The simple answer is: fortification.
The number of foods containing vitamin D organically is low and eating 22 eggs a day (the number you’d need to eat to reach the current recommended daily intake of vitamin D) is not a realistic target. Which is why food fortification – the process of enriching foods with added micronutrients – is becoming more and more popular, especially when it comes to vitamin D.
Where did food fortification start?
Food fortification harks back to the United States in the early 1900s where vitamin B3 was added to corn that was a staple for the poor. The difference between then and now is this fortification of corn was done to curb the rise of Pellagra – a disease brought on by vitamin B3 deficiency – whereas foods containing added micronutrients nowadays often do so for optimum health rather than for preventative measures.
Aren’t there enough foods high in vitamin D?
Foods containing vitamin D – oily fish is the main source but liver, mushrooms and eggs contain it, too – do exist. The problem is there’s not many of them and to get the recommended 10mcg a day you’d have to eat them in very large quantities.
Sunshine is the main source of vitamin D but you’ve likely noticed its disappearance in recent weeks. Your skin reacts in a particular way with sunlight - when the UV index is above 3 – that produces vitamin D but during the winter months in Britain the UV index stays below 3. In summer, half an hour outside each day in short sleeves gives your body the chance to produce enough vitamin D but in winter this is sadly not the case.
Enter fortified margarine
After the First World War the British Government introduced mandatory fortification of margarine with vitamins A & D, because butter was unavailable as a source of both. The same followed for white flour in the 1930s, but with calcium, iron, thiamine and niacin. The fortification of these products is ongoing so the margarine you buy today is in fact fortified with vitamin D.
Food fortification: the debate
There is some debate over whether everyone should eat fortified foods as a result of those that don’t consume enough of a certain vitamin, but when it comes to fortification there is method to the (not so mad) madness. For example, margarine is fortified with vitamin D but not low-fat spreads, and white flour is fortified with calcium, iron, thiamine and niacin when wholemeal flour isn’t. There are always options - unless you have a real craving for a particular type of cornflakes, that is.
And when it comes to vitamin D – this is a vitamin many of us simply don’t get enough of. In Northern European countries, where sunlight hours in the winter are minimal, the fortification of certain foods with vitamin D has become increasingly mandatory because – as you can imagine – vitamin D deficiency is a real risk.
Public Health England now recommends that all Britons take vitamin D supplements in the winter due to it being impossible to make sufficient amounts during this season.
Times are changing
It’s not just the lack of sunlight that’s led to increased food fortification; it’s us. Vitamin D has become increasingly interesting to health professionals not just because of its seemingly endless list of health benefits (a new study suggests vitamin D could help burns to heal and prevent scarring ) but because of our modern way of living. Our vitamin D intake is declining partly because:
- We’re now more careful when it comes to sun exposure
- We don’t eat as much food high in vitamin D as we used to
- We eat smaller quantities than we used to due to being less active, and eating less calories means consuming less chance of meeting your RDA’s (Recommended Daily Allowances).