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Many Danes take dietary supplements although few need them

Food, fish and agriculture Nutrition and dietary habits Health-promoting compounds

Six out of ten Danes take a dietary supplement even though the majority has an adequate intake of most vitamins and minerals from their diet alone. For many the use of these supplements is unnecessary, and for some it can lead to excessive intakes according to a new analysis from the National Food Institute, Technical University of Denmark.

Even though there are no recommendations that the general population should take dietary supplements, six out of ten Danes take at least one vitamin and/or mineral supplement.

Problems with vitamin D and iron

The vast majority of the Danish population gets an adequate amount of vitamins and minerals through their diet. However, vitamin D and iron are two general exceptions. While the need for vitamin D is mainly met through sunlight during the summer, the diet is the primary source of vitamin D during winter. Almost all Danes get an inadequate amount from the diet. Furthermore, women of childbearing age have an inadequate intake of iron.

"The majority of Danes do not need to take a supplement as a healthy and balanced diet and thoughtful sun exposure are the best ways to meet the need for most vitamins and minerals. If people still want to take a supplement they should choose them wisely."

New figures from the National Food Institute show that 62% of 11-17-year-olds and 34% of adults have a very high probability of having an inadequate intake of vitamin D from their diet. Even among users of supplements there is a risk that 35% of the 11-17-year-olds and 26% of the 18-50-year-olds have an inadequate vitamin D intake.

When it comes to iron the dietary intake is inadequate among 79% of the 14-17-year-old girls and 53% of the 18-50-year-old women. Although significantly fewer of those who take supplements have an inadequate intake, there are still 27% of the 14-17-year-old girls who have an inadequate iron intake.

Risk of excessive intakes

People who do not take supplements generally have an intake of vitamins and minerals through their diet, which is below the upper tolerable limits. However some 4-10-year-olds exceed the limit for retinol (30%), which is a vitamin A, as well zinc (73%) through their diet alone. This is because they tend to favor foods that are rich in these nutrients such as liver paste.

Not surprisingly the use of supplements leads to an increase in the proportion of especially 4-6-year-olds who exceed the upper tolerable limits for retinol (43%), iron (45%) and zinc (73%). Among 7-10-year-old and 11-14-year-old supplement users respectively the limits for zinc (46 and 25%), and to a lesser extent retinol (21 and 10%) are exceeded. Adult supplement users also have smaller exceedances of the limits for retinol and zinc.

”Supplements always have the same high content of vitamins and minerals unlike a varied and seasonal diet. Therefore regular users of supplements can end up exceeding the upper tolerable limits for an extended period of time,” senior researcher Anja Biltoft-Jensen from the National Food Institute says.

Prolonged exceedances are concerning. This is particularly so in the case of retinol, where the upper tolerable limit for the general population has been set to protect against liver damage.

Use supplements wisely

“The majority of Danes do not need to take a supplement as a healthy and balanced diet and thoughtful sun exposure are the best ways to meet the need for most vitamins and minerals. If people still want to take a supplement they should choose them wisely,” Anja Biltoft-Jensen advises.

"As far as possible buy supplements that contain less than 100% of the reference intake for vitamin A and zinc in all supplements as well as iron in supplements for children to avoid intakes that are higher than what we consider tolerable. Also avoid mega doses unless a doctor has advised that you do, as it can be dangerous to give children as well as adults high doses of vitamins and minerals. And last but not least, it is important that children receive products intended for children," she emphasizes.

Read more

The results from the analysis have been described in further detail in the National Food Institute’s e-article: De fleste får nok vitaminer og mineraler fra kosten alene (pdf – available in Danish only).

Data from the Danish national survey of diet and physical activity, DANSDA, collected in 2011-2013 was used in the analysis.

Facts about supplements

There are no recommendations for the general Danish population to take supplements. The Danish Veterinary and Food Administration recommends that only certain groups of the population take a supplement, including infants, women who plan to become or are pregnant, people over 70, people with dark skin or covered persons.