (TGA) divides therapeutic goods (including medicines and vitamins) into 2 classes: listed and registered. Vitamin supplements are usually classed as ‘listed’, although a select few are ‘registered’. Listed medicines (contain ‘Aust L’ on the label) are assessed as having a lower level of risk than those that need to be registered. Crucially, ‘listed’ medicines do not need to be tested to show that they actually work, and many may be no better than a placebo.
The Nutrition Information Panel of a packaged breakfast cereal sold in Australia. Note the number of vitamins and minerals that have been added (see bottom half of the table)
Fact: A lot of packaged foods are already fortified with vitamins.
Next time you eat breakfast cereal (if you eat it), look at the Nutrition Information Panel on the box. Chances are there’ll be a whole bucketload of vitamins and minerals added to the product. Also, in Australia as of 2009, all bread-making flour (except organic) must be fortified with iodine and folic acid. Iodine because Australian soil is very low in iodine, and Australia has high rates of iodine deficiency. Folic acid fortification was introduced as a means of reducing the rate of neural tube defects, like spina bifida.
So there you have it: 7 facts behind vitamin pills. Hopefully that’s helped clear some confusion! Of course, this is general advice for the average healthy population. If you want advice about your own situation, consult your GP or Accredited Practising Dietitian (APD).