Fortified food: should we really be pumping bread with Vitamin D?

Marks & Spencer has started adding Vitamin D to its packaged bread. But is stuffing food with extra nutrients really a good idea?

Marks & Spencer bread
Crumbs: Marks & Spencer is adding Vitamin D to its bread products Credit: Photo: Marks & Spencer

Marks & Spencer has started adding Vitamin D to its packaged bread in response to customer concerns they’re not getting their recommended daily amount. But bread isn’t the only basic food item that comes pumped with extra nutrients – eggs, milk, breakfast cereals, flour and even water is sold with vitamins and minerals added in. But is it necessary and is it always good for us?

According to The British Nutrition foundation, fortified foods can be crucial for people whose diets lack key nutrients. Research suggests, for example, that around 50 per cent of all UK adults are lacking in Vitamin D to some degree. Deficiencies in children are a particular concern, as the 19th century disease rickets has returned to the UK in recent years. The problem with Vitamin D is that there are few dietary sources – our main supply is from the sun. With long nights in winter and limited sunlight even during the summer, it’s difficult to get our daily requirement though sunlight alone.

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“It is possible to get all our vitamins from a healthy balanced diet but many people don’t have access to this, so there can be justification for fortifying some foods,” says Jeannette Jackson, nutritionist and author of The Drop Zone Diet. “This ensures some vulnerable groups like children and the elderly get the correct ratio of vitamins daily.” She says when foods are refined, some of the naturally occurring nutrients are lost, so fortification just adds these back in.

Cereals

Many cereals are advertised as fortified, but aren't particularly good for you (ALAMY)

But other foods are fortified purely for commercial reasons. The health benefits of adding protein to foods like water and ice cream, for example, are less clear. According to Health Department guidelines, an adult needs around 50g of protein per day (although requirements for different risk groups vary) and there’s no evidence that as a nation we’re deficient. But eating more than we need of something, even if it’s good for us, is not necessarily healthy. A recent Dutch study suggested a high-protein diet could cause “chronic kidney injury” as the body struggles to process more protein than it needs.

Some experts have also raised concerns about manufacturers who add vitamins and minerals to create a healthy “halo effect” around foods that contain lots of sugar and salt, such as some breakfast cereals. A 1999 report by the UK’s then Food Commission suggested fortified foods undermined good nutrition. It surveyed 260 foods that promoted fortification on their labels and found that almost three-quarters were high in fat, sugar or salt. It suggested that the addition of vitamins and minerals was a marketing ploy to promote processed foods.

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A report last year by the US health research organisation Environmental Working Group, found that a glut of foods with added vitamins and minerals, namely breakfast cereals and snack bars, were a potential health risk to children and pregnant women when taken along with vitamin supplements. It found nearly half of US children under the age of 8 ingested potentially harmful amounts of Vitamin A, zinc and niacin due to excessive food fortification. (The NHS says your daily intake of Vitamin A from food and supplements should not exceed 1.5mg).

Jeannette Jackson agrees that consumers should eat fortified food cautiously. Those who graze on fortified breakfast cereal throughout the day, for example, could end up having too much of a good thing, and develop damaged bones, hair or nails. She added that the nutrients added to foods were not as effective as those found naturally in them, and that it was better to eat a balanced diet of whole, unprocessed food.

“I would always advocate that people aim to get their vitamins and minerals from natural sources and get plenty or fresh air, regardless of the weather. You don’t need sunshine to make vitamin D, just sunlight,” she says.

Commonly fortified foods

Breakfast cereals

These widely contain fortified flour, as well as a range of other added nutrients including calcium, iron and Vitamins A and D. The British Nutrition Foundation estimates breakfast cereals contribute 20–30 per cent of the average iron intake for British consumers, and 13–24% of their Vitamin D intake.

Margarine and spreads

Many margarine manufacturers add Vitamins A and D, so that the products contain similar levels as butter. Some spreads also contain added Omega 3.

Flour

Under UK law, all wheat flour except wholemeal must be fortified with calcium, iron, niacin and thiamine. The Government is currently considering extending this to include folic acid in a bid to reduce neural tube defects in foetuses.

Dairy

Although widely available in other countries including Australia, fortified milk is not widely available in the UK, although M&S produces a range of cow’s milk and yoghurt fortified with Vitamin D and Omega 3. Some yoghurt also contains added fibre.

Fruit juice

This is commonly fortified with Vitamin C and other vitamins, as well as calcium and Omega 3

Eggs

Eggs enriched with Omega 3 are now widely available. The hens eat a specially formulated Omega 3-rich diet containing things like linseed and salmon oil.

Bread

Now widely available with added Omega 3 and sold by M&S with added Vitamin D.