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Do you take a vitamin supplement?
Conditions of Use
These days there seems to be a supplement on the supermarket shelf for almost every part of the body and nearly all of its functions. From eye and joint health to insomnia and mood support, there's a label vying for a slice of your attention as soon as you slip into the health care aisle.
While labels state that supplements are only useful if our diet is deficient, many of us still reach for the vitamin bottle as added insurance in our quest for health. But do we really need all these pills and can we be harming ourselves by giving them a try?
Yes, says Deakin University Associate Professor in Nutrition Tim Crowe, especially if you are taking a single nutrient supplement such as iron or zinc.
In reality, you should only think about taking supplements if you have an identified deficiency, a very poor diet or are a woman planning pregnancy.
In his view, the abundance of choice is giving us the wrong message that we need to be supplementing our diet with every single nutrient under the sun to stay healthy.
"The only supplement that should even be considered by the majority of the worried well is a broad spectrum vitamin and mineral supplement."
Sitting side by side on the shelf with multivitamins are what's known as 'single nutrient supplements' which contain just the one key vitamin or mineral as opposed to being part of a package of nutrients. Some of the common single nutrient supplements we take are vitamin C, B complex, calcium and vitamin E.
Up to one in four Australian adults take some form of vitamin at any one time, with women being higher users than men. An Australian Bureau of Statistics study found 82 per cent of people using supplements did so to prevent illness rather than to treat a pre-existing medical condition, yet there is no evidence to support the idea that this will keep you well.
"The scientific evidence is pretty clear that in the absence of a diagnosed deficiency, long-term use of vitamin and mineral supplements have little benefit," Crowe explains.
"Clinical trials involving hundreds of thousands of people have seen no differences in rates of cancer, heart disease, rates of dementia and mortality with long-term supplement use compared to people taking a placebo. The one rare standout situation where supplements have a clear benefit is taking folic acid before pregnancy to reduce the risk of spina bifida in the newborn."
So, should we be more mindful of the pills we pop and potions we drink in the name of good health? Can you overload your body on certain vitamins and minerals?
Crowe says that while overdosing on vitamins and minerals from food (including those fortified with nutrients) is extremely rare and almost impossible, supplements are a whole different story.
This is especially true with supplements where the dose can be much greater than would be found in a general multivitamin and mineral supplement.
Crowe says some common side effects that can occur from everyday vitamins include:
Doses of vitamin A at only a few times above the recommended dietary intake level can increase the risk of birth defects in the babies of pregnant women as well as central nervous system, liver, bone and skin disorders, Crowe warns.
He also cautions that accidental iron poisoning is the leading cause of poisoning deaths among young children.
"Children gain access to iron supplements because of it not being stored safely at home."
A balanced, healthy diet is really the best way to get your daily fill of goodness.
"Food is a complex mixture of vitamins, minerals and phytochemicals (plant chemicals), which all work together. Supplements tend to work in isolation and do not provide the benefits of phytochemicals and other components found in food," Crowe says.
"Taking vitamin and mineral supplements is no substitute for a varied diet."
Nutrition expert and dietitian Associate Professor Tim Crowe is from Deakin University's School of Exercise and Nutrition Sciences. He spoke with Karen Burge.